hooks.c revision 7f1fb60c4fc9fb29fbb406ac8c4cfb4e59e168d6
1/* 2 * NSA Security-Enhanced Linux (SELinux) security module 3 * 4 * This file contains the SELinux hook function implementations. 5 * 6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil> 7 * Chris Vance, <cvance@nai.com> 8 * Wayne Salamon, <wsalamon@nai.com> 9 * James Morris <jmorris@redhat.com> 10 * 11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc. 12 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com> 13 * Eric Paris <eparis@redhat.com> 14 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. 15 * <dgoeddel@trustedcs.com> 16 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P. 17 * Paul Moore <paul@paul-moore.com> 18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. 19 * Yuichi Nakamura <ynakam@hitachisoft.jp> 20 * 21 * This program is free software; you can redistribute it and/or modify 22 * it under the terms of the GNU General Public License version 2, 23 * as published by the Free Software Foundation. 24 */ 25 26#include <linux/init.h> 27#include <linux/kd.h> 28#include <linux/kernel.h> 29#include <linux/tracehook.h> 30#include <linux/errno.h> 31#include <linux/ext2_fs.h> 32#include <linux/sched.h> 33#include <linux/security.h> 34#include <linux/xattr.h> 35#include <linux/capability.h> 36#include <linux/unistd.h> 37#include <linux/mm.h> 38#include <linux/mman.h> 39#include <linux/slab.h> 40#include <linux/pagemap.h> 41#include <linux/proc_fs.h> 42#include <linux/swap.h> 43#include <linux/spinlock.h> 44#include <linux/syscalls.h> 45#include <linux/dcache.h> 46#include <linux/file.h> 47#include <linux/fdtable.h> 48#include <linux/namei.h> 49#include <linux/mount.h> 50#include <linux/netfilter_ipv4.h> 51#include <linux/netfilter_ipv6.h> 52#include <linux/tty.h> 53#include <net/icmp.h> 54#include <net/ip.h> /* for local_port_range[] */ 55#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ 56#include <net/net_namespace.h> 57#include <net/netlabel.h> 58#include <linux/uaccess.h> 59#include <asm/ioctls.h> 60#include <linux/atomic.h> 61#include <linux/bitops.h> 62#include <linux/interrupt.h> 63#include <linux/netdevice.h> /* for network interface checks */ 64#include <linux/netlink.h> 65#include <linux/tcp.h> 66#include <linux/udp.h> 67#include <linux/dccp.h> 68#include <linux/quota.h> 69#include <linux/un.h> /* for Unix socket types */ 70#include <net/af_unix.h> /* for Unix socket types */ 71#include <linux/parser.h> 72#include <linux/nfs_mount.h> 73#include <net/ipv6.h> 74#include <linux/hugetlb.h> 75#include <linux/personality.h> 76#include <linux/audit.h> 77#include <linux/string.h> 78#include <linux/selinux.h> 79#include <linux/mutex.h> 80#include <linux/posix-timers.h> 81#include <linux/syslog.h> 82#include <linux/user_namespace.h> 83#include <linux/export.h> 84 85#include "avc.h" 86#include "objsec.h" 87#include "netif.h" 88#include "netnode.h" 89#include "netport.h" 90#include "xfrm.h" 91#include "netlabel.h" 92#include "audit.h" 93#include "avc_ss.h" 94 95#define NUM_SEL_MNT_OPTS 5 96 97extern struct security_operations *security_ops; 98 99/* SECMARK reference count */ 100static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); 101 102#ifdef CONFIG_SECURITY_SELINUX_DEVELOP 103int selinux_enforcing; 104 105static int __init enforcing_setup(char *str) 106{ 107 unsigned long enforcing; 108 if (!strict_strtoul(str, 0, &enforcing)) 109 selinux_enforcing = enforcing ? 1 : 0; 110 return 1; 111} 112__setup("enforcing=", enforcing_setup); 113#endif 114 115#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM 116int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; 117 118static int __init selinux_enabled_setup(char *str) 119{ 120 unsigned long enabled; 121 if (!strict_strtoul(str, 0, &enabled)) 122 selinux_enabled = enabled ? 1 : 0; 123 return 1; 124} 125__setup("selinux=", selinux_enabled_setup); 126#else 127int selinux_enabled = 1; 128#endif 129 130static struct kmem_cache *sel_inode_cache; 131 132/** 133 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled 134 * 135 * Description: 136 * This function checks the SECMARK reference counter to see if any SECMARK 137 * targets are currently configured, if the reference counter is greater than 138 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is 139 * enabled, false (0) if SECMARK is disabled. 140 * 141 */ 142static int selinux_secmark_enabled(void) 143{ 144 return (atomic_read(&selinux_secmark_refcount) > 0); 145} 146 147/* 148 * initialise the security for the init task 149 */ 150static void cred_init_security(void) 151{ 152 struct cred *cred = (struct cred *) current->real_cred; 153 struct task_security_struct *tsec; 154 155 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); 156 if (!tsec) 157 panic("SELinux: Failed to initialize initial task.\n"); 158 159 tsec->osid = tsec->sid = SECINITSID_KERNEL; 160 cred->security = tsec; 161} 162 163/* 164 * get the security ID of a set of credentials 165 */ 166static inline u32 cred_sid(const struct cred *cred) 167{ 168 const struct task_security_struct *tsec; 169 170 tsec = cred->security; 171 return tsec->sid; 172} 173 174/* 175 * get the objective security ID of a task 176 */ 177static inline u32 task_sid(const struct task_struct *task) 178{ 179 u32 sid; 180 181 rcu_read_lock(); 182 sid = cred_sid(__task_cred(task)); 183 rcu_read_unlock(); 184 return sid; 185} 186 187/* 188 * get the subjective security ID of the current task 189 */ 190static inline u32 current_sid(void) 191{ 192 const struct task_security_struct *tsec = current_security(); 193 194 return tsec->sid; 195} 196 197/* Allocate and free functions for each kind of security blob. */ 198 199static int inode_alloc_security(struct inode *inode) 200{ 201 struct inode_security_struct *isec; 202 u32 sid = current_sid(); 203 204 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); 205 if (!isec) 206 return -ENOMEM; 207 208 mutex_init(&isec->lock); 209 INIT_LIST_HEAD(&isec->list); 210 isec->inode = inode; 211 isec->sid = SECINITSID_UNLABELED; 212 isec->sclass = SECCLASS_FILE; 213 isec->task_sid = sid; 214 inode->i_security = isec; 215 216 return 0; 217} 218 219static void inode_free_security(struct inode *inode) 220{ 221 struct inode_security_struct *isec = inode->i_security; 222 struct superblock_security_struct *sbsec = inode->i_sb->s_security; 223 224 spin_lock(&sbsec->isec_lock); 225 if (!list_empty(&isec->list)) 226 list_del_init(&isec->list); 227 spin_unlock(&sbsec->isec_lock); 228 229 inode->i_security = NULL; 230 kmem_cache_free(sel_inode_cache, isec); 231} 232 233static int file_alloc_security(struct file *file) 234{ 235 struct file_security_struct *fsec; 236 u32 sid = current_sid(); 237 238 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); 239 if (!fsec) 240 return -ENOMEM; 241 242 fsec->sid = sid; 243 fsec->fown_sid = sid; 244 file->f_security = fsec; 245 246 return 0; 247} 248 249static void file_free_security(struct file *file) 250{ 251 struct file_security_struct *fsec = file->f_security; 252 file->f_security = NULL; 253 kfree(fsec); 254} 255 256static int superblock_alloc_security(struct super_block *sb) 257{ 258 struct superblock_security_struct *sbsec; 259 260 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); 261 if (!sbsec) 262 return -ENOMEM; 263 264 mutex_init(&sbsec->lock); 265 INIT_LIST_HEAD(&sbsec->isec_head); 266 spin_lock_init(&sbsec->isec_lock); 267 sbsec->sb = sb; 268 sbsec->sid = SECINITSID_UNLABELED; 269 sbsec->def_sid = SECINITSID_FILE; 270 sbsec->mntpoint_sid = SECINITSID_UNLABELED; 271 sb->s_security = sbsec; 272 273 return 0; 274} 275 276static void superblock_free_security(struct super_block *sb) 277{ 278 struct superblock_security_struct *sbsec = sb->s_security; 279 sb->s_security = NULL; 280 kfree(sbsec); 281} 282 283/* The file system's label must be initialized prior to use. */ 284 285static const char *labeling_behaviors[6] = { 286 "uses xattr", 287 "uses transition SIDs", 288 "uses task SIDs", 289 "uses genfs_contexts", 290 "not configured for labeling", 291 "uses mountpoint labeling", 292}; 293 294static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); 295 296static inline int inode_doinit(struct inode *inode) 297{ 298 return inode_doinit_with_dentry(inode, NULL); 299} 300 301enum { 302 Opt_error = -1, 303 Opt_context = 1, 304 Opt_fscontext = 2, 305 Opt_defcontext = 3, 306 Opt_rootcontext = 4, 307 Opt_labelsupport = 5, 308}; 309 310static const match_table_t tokens = { 311 {Opt_context, CONTEXT_STR "%s"}, 312 {Opt_fscontext, FSCONTEXT_STR "%s"}, 313 {Opt_defcontext, DEFCONTEXT_STR "%s"}, 314 {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, 315 {Opt_labelsupport, LABELSUPP_STR}, 316 {Opt_error, NULL}, 317}; 318 319#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" 320 321static int may_context_mount_sb_relabel(u32 sid, 322 struct superblock_security_struct *sbsec, 323 const struct cred *cred) 324{ 325 const struct task_security_struct *tsec = cred->security; 326 int rc; 327 328 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 329 FILESYSTEM__RELABELFROM, NULL); 330 if (rc) 331 return rc; 332 333 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, 334 FILESYSTEM__RELABELTO, NULL); 335 return rc; 336} 337 338static int may_context_mount_inode_relabel(u32 sid, 339 struct superblock_security_struct *sbsec, 340 const struct cred *cred) 341{ 342 const struct task_security_struct *tsec = cred->security; 343 int rc; 344 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 345 FILESYSTEM__RELABELFROM, NULL); 346 if (rc) 347 return rc; 348 349 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, 350 FILESYSTEM__ASSOCIATE, NULL); 351 return rc; 352} 353 354static int sb_finish_set_opts(struct super_block *sb) 355{ 356 struct superblock_security_struct *sbsec = sb->s_security; 357 struct dentry *root = sb->s_root; 358 struct inode *root_inode = root->d_inode; 359 int rc = 0; 360 361 if (sbsec->behavior == SECURITY_FS_USE_XATTR) { 362 /* Make sure that the xattr handler exists and that no 363 error other than -ENODATA is returned by getxattr on 364 the root directory. -ENODATA is ok, as this may be 365 the first boot of the SELinux kernel before we have 366 assigned xattr values to the filesystem. */ 367 if (!root_inode->i_op->getxattr) { 368 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " 369 "xattr support\n", sb->s_id, sb->s_type->name); 370 rc = -EOPNOTSUPP; 371 goto out; 372 } 373 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); 374 if (rc < 0 && rc != -ENODATA) { 375 if (rc == -EOPNOTSUPP) 376 printk(KERN_WARNING "SELinux: (dev %s, type " 377 "%s) has no security xattr handler\n", 378 sb->s_id, sb->s_type->name); 379 else 380 printk(KERN_WARNING "SELinux: (dev %s, type " 381 "%s) getxattr errno %d\n", sb->s_id, 382 sb->s_type->name, -rc); 383 goto out; 384 } 385 } 386 387 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP); 388 389 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 390 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", 391 sb->s_id, sb->s_type->name); 392 else 393 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", 394 sb->s_id, sb->s_type->name, 395 labeling_behaviors[sbsec->behavior-1]); 396 397 if (sbsec->behavior == SECURITY_FS_USE_GENFS || 398 sbsec->behavior == SECURITY_FS_USE_MNTPOINT || 399 sbsec->behavior == SECURITY_FS_USE_NONE || 400 sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 401 sbsec->flags &= ~SE_SBLABELSUPP; 402 403 /* Special handling for sysfs. Is genfs but also has setxattr handler*/ 404 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0) 405 sbsec->flags |= SE_SBLABELSUPP; 406 407 /* Initialize the root inode. */ 408 rc = inode_doinit_with_dentry(root_inode, root); 409 410 /* Initialize any other inodes associated with the superblock, e.g. 411 inodes created prior to initial policy load or inodes created 412 during get_sb by a pseudo filesystem that directly 413 populates itself. */ 414 spin_lock(&sbsec->isec_lock); 415next_inode: 416 if (!list_empty(&sbsec->isec_head)) { 417 struct inode_security_struct *isec = 418 list_entry(sbsec->isec_head.next, 419 struct inode_security_struct, list); 420 struct inode *inode = isec->inode; 421 spin_unlock(&sbsec->isec_lock); 422 inode = igrab(inode); 423 if (inode) { 424 if (!IS_PRIVATE(inode)) 425 inode_doinit(inode); 426 iput(inode); 427 } 428 spin_lock(&sbsec->isec_lock); 429 list_del_init(&isec->list); 430 goto next_inode; 431 } 432 spin_unlock(&sbsec->isec_lock); 433out: 434 return rc; 435} 436 437/* 438 * This function should allow an FS to ask what it's mount security 439 * options were so it can use those later for submounts, displaying 440 * mount options, or whatever. 441 */ 442static int selinux_get_mnt_opts(const struct super_block *sb, 443 struct security_mnt_opts *opts) 444{ 445 int rc = 0, i; 446 struct superblock_security_struct *sbsec = sb->s_security; 447 char *context = NULL; 448 u32 len; 449 char tmp; 450 451 security_init_mnt_opts(opts); 452 453 if (!(sbsec->flags & SE_SBINITIALIZED)) 454 return -EINVAL; 455 456 if (!ss_initialized) 457 return -EINVAL; 458 459 tmp = sbsec->flags & SE_MNTMASK; 460 /* count the number of mount options for this sb */ 461 for (i = 0; i < 8; i++) { 462 if (tmp & 0x01) 463 opts->num_mnt_opts++; 464 tmp >>= 1; 465 } 466 /* Check if the Label support flag is set */ 467 if (sbsec->flags & SE_SBLABELSUPP) 468 opts->num_mnt_opts++; 469 470 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); 471 if (!opts->mnt_opts) { 472 rc = -ENOMEM; 473 goto out_free; 474 } 475 476 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); 477 if (!opts->mnt_opts_flags) { 478 rc = -ENOMEM; 479 goto out_free; 480 } 481 482 i = 0; 483 if (sbsec->flags & FSCONTEXT_MNT) { 484 rc = security_sid_to_context(sbsec->sid, &context, &len); 485 if (rc) 486 goto out_free; 487 opts->mnt_opts[i] = context; 488 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; 489 } 490 if (sbsec->flags & CONTEXT_MNT) { 491 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); 492 if (rc) 493 goto out_free; 494 opts->mnt_opts[i] = context; 495 opts->mnt_opts_flags[i++] = CONTEXT_MNT; 496 } 497 if (sbsec->flags & DEFCONTEXT_MNT) { 498 rc = security_sid_to_context(sbsec->def_sid, &context, &len); 499 if (rc) 500 goto out_free; 501 opts->mnt_opts[i] = context; 502 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; 503 } 504 if (sbsec->flags & ROOTCONTEXT_MNT) { 505 struct inode *root = sbsec->sb->s_root->d_inode; 506 struct inode_security_struct *isec = root->i_security; 507 508 rc = security_sid_to_context(isec->sid, &context, &len); 509 if (rc) 510 goto out_free; 511 opts->mnt_opts[i] = context; 512 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; 513 } 514 if (sbsec->flags & SE_SBLABELSUPP) { 515 opts->mnt_opts[i] = NULL; 516 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP; 517 } 518 519 BUG_ON(i != opts->num_mnt_opts); 520 521 return 0; 522 523out_free: 524 security_free_mnt_opts(opts); 525 return rc; 526} 527 528static int bad_option(struct superblock_security_struct *sbsec, char flag, 529 u32 old_sid, u32 new_sid) 530{ 531 char mnt_flags = sbsec->flags & SE_MNTMASK; 532 533 /* check if the old mount command had the same options */ 534 if (sbsec->flags & SE_SBINITIALIZED) 535 if (!(sbsec->flags & flag) || 536 (old_sid != new_sid)) 537 return 1; 538 539 /* check if we were passed the same options twice, 540 * aka someone passed context=a,context=b 541 */ 542 if (!(sbsec->flags & SE_SBINITIALIZED)) 543 if (mnt_flags & flag) 544 return 1; 545 return 0; 546} 547 548/* 549 * Allow filesystems with binary mount data to explicitly set mount point 550 * labeling information. 551 */ 552static int selinux_set_mnt_opts(struct super_block *sb, 553 struct security_mnt_opts *opts) 554{ 555 const struct cred *cred = current_cred(); 556 int rc = 0, i; 557 struct superblock_security_struct *sbsec = sb->s_security; 558 const char *name = sb->s_type->name; 559 struct inode *inode = sbsec->sb->s_root->d_inode; 560 struct inode_security_struct *root_isec = inode->i_security; 561 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; 562 u32 defcontext_sid = 0; 563 char **mount_options = opts->mnt_opts; 564 int *flags = opts->mnt_opts_flags; 565 int num_opts = opts->num_mnt_opts; 566 567 mutex_lock(&sbsec->lock); 568 569 if (!ss_initialized) { 570 if (!num_opts) { 571 /* Defer initialization until selinux_complete_init, 572 after the initial policy is loaded and the security 573 server is ready to handle calls. */ 574 goto out; 575 } 576 rc = -EINVAL; 577 printk(KERN_WARNING "SELinux: Unable to set superblock options " 578 "before the security server is initialized\n"); 579 goto out; 580 } 581 582 /* 583 * Binary mount data FS will come through this function twice. Once 584 * from an explicit call and once from the generic calls from the vfs. 585 * Since the generic VFS calls will not contain any security mount data 586 * we need to skip the double mount verification. 587 * 588 * This does open a hole in which we will not notice if the first 589 * mount using this sb set explict options and a second mount using 590 * this sb does not set any security options. (The first options 591 * will be used for both mounts) 592 */ 593 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 594 && (num_opts == 0)) 595 goto out; 596 597 /* 598 * parse the mount options, check if they are valid sids. 599 * also check if someone is trying to mount the same sb more 600 * than once with different security options. 601 */ 602 for (i = 0; i < num_opts; i++) { 603 u32 sid; 604 605 if (flags[i] == SE_SBLABELSUPP) 606 continue; 607 rc = security_context_to_sid(mount_options[i], 608 strlen(mount_options[i]), &sid); 609 if (rc) { 610 printk(KERN_WARNING "SELinux: security_context_to_sid" 611 "(%s) failed for (dev %s, type %s) errno=%d\n", 612 mount_options[i], sb->s_id, name, rc); 613 goto out; 614 } 615 switch (flags[i]) { 616 case FSCONTEXT_MNT: 617 fscontext_sid = sid; 618 619 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, 620 fscontext_sid)) 621 goto out_double_mount; 622 623 sbsec->flags |= FSCONTEXT_MNT; 624 break; 625 case CONTEXT_MNT: 626 context_sid = sid; 627 628 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, 629 context_sid)) 630 goto out_double_mount; 631 632 sbsec->flags |= CONTEXT_MNT; 633 break; 634 case ROOTCONTEXT_MNT: 635 rootcontext_sid = sid; 636 637 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, 638 rootcontext_sid)) 639 goto out_double_mount; 640 641 sbsec->flags |= ROOTCONTEXT_MNT; 642 643 break; 644 case DEFCONTEXT_MNT: 645 defcontext_sid = sid; 646 647 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, 648 defcontext_sid)) 649 goto out_double_mount; 650 651 sbsec->flags |= DEFCONTEXT_MNT; 652 653 break; 654 default: 655 rc = -EINVAL; 656 goto out; 657 } 658 } 659 660 if (sbsec->flags & SE_SBINITIALIZED) { 661 /* previously mounted with options, but not on this attempt? */ 662 if ((sbsec->flags & SE_MNTMASK) && !num_opts) 663 goto out_double_mount; 664 rc = 0; 665 goto out; 666 } 667 668 if (strcmp(sb->s_type->name, "proc") == 0) 669 sbsec->flags |= SE_SBPROC; 670 671 /* Determine the labeling behavior to use for this filesystem type. */ 672 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid); 673 if (rc) { 674 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n", 675 __func__, sb->s_type->name, rc); 676 goto out; 677 } 678 679 /* sets the context of the superblock for the fs being mounted. */ 680 if (fscontext_sid) { 681 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); 682 if (rc) 683 goto out; 684 685 sbsec->sid = fscontext_sid; 686 } 687 688 /* 689 * Switch to using mount point labeling behavior. 690 * sets the label used on all file below the mountpoint, and will set 691 * the superblock context if not already set. 692 */ 693 if (context_sid) { 694 if (!fscontext_sid) { 695 rc = may_context_mount_sb_relabel(context_sid, sbsec, 696 cred); 697 if (rc) 698 goto out; 699 sbsec->sid = context_sid; 700 } else { 701 rc = may_context_mount_inode_relabel(context_sid, sbsec, 702 cred); 703 if (rc) 704 goto out; 705 } 706 if (!rootcontext_sid) 707 rootcontext_sid = context_sid; 708 709 sbsec->mntpoint_sid = context_sid; 710 sbsec->behavior = SECURITY_FS_USE_MNTPOINT; 711 } 712 713 if (rootcontext_sid) { 714 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, 715 cred); 716 if (rc) 717 goto out; 718 719 root_isec->sid = rootcontext_sid; 720 root_isec->initialized = 1; 721 } 722 723 if (defcontext_sid) { 724 if (sbsec->behavior != SECURITY_FS_USE_XATTR) { 725 rc = -EINVAL; 726 printk(KERN_WARNING "SELinux: defcontext option is " 727 "invalid for this filesystem type\n"); 728 goto out; 729 } 730 731 if (defcontext_sid != sbsec->def_sid) { 732 rc = may_context_mount_inode_relabel(defcontext_sid, 733 sbsec, cred); 734 if (rc) 735 goto out; 736 } 737 738 sbsec->def_sid = defcontext_sid; 739 } 740 741 rc = sb_finish_set_opts(sb); 742out: 743 mutex_unlock(&sbsec->lock); 744 return rc; 745out_double_mount: 746 rc = -EINVAL; 747 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " 748 "security settings for (dev %s, type %s)\n", sb->s_id, name); 749 goto out; 750} 751 752static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb, 753 struct super_block *newsb) 754{ 755 const struct superblock_security_struct *oldsbsec = oldsb->s_security; 756 struct superblock_security_struct *newsbsec = newsb->s_security; 757 758 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); 759 int set_context = (oldsbsec->flags & CONTEXT_MNT); 760 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); 761 762 /* 763 * if the parent was able to be mounted it clearly had no special lsm 764 * mount options. thus we can safely deal with this superblock later 765 */ 766 if (!ss_initialized) 767 return; 768 769 /* how can we clone if the old one wasn't set up?? */ 770 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); 771 772 /* if fs is reusing a sb, just let its options stand... */ 773 if (newsbsec->flags & SE_SBINITIALIZED) 774 return; 775 776 mutex_lock(&newsbsec->lock); 777 778 newsbsec->flags = oldsbsec->flags; 779 780 newsbsec->sid = oldsbsec->sid; 781 newsbsec->def_sid = oldsbsec->def_sid; 782 newsbsec->behavior = oldsbsec->behavior; 783 784 if (set_context) { 785 u32 sid = oldsbsec->mntpoint_sid; 786 787 if (!set_fscontext) 788 newsbsec->sid = sid; 789 if (!set_rootcontext) { 790 struct inode *newinode = newsb->s_root->d_inode; 791 struct inode_security_struct *newisec = newinode->i_security; 792 newisec->sid = sid; 793 } 794 newsbsec->mntpoint_sid = sid; 795 } 796 if (set_rootcontext) { 797 const struct inode *oldinode = oldsb->s_root->d_inode; 798 const struct inode_security_struct *oldisec = oldinode->i_security; 799 struct inode *newinode = newsb->s_root->d_inode; 800 struct inode_security_struct *newisec = newinode->i_security; 801 802 newisec->sid = oldisec->sid; 803 } 804 805 sb_finish_set_opts(newsb); 806 mutex_unlock(&newsbsec->lock); 807} 808 809static int selinux_parse_opts_str(char *options, 810 struct security_mnt_opts *opts) 811{ 812 char *p; 813 char *context = NULL, *defcontext = NULL; 814 char *fscontext = NULL, *rootcontext = NULL; 815 int rc, num_mnt_opts = 0; 816 817 opts->num_mnt_opts = 0; 818 819 /* Standard string-based options. */ 820 while ((p = strsep(&options, "|")) != NULL) { 821 int token; 822 substring_t args[MAX_OPT_ARGS]; 823 824 if (!*p) 825 continue; 826 827 token = match_token(p, tokens, args); 828 829 switch (token) { 830 case Opt_context: 831 if (context || defcontext) { 832 rc = -EINVAL; 833 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 834 goto out_err; 835 } 836 context = match_strdup(&args[0]); 837 if (!context) { 838 rc = -ENOMEM; 839 goto out_err; 840 } 841 break; 842 843 case Opt_fscontext: 844 if (fscontext) { 845 rc = -EINVAL; 846 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 847 goto out_err; 848 } 849 fscontext = match_strdup(&args[0]); 850 if (!fscontext) { 851 rc = -ENOMEM; 852 goto out_err; 853 } 854 break; 855 856 case Opt_rootcontext: 857 if (rootcontext) { 858 rc = -EINVAL; 859 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 860 goto out_err; 861 } 862 rootcontext = match_strdup(&args[0]); 863 if (!rootcontext) { 864 rc = -ENOMEM; 865 goto out_err; 866 } 867 break; 868 869 case Opt_defcontext: 870 if (context || defcontext) { 871 rc = -EINVAL; 872 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 873 goto out_err; 874 } 875 defcontext = match_strdup(&args[0]); 876 if (!defcontext) { 877 rc = -ENOMEM; 878 goto out_err; 879 } 880 break; 881 case Opt_labelsupport: 882 break; 883 default: 884 rc = -EINVAL; 885 printk(KERN_WARNING "SELinux: unknown mount option\n"); 886 goto out_err; 887 888 } 889 } 890 891 rc = -ENOMEM; 892 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC); 893 if (!opts->mnt_opts) 894 goto out_err; 895 896 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC); 897 if (!opts->mnt_opts_flags) { 898 kfree(opts->mnt_opts); 899 goto out_err; 900 } 901 902 if (fscontext) { 903 opts->mnt_opts[num_mnt_opts] = fscontext; 904 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; 905 } 906 if (context) { 907 opts->mnt_opts[num_mnt_opts] = context; 908 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; 909 } 910 if (rootcontext) { 911 opts->mnt_opts[num_mnt_opts] = rootcontext; 912 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; 913 } 914 if (defcontext) { 915 opts->mnt_opts[num_mnt_opts] = defcontext; 916 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; 917 } 918 919 opts->num_mnt_opts = num_mnt_opts; 920 return 0; 921 922out_err: 923 kfree(context); 924 kfree(defcontext); 925 kfree(fscontext); 926 kfree(rootcontext); 927 return rc; 928} 929/* 930 * string mount options parsing and call set the sbsec 931 */ 932static int superblock_doinit(struct super_block *sb, void *data) 933{ 934 int rc = 0; 935 char *options = data; 936 struct security_mnt_opts opts; 937 938 security_init_mnt_opts(&opts); 939 940 if (!data) 941 goto out; 942 943 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); 944 945 rc = selinux_parse_opts_str(options, &opts); 946 if (rc) 947 goto out_err; 948 949out: 950 rc = selinux_set_mnt_opts(sb, &opts); 951 952out_err: 953 security_free_mnt_opts(&opts); 954 return rc; 955} 956 957static void selinux_write_opts(struct seq_file *m, 958 struct security_mnt_opts *opts) 959{ 960 int i; 961 char *prefix; 962 963 for (i = 0; i < opts->num_mnt_opts; i++) { 964 char *has_comma; 965 966 if (opts->mnt_opts[i]) 967 has_comma = strchr(opts->mnt_opts[i], ','); 968 else 969 has_comma = NULL; 970 971 switch (opts->mnt_opts_flags[i]) { 972 case CONTEXT_MNT: 973 prefix = CONTEXT_STR; 974 break; 975 case FSCONTEXT_MNT: 976 prefix = FSCONTEXT_STR; 977 break; 978 case ROOTCONTEXT_MNT: 979 prefix = ROOTCONTEXT_STR; 980 break; 981 case DEFCONTEXT_MNT: 982 prefix = DEFCONTEXT_STR; 983 break; 984 case SE_SBLABELSUPP: 985 seq_putc(m, ','); 986 seq_puts(m, LABELSUPP_STR); 987 continue; 988 default: 989 BUG(); 990 return; 991 }; 992 /* we need a comma before each option */ 993 seq_putc(m, ','); 994 seq_puts(m, prefix); 995 if (has_comma) 996 seq_putc(m, '\"'); 997 seq_puts(m, opts->mnt_opts[i]); 998 if (has_comma) 999 seq_putc(m, '\"'); 1000 } 1001} 1002 1003static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) 1004{ 1005 struct security_mnt_opts opts; 1006 int rc; 1007 1008 rc = selinux_get_mnt_opts(sb, &opts); 1009 if (rc) { 1010 /* before policy load we may get EINVAL, don't show anything */ 1011 if (rc == -EINVAL) 1012 rc = 0; 1013 return rc; 1014 } 1015 1016 selinux_write_opts(m, &opts); 1017 1018 security_free_mnt_opts(&opts); 1019 1020 return rc; 1021} 1022 1023static inline u16 inode_mode_to_security_class(umode_t mode) 1024{ 1025 switch (mode & S_IFMT) { 1026 case S_IFSOCK: 1027 return SECCLASS_SOCK_FILE; 1028 case S_IFLNK: 1029 return SECCLASS_LNK_FILE; 1030 case S_IFREG: 1031 return SECCLASS_FILE; 1032 case S_IFBLK: 1033 return SECCLASS_BLK_FILE; 1034 case S_IFDIR: 1035 return SECCLASS_DIR; 1036 case S_IFCHR: 1037 return SECCLASS_CHR_FILE; 1038 case S_IFIFO: 1039 return SECCLASS_FIFO_FILE; 1040 1041 } 1042 1043 return SECCLASS_FILE; 1044} 1045 1046static inline int default_protocol_stream(int protocol) 1047{ 1048 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); 1049} 1050 1051static inline int default_protocol_dgram(int protocol) 1052{ 1053 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); 1054} 1055 1056static inline u16 socket_type_to_security_class(int family, int type, int protocol) 1057{ 1058 switch (family) { 1059 case PF_UNIX: 1060 switch (type) { 1061 case SOCK_STREAM: 1062 case SOCK_SEQPACKET: 1063 return SECCLASS_UNIX_STREAM_SOCKET; 1064 case SOCK_DGRAM: 1065 return SECCLASS_UNIX_DGRAM_SOCKET; 1066 } 1067 break; 1068 case PF_INET: 1069 case PF_INET6: 1070 switch (type) { 1071 case SOCK_STREAM: 1072 if (default_protocol_stream(protocol)) 1073 return SECCLASS_TCP_SOCKET; 1074 else 1075 return SECCLASS_RAWIP_SOCKET; 1076 case SOCK_DGRAM: 1077 if (default_protocol_dgram(protocol)) 1078 return SECCLASS_UDP_SOCKET; 1079 else 1080 return SECCLASS_RAWIP_SOCKET; 1081 case SOCK_DCCP: 1082 return SECCLASS_DCCP_SOCKET; 1083 default: 1084 return SECCLASS_RAWIP_SOCKET; 1085 } 1086 break; 1087 case PF_NETLINK: 1088 switch (protocol) { 1089 case NETLINK_ROUTE: 1090 return SECCLASS_NETLINK_ROUTE_SOCKET; 1091 case NETLINK_FIREWALL: 1092 return SECCLASS_NETLINK_FIREWALL_SOCKET; 1093 case NETLINK_SOCK_DIAG: 1094 return SECCLASS_NETLINK_TCPDIAG_SOCKET; 1095 case NETLINK_NFLOG: 1096 return SECCLASS_NETLINK_NFLOG_SOCKET; 1097 case NETLINK_XFRM: 1098 return SECCLASS_NETLINK_XFRM_SOCKET; 1099 case NETLINK_SELINUX: 1100 return SECCLASS_NETLINK_SELINUX_SOCKET; 1101 case NETLINK_AUDIT: 1102 return SECCLASS_NETLINK_AUDIT_SOCKET; 1103 case NETLINK_IP6_FW: 1104 return SECCLASS_NETLINK_IP6FW_SOCKET; 1105 case NETLINK_DNRTMSG: 1106 return SECCLASS_NETLINK_DNRT_SOCKET; 1107 case NETLINK_KOBJECT_UEVENT: 1108 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; 1109 default: 1110 return SECCLASS_NETLINK_SOCKET; 1111 } 1112 case PF_PACKET: 1113 return SECCLASS_PACKET_SOCKET; 1114 case PF_KEY: 1115 return SECCLASS_KEY_SOCKET; 1116 case PF_APPLETALK: 1117 return SECCLASS_APPLETALK_SOCKET; 1118 } 1119 1120 return SECCLASS_SOCKET; 1121} 1122 1123#ifdef CONFIG_PROC_FS 1124static int selinux_proc_get_sid(struct dentry *dentry, 1125 u16 tclass, 1126 u32 *sid) 1127{ 1128 int rc; 1129 char *buffer, *path; 1130 1131 buffer = (char *)__get_free_page(GFP_KERNEL); 1132 if (!buffer) 1133 return -ENOMEM; 1134 1135 path = dentry_path_raw(dentry, buffer, PAGE_SIZE); 1136 if (IS_ERR(path)) 1137 rc = PTR_ERR(path); 1138 else { 1139 /* each process gets a /proc/PID/ entry. Strip off the 1140 * PID part to get a valid selinux labeling. 1141 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ 1142 while (path[1] >= '0' && path[1] <= '9') { 1143 path[1] = '/'; 1144 path++; 1145 } 1146 rc = security_genfs_sid("proc", path, tclass, sid); 1147 } 1148 free_page((unsigned long)buffer); 1149 return rc; 1150} 1151#else 1152static int selinux_proc_get_sid(struct dentry *dentry, 1153 u16 tclass, 1154 u32 *sid) 1155{ 1156 return -EINVAL; 1157} 1158#endif 1159 1160/* The inode's security attributes must be initialized before first use. */ 1161static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) 1162{ 1163 struct superblock_security_struct *sbsec = NULL; 1164 struct inode_security_struct *isec = inode->i_security; 1165 u32 sid; 1166 struct dentry *dentry; 1167#define INITCONTEXTLEN 255 1168 char *context = NULL; 1169 unsigned len = 0; 1170 int rc = 0; 1171 1172 if (isec->initialized) 1173 goto out; 1174 1175 mutex_lock(&isec->lock); 1176 if (isec->initialized) 1177 goto out_unlock; 1178 1179 sbsec = inode->i_sb->s_security; 1180 if (!(sbsec->flags & SE_SBINITIALIZED)) { 1181 /* Defer initialization until selinux_complete_init, 1182 after the initial policy is loaded and the security 1183 server is ready to handle calls. */ 1184 spin_lock(&sbsec->isec_lock); 1185 if (list_empty(&isec->list)) 1186 list_add(&isec->list, &sbsec->isec_head); 1187 spin_unlock(&sbsec->isec_lock); 1188 goto out_unlock; 1189 } 1190 1191 switch (sbsec->behavior) { 1192 case SECURITY_FS_USE_XATTR: 1193 if (!inode->i_op->getxattr) { 1194 isec->sid = sbsec->def_sid; 1195 break; 1196 } 1197 1198 /* Need a dentry, since the xattr API requires one. 1199 Life would be simpler if we could just pass the inode. */ 1200 if (opt_dentry) { 1201 /* Called from d_instantiate or d_splice_alias. */ 1202 dentry = dget(opt_dentry); 1203 } else { 1204 /* Called from selinux_complete_init, try to find a dentry. */ 1205 dentry = d_find_alias(inode); 1206 } 1207 if (!dentry) { 1208 /* 1209 * this is can be hit on boot when a file is accessed 1210 * before the policy is loaded. When we load policy we 1211 * may find inodes that have no dentry on the 1212 * sbsec->isec_head list. No reason to complain as these 1213 * will get fixed up the next time we go through 1214 * inode_doinit with a dentry, before these inodes could 1215 * be used again by userspace. 1216 */ 1217 goto out_unlock; 1218 } 1219 1220 len = INITCONTEXTLEN; 1221 context = kmalloc(len+1, GFP_NOFS); 1222 if (!context) { 1223 rc = -ENOMEM; 1224 dput(dentry); 1225 goto out_unlock; 1226 } 1227 context[len] = '\0'; 1228 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1229 context, len); 1230 if (rc == -ERANGE) { 1231 kfree(context); 1232 1233 /* Need a larger buffer. Query for the right size. */ 1234 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1235 NULL, 0); 1236 if (rc < 0) { 1237 dput(dentry); 1238 goto out_unlock; 1239 } 1240 len = rc; 1241 context = kmalloc(len+1, GFP_NOFS); 1242 if (!context) { 1243 rc = -ENOMEM; 1244 dput(dentry); 1245 goto out_unlock; 1246 } 1247 context[len] = '\0'; 1248 rc = inode->i_op->getxattr(dentry, 1249 XATTR_NAME_SELINUX, 1250 context, len); 1251 } 1252 dput(dentry); 1253 if (rc < 0) { 1254 if (rc != -ENODATA) { 1255 printk(KERN_WARNING "SELinux: %s: getxattr returned " 1256 "%d for dev=%s ino=%ld\n", __func__, 1257 -rc, inode->i_sb->s_id, inode->i_ino); 1258 kfree(context); 1259 goto out_unlock; 1260 } 1261 /* Map ENODATA to the default file SID */ 1262 sid = sbsec->def_sid; 1263 rc = 0; 1264 } else { 1265 rc = security_context_to_sid_default(context, rc, &sid, 1266 sbsec->def_sid, 1267 GFP_NOFS); 1268 if (rc) { 1269 char *dev = inode->i_sb->s_id; 1270 unsigned long ino = inode->i_ino; 1271 1272 if (rc == -EINVAL) { 1273 if (printk_ratelimit()) 1274 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " 1275 "context=%s. This indicates you may need to relabel the inode or the " 1276 "filesystem in question.\n", ino, dev, context); 1277 } else { 1278 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " 1279 "returned %d for dev=%s ino=%ld\n", 1280 __func__, context, -rc, dev, ino); 1281 } 1282 kfree(context); 1283 /* Leave with the unlabeled SID */ 1284 rc = 0; 1285 break; 1286 } 1287 } 1288 kfree(context); 1289 isec->sid = sid; 1290 break; 1291 case SECURITY_FS_USE_TASK: 1292 isec->sid = isec->task_sid; 1293 break; 1294 case SECURITY_FS_USE_TRANS: 1295 /* Default to the fs SID. */ 1296 isec->sid = sbsec->sid; 1297 1298 /* Try to obtain a transition SID. */ 1299 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1300 rc = security_transition_sid(isec->task_sid, sbsec->sid, 1301 isec->sclass, NULL, &sid); 1302 if (rc) 1303 goto out_unlock; 1304 isec->sid = sid; 1305 break; 1306 case SECURITY_FS_USE_MNTPOINT: 1307 isec->sid = sbsec->mntpoint_sid; 1308 break; 1309 default: 1310 /* Default to the fs superblock SID. */ 1311 isec->sid = sbsec->sid; 1312 1313 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) { 1314 if (opt_dentry) { 1315 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1316 rc = selinux_proc_get_sid(opt_dentry, 1317 isec->sclass, 1318 &sid); 1319 if (rc) 1320 goto out_unlock; 1321 isec->sid = sid; 1322 } 1323 } 1324 break; 1325 } 1326 1327 isec->initialized = 1; 1328 1329out_unlock: 1330 mutex_unlock(&isec->lock); 1331out: 1332 if (isec->sclass == SECCLASS_FILE) 1333 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1334 return rc; 1335} 1336 1337/* Convert a Linux signal to an access vector. */ 1338static inline u32 signal_to_av(int sig) 1339{ 1340 u32 perm = 0; 1341 1342 switch (sig) { 1343 case SIGCHLD: 1344 /* Commonly granted from child to parent. */ 1345 perm = PROCESS__SIGCHLD; 1346 break; 1347 case SIGKILL: 1348 /* Cannot be caught or ignored */ 1349 perm = PROCESS__SIGKILL; 1350 break; 1351 case SIGSTOP: 1352 /* Cannot be caught or ignored */ 1353 perm = PROCESS__SIGSTOP; 1354 break; 1355 default: 1356 /* All other signals. */ 1357 perm = PROCESS__SIGNAL; 1358 break; 1359 } 1360 1361 return perm; 1362} 1363 1364/* 1365 * Check permission between a pair of credentials 1366 * fork check, ptrace check, etc. 1367 */ 1368static int cred_has_perm(const struct cred *actor, 1369 const struct cred *target, 1370 u32 perms) 1371{ 1372 u32 asid = cred_sid(actor), tsid = cred_sid(target); 1373 1374 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL); 1375} 1376 1377/* 1378 * Check permission between a pair of tasks, e.g. signal checks, 1379 * fork check, ptrace check, etc. 1380 * tsk1 is the actor and tsk2 is the target 1381 * - this uses the default subjective creds of tsk1 1382 */ 1383static int task_has_perm(const struct task_struct *tsk1, 1384 const struct task_struct *tsk2, 1385 u32 perms) 1386{ 1387 const struct task_security_struct *__tsec1, *__tsec2; 1388 u32 sid1, sid2; 1389 1390 rcu_read_lock(); 1391 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid; 1392 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid; 1393 rcu_read_unlock(); 1394 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL); 1395} 1396 1397/* 1398 * Check permission between current and another task, e.g. signal checks, 1399 * fork check, ptrace check, etc. 1400 * current is the actor and tsk2 is the target 1401 * - this uses current's subjective creds 1402 */ 1403static int current_has_perm(const struct task_struct *tsk, 1404 u32 perms) 1405{ 1406 u32 sid, tsid; 1407 1408 sid = current_sid(); 1409 tsid = task_sid(tsk); 1410 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL); 1411} 1412 1413#if CAP_LAST_CAP > 63 1414#error Fix SELinux to handle capabilities > 63. 1415#endif 1416 1417/* Check whether a task is allowed to use a capability. */ 1418static int task_has_capability(struct task_struct *tsk, 1419 const struct cred *cred, 1420 int cap, int audit) 1421{ 1422 struct common_audit_data ad; 1423 struct av_decision avd; 1424 u16 sclass; 1425 u32 sid = cred_sid(cred); 1426 u32 av = CAP_TO_MASK(cap); 1427 int rc; 1428 1429 COMMON_AUDIT_DATA_INIT(&ad, CAP); 1430 ad.tsk = tsk; 1431 ad.u.cap = cap; 1432 1433 switch (CAP_TO_INDEX(cap)) { 1434 case 0: 1435 sclass = SECCLASS_CAPABILITY; 1436 break; 1437 case 1: 1438 sclass = SECCLASS_CAPABILITY2; 1439 break; 1440 default: 1441 printk(KERN_ERR 1442 "SELinux: out of range capability %d\n", cap); 1443 BUG(); 1444 return -EINVAL; 1445 } 1446 1447 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); 1448 if (audit == SECURITY_CAP_AUDIT) { 1449 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); 1450 if (rc2) 1451 return rc2; 1452 } 1453 return rc; 1454} 1455 1456/* Check whether a task is allowed to use a system operation. */ 1457static int task_has_system(struct task_struct *tsk, 1458 u32 perms) 1459{ 1460 u32 sid = task_sid(tsk); 1461 1462 return avc_has_perm(sid, SECINITSID_KERNEL, 1463 SECCLASS_SYSTEM, perms, NULL); 1464} 1465 1466/* Check whether a task has a particular permission to an inode. 1467 The 'adp' parameter is optional and allows other audit 1468 data to be passed (e.g. the dentry). */ 1469static int inode_has_perm(const struct cred *cred, 1470 struct inode *inode, 1471 u32 perms, 1472 struct common_audit_data *adp, 1473 unsigned flags) 1474{ 1475 struct inode_security_struct *isec; 1476 u32 sid; 1477 1478 validate_creds(cred); 1479 1480 if (unlikely(IS_PRIVATE(inode))) 1481 return 0; 1482 1483 sid = cred_sid(cred); 1484 isec = inode->i_security; 1485 1486 return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags); 1487} 1488 1489static int inode_has_perm_noadp(const struct cred *cred, 1490 struct inode *inode, 1491 u32 perms, 1492 unsigned flags) 1493{ 1494 struct common_audit_data ad; 1495 1496 COMMON_AUDIT_DATA_INIT(&ad, INODE); 1497 ad.u.inode = inode; 1498 return inode_has_perm(cred, inode, perms, &ad, flags); 1499} 1500 1501/* Same as inode_has_perm, but pass explicit audit data containing 1502 the dentry to help the auditing code to more easily generate the 1503 pathname if needed. */ 1504static inline int dentry_has_perm(const struct cred *cred, 1505 struct dentry *dentry, 1506 u32 av) 1507{ 1508 struct inode *inode = dentry->d_inode; 1509 struct common_audit_data ad; 1510 1511 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1512 ad.u.dentry = dentry; 1513 return inode_has_perm(cred, inode, av, &ad, 0); 1514} 1515 1516/* Same as inode_has_perm, but pass explicit audit data containing 1517 the path to help the auditing code to more easily generate the 1518 pathname if needed. */ 1519static inline int path_has_perm(const struct cred *cred, 1520 struct path *path, 1521 u32 av) 1522{ 1523 struct inode *inode = path->dentry->d_inode; 1524 struct common_audit_data ad; 1525 1526 COMMON_AUDIT_DATA_INIT(&ad, PATH); 1527 ad.u.path = *path; 1528 return inode_has_perm(cred, inode, av, &ad, 0); 1529} 1530 1531/* Check whether a task can use an open file descriptor to 1532 access an inode in a given way. Check access to the 1533 descriptor itself, and then use dentry_has_perm to 1534 check a particular permission to the file. 1535 Access to the descriptor is implicitly granted if it 1536 has the same SID as the process. If av is zero, then 1537 access to the file is not checked, e.g. for cases 1538 where only the descriptor is affected like seek. */ 1539static int file_has_perm(const struct cred *cred, 1540 struct file *file, 1541 u32 av) 1542{ 1543 struct file_security_struct *fsec = file->f_security; 1544 struct inode *inode = file->f_path.dentry->d_inode; 1545 struct common_audit_data ad; 1546 u32 sid = cred_sid(cred); 1547 int rc; 1548 1549 COMMON_AUDIT_DATA_INIT(&ad, PATH); 1550 ad.u.path = file->f_path; 1551 1552 if (sid != fsec->sid) { 1553 rc = avc_has_perm(sid, fsec->sid, 1554 SECCLASS_FD, 1555 FD__USE, 1556 &ad); 1557 if (rc) 1558 goto out; 1559 } 1560 1561 /* av is zero if only checking access to the descriptor. */ 1562 rc = 0; 1563 if (av) 1564 rc = inode_has_perm(cred, inode, av, &ad, 0); 1565 1566out: 1567 return rc; 1568} 1569 1570/* Check whether a task can create a file. */ 1571static int may_create(struct inode *dir, 1572 struct dentry *dentry, 1573 u16 tclass) 1574{ 1575 const struct task_security_struct *tsec = current_security(); 1576 struct inode_security_struct *dsec; 1577 struct superblock_security_struct *sbsec; 1578 u32 sid, newsid; 1579 struct common_audit_data ad; 1580 int rc; 1581 1582 dsec = dir->i_security; 1583 sbsec = dir->i_sb->s_security; 1584 1585 sid = tsec->sid; 1586 newsid = tsec->create_sid; 1587 1588 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1589 ad.u.dentry = dentry; 1590 1591 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, 1592 DIR__ADD_NAME | DIR__SEARCH, 1593 &ad); 1594 if (rc) 1595 return rc; 1596 1597 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 1598 rc = security_transition_sid(sid, dsec->sid, tclass, 1599 &dentry->d_name, &newsid); 1600 if (rc) 1601 return rc; 1602 } 1603 1604 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); 1605 if (rc) 1606 return rc; 1607 1608 return avc_has_perm(newsid, sbsec->sid, 1609 SECCLASS_FILESYSTEM, 1610 FILESYSTEM__ASSOCIATE, &ad); 1611} 1612 1613/* Check whether a task can create a key. */ 1614static int may_create_key(u32 ksid, 1615 struct task_struct *ctx) 1616{ 1617 u32 sid = task_sid(ctx); 1618 1619 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); 1620} 1621 1622#define MAY_LINK 0 1623#define MAY_UNLINK 1 1624#define MAY_RMDIR 2 1625 1626/* Check whether a task can link, unlink, or rmdir a file/directory. */ 1627static int may_link(struct inode *dir, 1628 struct dentry *dentry, 1629 int kind) 1630 1631{ 1632 struct inode_security_struct *dsec, *isec; 1633 struct common_audit_data ad; 1634 u32 sid = current_sid(); 1635 u32 av; 1636 int rc; 1637 1638 dsec = dir->i_security; 1639 isec = dentry->d_inode->i_security; 1640 1641 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1642 ad.u.dentry = dentry; 1643 1644 av = DIR__SEARCH; 1645 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); 1646 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); 1647 if (rc) 1648 return rc; 1649 1650 switch (kind) { 1651 case MAY_LINK: 1652 av = FILE__LINK; 1653 break; 1654 case MAY_UNLINK: 1655 av = FILE__UNLINK; 1656 break; 1657 case MAY_RMDIR: 1658 av = DIR__RMDIR; 1659 break; 1660 default: 1661 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", 1662 __func__, kind); 1663 return 0; 1664 } 1665 1666 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); 1667 return rc; 1668} 1669 1670static inline int may_rename(struct inode *old_dir, 1671 struct dentry *old_dentry, 1672 struct inode *new_dir, 1673 struct dentry *new_dentry) 1674{ 1675 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; 1676 struct common_audit_data ad; 1677 u32 sid = current_sid(); 1678 u32 av; 1679 int old_is_dir, new_is_dir; 1680 int rc; 1681 1682 old_dsec = old_dir->i_security; 1683 old_isec = old_dentry->d_inode->i_security; 1684 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); 1685 new_dsec = new_dir->i_security; 1686 1687 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1688 1689 ad.u.dentry = old_dentry; 1690 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, 1691 DIR__REMOVE_NAME | DIR__SEARCH, &ad); 1692 if (rc) 1693 return rc; 1694 rc = avc_has_perm(sid, old_isec->sid, 1695 old_isec->sclass, FILE__RENAME, &ad); 1696 if (rc) 1697 return rc; 1698 if (old_is_dir && new_dir != old_dir) { 1699 rc = avc_has_perm(sid, old_isec->sid, 1700 old_isec->sclass, DIR__REPARENT, &ad); 1701 if (rc) 1702 return rc; 1703 } 1704 1705 ad.u.dentry = new_dentry; 1706 av = DIR__ADD_NAME | DIR__SEARCH; 1707 if (new_dentry->d_inode) 1708 av |= DIR__REMOVE_NAME; 1709 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); 1710 if (rc) 1711 return rc; 1712 if (new_dentry->d_inode) { 1713 new_isec = new_dentry->d_inode->i_security; 1714 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); 1715 rc = avc_has_perm(sid, new_isec->sid, 1716 new_isec->sclass, 1717 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); 1718 if (rc) 1719 return rc; 1720 } 1721 1722 return 0; 1723} 1724 1725/* Check whether a task can perform a filesystem operation. */ 1726static int superblock_has_perm(const struct cred *cred, 1727 struct super_block *sb, 1728 u32 perms, 1729 struct common_audit_data *ad) 1730{ 1731 struct superblock_security_struct *sbsec; 1732 u32 sid = cred_sid(cred); 1733 1734 sbsec = sb->s_security; 1735 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); 1736} 1737 1738/* Convert a Linux mode and permission mask to an access vector. */ 1739static inline u32 file_mask_to_av(int mode, int mask) 1740{ 1741 u32 av = 0; 1742 1743 if ((mode & S_IFMT) != S_IFDIR) { 1744 if (mask & MAY_EXEC) 1745 av |= FILE__EXECUTE; 1746 if (mask & MAY_READ) 1747 av |= FILE__READ; 1748 1749 if (mask & MAY_APPEND) 1750 av |= FILE__APPEND; 1751 else if (mask & MAY_WRITE) 1752 av |= FILE__WRITE; 1753 1754 } else { 1755 if (mask & MAY_EXEC) 1756 av |= DIR__SEARCH; 1757 if (mask & MAY_WRITE) 1758 av |= DIR__WRITE; 1759 if (mask & MAY_READ) 1760 av |= DIR__READ; 1761 } 1762 1763 return av; 1764} 1765 1766/* Convert a Linux file to an access vector. */ 1767static inline u32 file_to_av(struct file *file) 1768{ 1769 u32 av = 0; 1770 1771 if (file->f_mode & FMODE_READ) 1772 av |= FILE__READ; 1773 if (file->f_mode & FMODE_WRITE) { 1774 if (file->f_flags & O_APPEND) 1775 av |= FILE__APPEND; 1776 else 1777 av |= FILE__WRITE; 1778 } 1779 if (!av) { 1780 /* 1781 * Special file opened with flags 3 for ioctl-only use. 1782 */ 1783 av = FILE__IOCTL; 1784 } 1785 1786 return av; 1787} 1788 1789/* 1790 * Convert a file to an access vector and include the correct open 1791 * open permission. 1792 */ 1793static inline u32 open_file_to_av(struct file *file) 1794{ 1795 u32 av = file_to_av(file); 1796 1797 if (selinux_policycap_openperm) 1798 av |= FILE__OPEN; 1799 1800 return av; 1801} 1802 1803/* Hook functions begin here. */ 1804 1805static int selinux_ptrace_access_check(struct task_struct *child, 1806 unsigned int mode) 1807{ 1808 int rc; 1809 1810 rc = cap_ptrace_access_check(child, mode); 1811 if (rc) 1812 return rc; 1813 1814 if (mode == PTRACE_MODE_READ) { 1815 u32 sid = current_sid(); 1816 u32 csid = task_sid(child); 1817 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); 1818 } 1819 1820 return current_has_perm(child, PROCESS__PTRACE); 1821} 1822 1823static int selinux_ptrace_traceme(struct task_struct *parent) 1824{ 1825 int rc; 1826 1827 rc = cap_ptrace_traceme(parent); 1828 if (rc) 1829 return rc; 1830 1831 return task_has_perm(parent, current, PROCESS__PTRACE); 1832} 1833 1834static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, 1835 kernel_cap_t *inheritable, kernel_cap_t *permitted) 1836{ 1837 int error; 1838 1839 error = current_has_perm(target, PROCESS__GETCAP); 1840 if (error) 1841 return error; 1842 1843 return cap_capget(target, effective, inheritable, permitted); 1844} 1845 1846static int selinux_capset(struct cred *new, const struct cred *old, 1847 const kernel_cap_t *effective, 1848 const kernel_cap_t *inheritable, 1849 const kernel_cap_t *permitted) 1850{ 1851 int error; 1852 1853 error = cap_capset(new, old, 1854 effective, inheritable, permitted); 1855 if (error) 1856 return error; 1857 1858 return cred_has_perm(old, new, PROCESS__SETCAP); 1859} 1860 1861/* 1862 * (This comment used to live with the selinux_task_setuid hook, 1863 * which was removed). 1864 * 1865 * Since setuid only affects the current process, and since the SELinux 1866 * controls are not based on the Linux identity attributes, SELinux does not 1867 * need to control this operation. However, SELinux does control the use of 1868 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. 1869 */ 1870 1871static int selinux_capable(struct task_struct *tsk, const struct cred *cred, 1872 struct user_namespace *ns, int cap, int audit) 1873{ 1874 int rc; 1875 1876 rc = cap_capable(tsk, cred, ns, cap, audit); 1877 if (rc) 1878 return rc; 1879 1880 return task_has_capability(tsk, cred, cap, audit); 1881} 1882 1883static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) 1884{ 1885 const struct cred *cred = current_cred(); 1886 int rc = 0; 1887 1888 if (!sb) 1889 return 0; 1890 1891 switch (cmds) { 1892 case Q_SYNC: 1893 case Q_QUOTAON: 1894 case Q_QUOTAOFF: 1895 case Q_SETINFO: 1896 case Q_SETQUOTA: 1897 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); 1898 break; 1899 case Q_GETFMT: 1900 case Q_GETINFO: 1901 case Q_GETQUOTA: 1902 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); 1903 break; 1904 default: 1905 rc = 0; /* let the kernel handle invalid cmds */ 1906 break; 1907 } 1908 return rc; 1909} 1910 1911static int selinux_quota_on(struct dentry *dentry) 1912{ 1913 const struct cred *cred = current_cred(); 1914 1915 return dentry_has_perm(cred, dentry, FILE__QUOTAON); 1916} 1917 1918static int selinux_syslog(int type) 1919{ 1920 int rc; 1921 1922 switch (type) { 1923 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ 1924 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ 1925 rc = task_has_system(current, SYSTEM__SYSLOG_READ); 1926 break; 1927 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ 1928 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ 1929 /* Set level of messages printed to console */ 1930 case SYSLOG_ACTION_CONSOLE_LEVEL: 1931 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE); 1932 break; 1933 case SYSLOG_ACTION_CLOSE: /* Close log */ 1934 case SYSLOG_ACTION_OPEN: /* Open log */ 1935 case SYSLOG_ACTION_READ: /* Read from log */ 1936 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */ 1937 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */ 1938 default: 1939 rc = task_has_system(current, SYSTEM__SYSLOG_MOD); 1940 break; 1941 } 1942 return rc; 1943} 1944 1945/* 1946 * Check that a process has enough memory to allocate a new virtual 1947 * mapping. 0 means there is enough memory for the allocation to 1948 * succeed and -ENOMEM implies there is not. 1949 * 1950 * Do not audit the selinux permission check, as this is applied to all 1951 * processes that allocate mappings. 1952 */ 1953static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) 1954{ 1955 int rc, cap_sys_admin = 0; 1956 1957 rc = selinux_capable(current, current_cred(), 1958 &init_user_ns, CAP_SYS_ADMIN, 1959 SECURITY_CAP_NOAUDIT); 1960 if (rc == 0) 1961 cap_sys_admin = 1; 1962 1963 return __vm_enough_memory(mm, pages, cap_sys_admin); 1964} 1965 1966/* binprm security operations */ 1967 1968static int selinux_bprm_set_creds(struct linux_binprm *bprm) 1969{ 1970 const struct task_security_struct *old_tsec; 1971 struct task_security_struct *new_tsec; 1972 struct inode_security_struct *isec; 1973 struct common_audit_data ad; 1974 struct inode *inode = bprm->file->f_path.dentry->d_inode; 1975 int rc; 1976 1977 rc = cap_bprm_set_creds(bprm); 1978 if (rc) 1979 return rc; 1980 1981 /* SELinux context only depends on initial program or script and not 1982 * the script interpreter */ 1983 if (bprm->cred_prepared) 1984 return 0; 1985 1986 old_tsec = current_security(); 1987 new_tsec = bprm->cred->security; 1988 isec = inode->i_security; 1989 1990 /* Default to the current task SID. */ 1991 new_tsec->sid = old_tsec->sid; 1992 new_tsec->osid = old_tsec->sid; 1993 1994 /* Reset fs, key, and sock SIDs on execve. */ 1995 new_tsec->create_sid = 0; 1996 new_tsec->keycreate_sid = 0; 1997 new_tsec->sockcreate_sid = 0; 1998 1999 if (old_tsec->exec_sid) { 2000 new_tsec->sid = old_tsec->exec_sid; 2001 /* Reset exec SID on execve. */ 2002 new_tsec->exec_sid = 0; 2003 } else { 2004 /* Check for a default transition on this program. */ 2005 rc = security_transition_sid(old_tsec->sid, isec->sid, 2006 SECCLASS_PROCESS, NULL, 2007 &new_tsec->sid); 2008 if (rc) 2009 return rc; 2010 } 2011 2012 COMMON_AUDIT_DATA_INIT(&ad, PATH); 2013 ad.u.path = bprm->file->f_path; 2014 2015 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) 2016 new_tsec->sid = old_tsec->sid; 2017 2018 if (new_tsec->sid == old_tsec->sid) { 2019 rc = avc_has_perm(old_tsec->sid, isec->sid, 2020 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); 2021 if (rc) 2022 return rc; 2023 } else { 2024 /* Check permissions for the transition. */ 2025 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2026 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); 2027 if (rc) 2028 return rc; 2029 2030 rc = avc_has_perm(new_tsec->sid, isec->sid, 2031 SECCLASS_FILE, FILE__ENTRYPOINT, &ad); 2032 if (rc) 2033 return rc; 2034 2035 /* Check for shared state */ 2036 if (bprm->unsafe & LSM_UNSAFE_SHARE) { 2037 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2038 SECCLASS_PROCESS, PROCESS__SHARE, 2039 NULL); 2040 if (rc) 2041 return -EPERM; 2042 } 2043 2044 /* Make sure that anyone attempting to ptrace over a task that 2045 * changes its SID has the appropriate permit */ 2046 if (bprm->unsafe & 2047 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { 2048 struct task_struct *tracer; 2049 struct task_security_struct *sec; 2050 u32 ptsid = 0; 2051 2052 rcu_read_lock(); 2053 tracer = ptrace_parent(current); 2054 if (likely(tracer != NULL)) { 2055 sec = __task_cred(tracer)->security; 2056 ptsid = sec->sid; 2057 } 2058 rcu_read_unlock(); 2059 2060 if (ptsid != 0) { 2061 rc = avc_has_perm(ptsid, new_tsec->sid, 2062 SECCLASS_PROCESS, 2063 PROCESS__PTRACE, NULL); 2064 if (rc) 2065 return -EPERM; 2066 } 2067 } 2068 2069 /* Clear any possibly unsafe personality bits on exec: */ 2070 bprm->per_clear |= PER_CLEAR_ON_SETID; 2071 } 2072 2073 return 0; 2074} 2075 2076static int selinux_bprm_secureexec(struct linux_binprm *bprm) 2077{ 2078 const struct task_security_struct *tsec = current_security(); 2079 u32 sid, osid; 2080 int atsecure = 0; 2081 2082 sid = tsec->sid; 2083 osid = tsec->osid; 2084 2085 if (osid != sid) { 2086 /* Enable secure mode for SIDs transitions unless 2087 the noatsecure permission is granted between 2088 the two SIDs, i.e. ahp returns 0. */ 2089 atsecure = avc_has_perm(osid, sid, 2090 SECCLASS_PROCESS, 2091 PROCESS__NOATSECURE, NULL); 2092 } 2093 2094 return (atsecure || cap_bprm_secureexec(bprm)); 2095} 2096 2097/* Derived from fs/exec.c:flush_old_files. */ 2098static inline void flush_unauthorized_files(const struct cred *cred, 2099 struct files_struct *files) 2100{ 2101 struct common_audit_data ad; 2102 struct file *file, *devnull = NULL; 2103 struct tty_struct *tty; 2104 struct fdtable *fdt; 2105 long j = -1; 2106 int drop_tty = 0; 2107 2108 tty = get_current_tty(); 2109 if (tty) { 2110 spin_lock(&tty_files_lock); 2111 if (!list_empty(&tty->tty_files)) { 2112 struct tty_file_private *file_priv; 2113 struct inode *inode; 2114 2115 /* Revalidate access to controlling tty. 2116 Use inode_has_perm on the tty inode directly rather 2117 than using file_has_perm, as this particular open 2118 file may belong to another process and we are only 2119 interested in the inode-based check here. */ 2120 file_priv = list_first_entry(&tty->tty_files, 2121 struct tty_file_private, list); 2122 file = file_priv->file; 2123 inode = file->f_path.dentry->d_inode; 2124 if (inode_has_perm_noadp(cred, inode, 2125 FILE__READ | FILE__WRITE, 0)) { 2126 drop_tty = 1; 2127 } 2128 } 2129 spin_unlock(&tty_files_lock); 2130 tty_kref_put(tty); 2131 } 2132 /* Reset controlling tty. */ 2133 if (drop_tty) 2134 no_tty(); 2135 2136 /* Revalidate access to inherited open files. */ 2137 2138 COMMON_AUDIT_DATA_INIT(&ad, INODE); 2139 2140 spin_lock(&files->file_lock); 2141 for (;;) { 2142 unsigned long set, i; 2143 int fd; 2144 2145 j++; 2146 i = j * __NFDBITS; 2147 fdt = files_fdtable(files); 2148 if (i >= fdt->max_fds) 2149 break; 2150 set = fdt->open_fds->fds_bits[j]; 2151 if (!set) 2152 continue; 2153 spin_unlock(&files->file_lock); 2154 for ( ; set ; i++, set >>= 1) { 2155 if (set & 1) { 2156 file = fget(i); 2157 if (!file) 2158 continue; 2159 if (file_has_perm(cred, 2160 file, 2161 file_to_av(file))) { 2162 sys_close(i); 2163 fd = get_unused_fd(); 2164 if (fd != i) { 2165 if (fd >= 0) 2166 put_unused_fd(fd); 2167 fput(file); 2168 continue; 2169 } 2170 if (devnull) { 2171 get_file(devnull); 2172 } else { 2173 devnull = dentry_open( 2174 dget(selinux_null), 2175 mntget(selinuxfs_mount), 2176 O_RDWR, cred); 2177 if (IS_ERR(devnull)) { 2178 devnull = NULL; 2179 put_unused_fd(fd); 2180 fput(file); 2181 continue; 2182 } 2183 } 2184 fd_install(fd, devnull); 2185 } 2186 fput(file); 2187 } 2188 } 2189 spin_lock(&files->file_lock); 2190 2191 } 2192 spin_unlock(&files->file_lock); 2193} 2194 2195/* 2196 * Prepare a process for imminent new credential changes due to exec 2197 */ 2198static void selinux_bprm_committing_creds(struct linux_binprm *bprm) 2199{ 2200 struct task_security_struct *new_tsec; 2201 struct rlimit *rlim, *initrlim; 2202 int rc, i; 2203 2204 new_tsec = bprm->cred->security; 2205 if (new_tsec->sid == new_tsec->osid) 2206 return; 2207 2208 /* Close files for which the new task SID is not authorized. */ 2209 flush_unauthorized_files(bprm->cred, current->files); 2210 2211 /* Always clear parent death signal on SID transitions. */ 2212 current->pdeath_signal = 0; 2213 2214 /* Check whether the new SID can inherit resource limits from the old 2215 * SID. If not, reset all soft limits to the lower of the current 2216 * task's hard limit and the init task's soft limit. 2217 * 2218 * Note that the setting of hard limits (even to lower them) can be 2219 * controlled by the setrlimit check. The inclusion of the init task's 2220 * soft limit into the computation is to avoid resetting soft limits 2221 * higher than the default soft limit for cases where the default is 2222 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. 2223 */ 2224 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, 2225 PROCESS__RLIMITINH, NULL); 2226 if (rc) { 2227 /* protect against do_prlimit() */ 2228 task_lock(current); 2229 for (i = 0; i < RLIM_NLIMITS; i++) { 2230 rlim = current->signal->rlim + i; 2231 initrlim = init_task.signal->rlim + i; 2232 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); 2233 } 2234 task_unlock(current); 2235 update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); 2236 } 2237} 2238 2239/* 2240 * Clean up the process immediately after the installation of new credentials 2241 * due to exec 2242 */ 2243static void selinux_bprm_committed_creds(struct linux_binprm *bprm) 2244{ 2245 const struct task_security_struct *tsec = current_security(); 2246 struct itimerval itimer; 2247 u32 osid, sid; 2248 int rc, i; 2249 2250 osid = tsec->osid; 2251 sid = tsec->sid; 2252 2253 if (sid == osid) 2254 return; 2255 2256 /* Check whether the new SID can inherit signal state from the old SID. 2257 * If not, clear itimers to avoid subsequent signal generation and 2258 * flush and unblock signals. 2259 * 2260 * This must occur _after_ the task SID has been updated so that any 2261 * kill done after the flush will be checked against the new SID. 2262 */ 2263 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); 2264 if (rc) { 2265 memset(&itimer, 0, sizeof itimer); 2266 for (i = 0; i < 3; i++) 2267 do_setitimer(i, &itimer, NULL); 2268 spin_lock_irq(¤t->sighand->siglock); 2269 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { 2270 __flush_signals(current); 2271 flush_signal_handlers(current, 1); 2272 sigemptyset(¤t->blocked); 2273 } 2274 spin_unlock_irq(¤t->sighand->siglock); 2275 } 2276 2277 /* Wake up the parent if it is waiting so that it can recheck 2278 * wait permission to the new task SID. */ 2279 read_lock(&tasklist_lock); 2280 __wake_up_parent(current, current->real_parent); 2281 read_unlock(&tasklist_lock); 2282} 2283 2284/* superblock security operations */ 2285 2286static int selinux_sb_alloc_security(struct super_block *sb) 2287{ 2288 return superblock_alloc_security(sb); 2289} 2290 2291static void selinux_sb_free_security(struct super_block *sb) 2292{ 2293 superblock_free_security(sb); 2294} 2295 2296static inline int match_prefix(char *prefix, int plen, char *option, int olen) 2297{ 2298 if (plen > olen) 2299 return 0; 2300 2301 return !memcmp(prefix, option, plen); 2302} 2303 2304static inline int selinux_option(char *option, int len) 2305{ 2306 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || 2307 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || 2308 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || 2309 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || 2310 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); 2311} 2312 2313static inline void take_option(char **to, char *from, int *first, int len) 2314{ 2315 if (!*first) { 2316 **to = ','; 2317 *to += 1; 2318 } else 2319 *first = 0; 2320 memcpy(*to, from, len); 2321 *to += len; 2322} 2323 2324static inline void take_selinux_option(char **to, char *from, int *first, 2325 int len) 2326{ 2327 int current_size = 0; 2328 2329 if (!*first) { 2330 **to = '|'; 2331 *to += 1; 2332 } else 2333 *first = 0; 2334 2335 while (current_size < len) { 2336 if (*from != '"') { 2337 **to = *from; 2338 *to += 1; 2339 } 2340 from += 1; 2341 current_size += 1; 2342 } 2343} 2344 2345static int selinux_sb_copy_data(char *orig, char *copy) 2346{ 2347 int fnosec, fsec, rc = 0; 2348 char *in_save, *in_curr, *in_end; 2349 char *sec_curr, *nosec_save, *nosec; 2350 int open_quote = 0; 2351 2352 in_curr = orig; 2353 sec_curr = copy; 2354 2355 nosec = (char *)get_zeroed_page(GFP_KERNEL); 2356 if (!nosec) { 2357 rc = -ENOMEM; 2358 goto out; 2359 } 2360 2361 nosec_save = nosec; 2362 fnosec = fsec = 1; 2363 in_save = in_end = orig; 2364 2365 do { 2366 if (*in_end == '"') 2367 open_quote = !open_quote; 2368 if ((*in_end == ',' && open_quote == 0) || 2369 *in_end == '\0') { 2370 int len = in_end - in_curr; 2371 2372 if (selinux_option(in_curr, len)) 2373 take_selinux_option(&sec_curr, in_curr, &fsec, len); 2374 else 2375 take_option(&nosec, in_curr, &fnosec, len); 2376 2377 in_curr = in_end + 1; 2378 } 2379 } while (*in_end++); 2380 2381 strcpy(in_save, nosec_save); 2382 free_page((unsigned long)nosec_save); 2383out: 2384 return rc; 2385} 2386 2387static int selinux_sb_remount(struct super_block *sb, void *data) 2388{ 2389 int rc, i, *flags; 2390 struct security_mnt_opts opts; 2391 char *secdata, **mount_options; 2392 struct superblock_security_struct *sbsec = sb->s_security; 2393 2394 if (!(sbsec->flags & SE_SBINITIALIZED)) 2395 return 0; 2396 2397 if (!data) 2398 return 0; 2399 2400 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 2401 return 0; 2402 2403 security_init_mnt_opts(&opts); 2404 secdata = alloc_secdata(); 2405 if (!secdata) 2406 return -ENOMEM; 2407 rc = selinux_sb_copy_data(data, secdata); 2408 if (rc) 2409 goto out_free_secdata; 2410 2411 rc = selinux_parse_opts_str(secdata, &opts); 2412 if (rc) 2413 goto out_free_secdata; 2414 2415 mount_options = opts.mnt_opts; 2416 flags = opts.mnt_opts_flags; 2417 2418 for (i = 0; i < opts.num_mnt_opts; i++) { 2419 u32 sid; 2420 size_t len; 2421 2422 if (flags[i] == SE_SBLABELSUPP) 2423 continue; 2424 len = strlen(mount_options[i]); 2425 rc = security_context_to_sid(mount_options[i], len, &sid); 2426 if (rc) { 2427 printk(KERN_WARNING "SELinux: security_context_to_sid" 2428 "(%s) failed for (dev %s, type %s) errno=%d\n", 2429 mount_options[i], sb->s_id, sb->s_type->name, rc); 2430 goto out_free_opts; 2431 } 2432 rc = -EINVAL; 2433 switch (flags[i]) { 2434 case FSCONTEXT_MNT: 2435 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) 2436 goto out_bad_option; 2437 break; 2438 case CONTEXT_MNT: 2439 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) 2440 goto out_bad_option; 2441 break; 2442 case ROOTCONTEXT_MNT: { 2443 struct inode_security_struct *root_isec; 2444 root_isec = sb->s_root->d_inode->i_security; 2445 2446 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) 2447 goto out_bad_option; 2448 break; 2449 } 2450 case DEFCONTEXT_MNT: 2451 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) 2452 goto out_bad_option; 2453 break; 2454 default: 2455 goto out_free_opts; 2456 } 2457 } 2458 2459 rc = 0; 2460out_free_opts: 2461 security_free_mnt_opts(&opts); 2462out_free_secdata: 2463 free_secdata(secdata); 2464 return rc; 2465out_bad_option: 2466 printk(KERN_WARNING "SELinux: unable to change security options " 2467 "during remount (dev %s, type=%s)\n", sb->s_id, 2468 sb->s_type->name); 2469 goto out_free_opts; 2470} 2471 2472static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) 2473{ 2474 const struct cred *cred = current_cred(); 2475 struct common_audit_data ad; 2476 int rc; 2477 2478 rc = superblock_doinit(sb, data); 2479 if (rc) 2480 return rc; 2481 2482 /* Allow all mounts performed by the kernel */ 2483 if (flags & MS_KERNMOUNT) 2484 return 0; 2485 2486 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 2487 ad.u.dentry = sb->s_root; 2488 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); 2489} 2490 2491static int selinux_sb_statfs(struct dentry *dentry) 2492{ 2493 const struct cred *cred = current_cred(); 2494 struct common_audit_data ad; 2495 2496 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 2497 ad.u.dentry = dentry->d_sb->s_root; 2498 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); 2499} 2500 2501static int selinux_mount(char *dev_name, 2502 struct path *path, 2503 char *type, 2504 unsigned long flags, 2505 void *data) 2506{ 2507 const struct cred *cred = current_cred(); 2508 2509 if (flags & MS_REMOUNT) 2510 return superblock_has_perm(cred, path->mnt->mnt_sb, 2511 FILESYSTEM__REMOUNT, NULL); 2512 else 2513 return path_has_perm(cred, path, FILE__MOUNTON); 2514} 2515 2516static int selinux_umount(struct vfsmount *mnt, int flags) 2517{ 2518 const struct cred *cred = current_cred(); 2519 2520 return superblock_has_perm(cred, mnt->mnt_sb, 2521 FILESYSTEM__UNMOUNT, NULL); 2522} 2523 2524/* inode security operations */ 2525 2526static int selinux_inode_alloc_security(struct inode *inode) 2527{ 2528 return inode_alloc_security(inode); 2529} 2530 2531static void selinux_inode_free_security(struct inode *inode) 2532{ 2533 inode_free_security(inode); 2534} 2535 2536static int selinux_inode_init_security(struct inode *inode, struct inode *dir, 2537 const struct qstr *qstr, char **name, 2538 void **value, size_t *len) 2539{ 2540 const struct task_security_struct *tsec = current_security(); 2541 struct inode_security_struct *dsec; 2542 struct superblock_security_struct *sbsec; 2543 u32 sid, newsid, clen; 2544 int rc; 2545 char *namep = NULL, *context; 2546 2547 dsec = dir->i_security; 2548 sbsec = dir->i_sb->s_security; 2549 2550 sid = tsec->sid; 2551 newsid = tsec->create_sid; 2552 2553 if ((sbsec->flags & SE_SBINITIALIZED) && 2554 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) 2555 newsid = sbsec->mntpoint_sid; 2556 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 2557 rc = security_transition_sid(sid, dsec->sid, 2558 inode_mode_to_security_class(inode->i_mode), 2559 qstr, &newsid); 2560 if (rc) { 2561 printk(KERN_WARNING "%s: " 2562 "security_transition_sid failed, rc=%d (dev=%s " 2563 "ino=%ld)\n", 2564 __func__, 2565 -rc, inode->i_sb->s_id, inode->i_ino); 2566 return rc; 2567 } 2568 } 2569 2570 /* Possibly defer initialization to selinux_complete_init. */ 2571 if (sbsec->flags & SE_SBINITIALIZED) { 2572 struct inode_security_struct *isec = inode->i_security; 2573 isec->sclass = inode_mode_to_security_class(inode->i_mode); 2574 isec->sid = newsid; 2575 isec->initialized = 1; 2576 } 2577 2578 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP)) 2579 return -EOPNOTSUPP; 2580 2581 if (name) { 2582 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS); 2583 if (!namep) 2584 return -ENOMEM; 2585 *name = namep; 2586 } 2587 2588 if (value && len) { 2589 rc = security_sid_to_context_force(newsid, &context, &clen); 2590 if (rc) { 2591 kfree(namep); 2592 return rc; 2593 } 2594 *value = context; 2595 *len = clen; 2596 } 2597 2598 return 0; 2599} 2600 2601static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask) 2602{ 2603 return may_create(dir, dentry, SECCLASS_FILE); 2604} 2605 2606static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) 2607{ 2608 return may_link(dir, old_dentry, MAY_LINK); 2609} 2610 2611static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) 2612{ 2613 return may_link(dir, dentry, MAY_UNLINK); 2614} 2615 2616static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) 2617{ 2618 return may_create(dir, dentry, SECCLASS_LNK_FILE); 2619} 2620 2621static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask) 2622{ 2623 return may_create(dir, dentry, SECCLASS_DIR); 2624} 2625 2626static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) 2627{ 2628 return may_link(dir, dentry, MAY_RMDIR); 2629} 2630 2631static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 2632{ 2633 return may_create(dir, dentry, inode_mode_to_security_class(mode)); 2634} 2635 2636static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, 2637 struct inode *new_inode, struct dentry *new_dentry) 2638{ 2639 return may_rename(old_inode, old_dentry, new_inode, new_dentry); 2640} 2641 2642static int selinux_inode_readlink(struct dentry *dentry) 2643{ 2644 const struct cred *cred = current_cred(); 2645 2646 return dentry_has_perm(cred, dentry, FILE__READ); 2647} 2648 2649static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata) 2650{ 2651 const struct cred *cred = current_cred(); 2652 2653 return dentry_has_perm(cred, dentry, FILE__READ); 2654} 2655 2656static int selinux_inode_permission(struct inode *inode, int mask) 2657{ 2658 const struct cred *cred = current_cred(); 2659 struct common_audit_data ad; 2660 u32 perms; 2661 bool from_access; 2662 unsigned flags = mask & MAY_NOT_BLOCK; 2663 2664 from_access = mask & MAY_ACCESS; 2665 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 2666 2667 /* No permission to check. Existence test. */ 2668 if (!mask) 2669 return 0; 2670 2671 COMMON_AUDIT_DATA_INIT(&ad, INODE); 2672 ad.u.inode = inode; 2673 2674 if (from_access) 2675 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS; 2676 2677 perms = file_mask_to_av(inode->i_mode, mask); 2678 2679 return inode_has_perm(cred, inode, perms, &ad, flags); 2680} 2681 2682static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) 2683{ 2684 const struct cred *cred = current_cred(); 2685 unsigned int ia_valid = iattr->ia_valid; 2686 2687 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ 2688 if (ia_valid & ATTR_FORCE) { 2689 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | 2690 ATTR_FORCE); 2691 if (!ia_valid) 2692 return 0; 2693 } 2694 2695 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | 2696 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) 2697 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2698 2699 return dentry_has_perm(cred, dentry, FILE__WRITE); 2700} 2701 2702static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 2703{ 2704 const struct cred *cred = current_cred(); 2705 struct path path; 2706 2707 path.dentry = dentry; 2708 path.mnt = mnt; 2709 2710 return path_has_perm(cred, &path, FILE__GETATTR); 2711} 2712 2713static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) 2714{ 2715 const struct cred *cred = current_cred(); 2716 2717 if (!strncmp(name, XATTR_SECURITY_PREFIX, 2718 sizeof XATTR_SECURITY_PREFIX - 1)) { 2719 if (!strcmp(name, XATTR_NAME_CAPS)) { 2720 if (!capable(CAP_SETFCAP)) 2721 return -EPERM; 2722 } else if (!capable(CAP_SYS_ADMIN)) { 2723 /* A different attribute in the security namespace. 2724 Restrict to administrator. */ 2725 return -EPERM; 2726 } 2727 } 2728 2729 /* Not an attribute we recognize, so just check the 2730 ordinary setattr permission. */ 2731 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2732} 2733 2734static int selinux_inode_setxattr(struct dentry *dentry, const char *name, 2735 const void *value, size_t size, int flags) 2736{ 2737 struct inode *inode = dentry->d_inode; 2738 struct inode_security_struct *isec = inode->i_security; 2739 struct superblock_security_struct *sbsec; 2740 struct common_audit_data ad; 2741 u32 newsid, sid = current_sid(); 2742 int rc = 0; 2743 2744 if (strcmp(name, XATTR_NAME_SELINUX)) 2745 return selinux_inode_setotherxattr(dentry, name); 2746 2747 sbsec = inode->i_sb->s_security; 2748 if (!(sbsec->flags & SE_SBLABELSUPP)) 2749 return -EOPNOTSUPP; 2750 2751 if (!inode_owner_or_capable(inode)) 2752 return -EPERM; 2753 2754 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 2755 ad.u.dentry = dentry; 2756 2757 rc = avc_has_perm(sid, isec->sid, isec->sclass, 2758 FILE__RELABELFROM, &ad); 2759 if (rc) 2760 return rc; 2761 2762 rc = security_context_to_sid(value, size, &newsid); 2763 if (rc == -EINVAL) { 2764 if (!capable(CAP_MAC_ADMIN)) 2765 return rc; 2766 rc = security_context_to_sid_force(value, size, &newsid); 2767 } 2768 if (rc) 2769 return rc; 2770 2771 rc = avc_has_perm(sid, newsid, isec->sclass, 2772 FILE__RELABELTO, &ad); 2773 if (rc) 2774 return rc; 2775 2776 rc = security_validate_transition(isec->sid, newsid, sid, 2777 isec->sclass); 2778 if (rc) 2779 return rc; 2780 2781 return avc_has_perm(newsid, 2782 sbsec->sid, 2783 SECCLASS_FILESYSTEM, 2784 FILESYSTEM__ASSOCIATE, 2785 &ad); 2786} 2787 2788static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, 2789 const void *value, size_t size, 2790 int flags) 2791{ 2792 struct inode *inode = dentry->d_inode; 2793 struct inode_security_struct *isec = inode->i_security; 2794 u32 newsid; 2795 int rc; 2796 2797 if (strcmp(name, XATTR_NAME_SELINUX)) { 2798 /* Not an attribute we recognize, so nothing to do. */ 2799 return; 2800 } 2801 2802 rc = security_context_to_sid_force(value, size, &newsid); 2803 if (rc) { 2804 printk(KERN_ERR "SELinux: unable to map context to SID" 2805 "for (%s, %lu), rc=%d\n", 2806 inode->i_sb->s_id, inode->i_ino, -rc); 2807 return; 2808 } 2809 2810 isec->sid = newsid; 2811 return; 2812} 2813 2814static int selinux_inode_getxattr(struct dentry *dentry, const char *name) 2815{ 2816 const struct cred *cred = current_cred(); 2817 2818 return dentry_has_perm(cred, dentry, FILE__GETATTR); 2819} 2820 2821static int selinux_inode_listxattr(struct dentry *dentry) 2822{ 2823 const struct cred *cred = current_cred(); 2824 2825 return dentry_has_perm(cred, dentry, FILE__GETATTR); 2826} 2827 2828static int selinux_inode_removexattr(struct dentry *dentry, const char *name) 2829{ 2830 if (strcmp(name, XATTR_NAME_SELINUX)) 2831 return selinux_inode_setotherxattr(dentry, name); 2832 2833 /* No one is allowed to remove a SELinux security label. 2834 You can change the label, but all data must be labeled. */ 2835 return -EACCES; 2836} 2837 2838/* 2839 * Copy the inode security context value to the user. 2840 * 2841 * Permission check is handled by selinux_inode_getxattr hook. 2842 */ 2843static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) 2844{ 2845 u32 size; 2846 int error; 2847 char *context = NULL; 2848 struct inode_security_struct *isec = inode->i_security; 2849 2850 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2851 return -EOPNOTSUPP; 2852 2853 /* 2854 * If the caller has CAP_MAC_ADMIN, then get the raw context 2855 * value even if it is not defined by current policy; otherwise, 2856 * use the in-core value under current policy. 2857 * Use the non-auditing forms of the permission checks since 2858 * getxattr may be called by unprivileged processes commonly 2859 * and lack of permission just means that we fall back to the 2860 * in-core context value, not a denial. 2861 */ 2862 error = selinux_capable(current, current_cred(), 2863 &init_user_ns, CAP_MAC_ADMIN, 2864 SECURITY_CAP_NOAUDIT); 2865 if (!error) 2866 error = security_sid_to_context_force(isec->sid, &context, 2867 &size); 2868 else 2869 error = security_sid_to_context(isec->sid, &context, &size); 2870 if (error) 2871 return error; 2872 error = size; 2873 if (alloc) { 2874 *buffer = context; 2875 goto out_nofree; 2876 } 2877 kfree(context); 2878out_nofree: 2879 return error; 2880} 2881 2882static int selinux_inode_setsecurity(struct inode *inode, const char *name, 2883 const void *value, size_t size, int flags) 2884{ 2885 struct inode_security_struct *isec = inode->i_security; 2886 u32 newsid; 2887 int rc; 2888 2889 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2890 return -EOPNOTSUPP; 2891 2892 if (!value || !size) 2893 return -EACCES; 2894 2895 rc = security_context_to_sid((void *)value, size, &newsid); 2896 if (rc) 2897 return rc; 2898 2899 isec->sid = newsid; 2900 isec->initialized = 1; 2901 return 0; 2902} 2903 2904static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) 2905{ 2906 const int len = sizeof(XATTR_NAME_SELINUX); 2907 if (buffer && len <= buffer_size) 2908 memcpy(buffer, XATTR_NAME_SELINUX, len); 2909 return len; 2910} 2911 2912static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) 2913{ 2914 struct inode_security_struct *isec = inode->i_security; 2915 *secid = isec->sid; 2916} 2917 2918/* file security operations */ 2919 2920static int selinux_revalidate_file_permission(struct file *file, int mask) 2921{ 2922 const struct cred *cred = current_cred(); 2923 struct inode *inode = file->f_path.dentry->d_inode; 2924 2925 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ 2926 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) 2927 mask |= MAY_APPEND; 2928 2929 return file_has_perm(cred, file, 2930 file_mask_to_av(inode->i_mode, mask)); 2931} 2932 2933static int selinux_file_permission(struct file *file, int mask) 2934{ 2935 struct inode *inode = file->f_path.dentry->d_inode; 2936 struct file_security_struct *fsec = file->f_security; 2937 struct inode_security_struct *isec = inode->i_security; 2938 u32 sid = current_sid(); 2939 2940 if (!mask) 2941 /* No permission to check. Existence test. */ 2942 return 0; 2943 2944 if (sid == fsec->sid && fsec->isid == isec->sid && 2945 fsec->pseqno == avc_policy_seqno()) 2946 /* No change since dentry_open check. */ 2947 return 0; 2948 2949 return selinux_revalidate_file_permission(file, mask); 2950} 2951 2952static int selinux_file_alloc_security(struct file *file) 2953{ 2954 return file_alloc_security(file); 2955} 2956 2957static void selinux_file_free_security(struct file *file) 2958{ 2959 file_free_security(file); 2960} 2961 2962static int selinux_file_ioctl(struct file *file, unsigned int cmd, 2963 unsigned long arg) 2964{ 2965 const struct cred *cred = current_cred(); 2966 int error = 0; 2967 2968 switch (cmd) { 2969 case FIONREAD: 2970 /* fall through */ 2971 case FIBMAP: 2972 /* fall through */ 2973 case FIGETBSZ: 2974 /* fall through */ 2975 case EXT2_IOC_GETFLAGS: 2976 /* fall through */ 2977 case EXT2_IOC_GETVERSION: 2978 error = file_has_perm(cred, file, FILE__GETATTR); 2979 break; 2980 2981 case EXT2_IOC_SETFLAGS: 2982 /* fall through */ 2983 case EXT2_IOC_SETVERSION: 2984 error = file_has_perm(cred, file, FILE__SETATTR); 2985 break; 2986 2987 /* sys_ioctl() checks */ 2988 case FIONBIO: 2989 /* fall through */ 2990 case FIOASYNC: 2991 error = file_has_perm(cred, file, 0); 2992 break; 2993 2994 case KDSKBENT: 2995 case KDSKBSENT: 2996 error = task_has_capability(current, cred, CAP_SYS_TTY_CONFIG, 2997 SECURITY_CAP_AUDIT); 2998 break; 2999 3000 /* default case assumes that the command will go 3001 * to the file's ioctl() function. 3002 */ 3003 default: 3004 error = file_has_perm(cred, file, FILE__IOCTL); 3005 } 3006 return error; 3007} 3008 3009static int default_noexec; 3010 3011static int file_map_prot_check(struct file *file, unsigned long prot, int shared) 3012{ 3013 const struct cred *cred = current_cred(); 3014 int rc = 0; 3015 3016 if (default_noexec && 3017 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { 3018 /* 3019 * We are making executable an anonymous mapping or a 3020 * private file mapping that will also be writable. 3021 * This has an additional check. 3022 */ 3023 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM); 3024 if (rc) 3025 goto error; 3026 } 3027 3028 if (file) { 3029 /* read access is always possible with a mapping */ 3030 u32 av = FILE__READ; 3031 3032 /* write access only matters if the mapping is shared */ 3033 if (shared && (prot & PROT_WRITE)) 3034 av |= FILE__WRITE; 3035 3036 if (prot & PROT_EXEC) 3037 av |= FILE__EXECUTE; 3038 3039 return file_has_perm(cred, file, av); 3040 } 3041 3042error: 3043 return rc; 3044} 3045 3046static int selinux_file_mmap(struct file *file, unsigned long reqprot, 3047 unsigned long prot, unsigned long flags, 3048 unsigned long addr, unsigned long addr_only) 3049{ 3050 int rc = 0; 3051 u32 sid = current_sid(); 3052 3053 /* 3054 * notice that we are intentionally putting the SELinux check before 3055 * the secondary cap_file_mmap check. This is such a likely attempt 3056 * at bad behaviour/exploit that we always want to get the AVC, even 3057 * if DAC would have also denied the operation. 3058 */ 3059 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { 3060 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, 3061 MEMPROTECT__MMAP_ZERO, NULL); 3062 if (rc) 3063 return rc; 3064 } 3065 3066 /* do DAC check on address space usage */ 3067 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); 3068 if (rc || addr_only) 3069 return rc; 3070 3071 if (selinux_checkreqprot) 3072 prot = reqprot; 3073 3074 return file_map_prot_check(file, prot, 3075 (flags & MAP_TYPE) == MAP_SHARED); 3076} 3077 3078static int selinux_file_mprotect(struct vm_area_struct *vma, 3079 unsigned long reqprot, 3080 unsigned long prot) 3081{ 3082 const struct cred *cred = current_cred(); 3083 3084 if (selinux_checkreqprot) 3085 prot = reqprot; 3086 3087 if (default_noexec && 3088 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { 3089 int rc = 0; 3090 if (vma->vm_start >= vma->vm_mm->start_brk && 3091 vma->vm_end <= vma->vm_mm->brk) { 3092 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP); 3093 } else if (!vma->vm_file && 3094 vma->vm_start <= vma->vm_mm->start_stack && 3095 vma->vm_end >= vma->vm_mm->start_stack) { 3096 rc = current_has_perm(current, PROCESS__EXECSTACK); 3097 } else if (vma->vm_file && vma->anon_vma) { 3098 /* 3099 * We are making executable a file mapping that has 3100 * had some COW done. Since pages might have been 3101 * written, check ability to execute the possibly 3102 * modified content. This typically should only 3103 * occur for text relocations. 3104 */ 3105 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); 3106 } 3107 if (rc) 3108 return rc; 3109 } 3110 3111 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED); 3112} 3113 3114static int selinux_file_lock(struct file *file, unsigned int cmd) 3115{ 3116 const struct cred *cred = current_cred(); 3117 3118 return file_has_perm(cred, file, FILE__LOCK); 3119} 3120 3121static int selinux_file_fcntl(struct file *file, unsigned int cmd, 3122 unsigned long arg) 3123{ 3124 const struct cred *cred = current_cred(); 3125 int err = 0; 3126 3127 switch (cmd) { 3128 case F_SETFL: 3129 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3130 err = -EINVAL; 3131 break; 3132 } 3133 3134 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) { 3135 err = file_has_perm(cred, file, FILE__WRITE); 3136 break; 3137 } 3138 /* fall through */ 3139 case F_SETOWN: 3140 case F_SETSIG: 3141 case F_GETFL: 3142 case F_GETOWN: 3143 case F_GETSIG: 3144 /* Just check FD__USE permission */ 3145 err = file_has_perm(cred, file, 0); 3146 break; 3147 case F_GETLK: 3148 case F_SETLK: 3149 case F_SETLKW: 3150#if BITS_PER_LONG == 32 3151 case F_GETLK64: 3152 case F_SETLK64: 3153 case F_SETLKW64: 3154#endif 3155 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3156 err = -EINVAL; 3157 break; 3158 } 3159 err = file_has_perm(cred, file, FILE__LOCK); 3160 break; 3161 } 3162 3163 return err; 3164} 3165 3166static int selinux_file_set_fowner(struct file *file) 3167{ 3168 struct file_security_struct *fsec; 3169 3170 fsec = file->f_security; 3171 fsec->fown_sid = current_sid(); 3172 3173 return 0; 3174} 3175 3176static int selinux_file_send_sigiotask(struct task_struct *tsk, 3177 struct fown_struct *fown, int signum) 3178{ 3179 struct file *file; 3180 u32 sid = task_sid(tsk); 3181 u32 perm; 3182 struct file_security_struct *fsec; 3183 3184 /* struct fown_struct is never outside the context of a struct file */ 3185 file = container_of(fown, struct file, f_owner); 3186 3187 fsec = file->f_security; 3188 3189 if (!signum) 3190 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */ 3191 else 3192 perm = signal_to_av(signum); 3193 3194 return avc_has_perm(fsec->fown_sid, sid, 3195 SECCLASS_PROCESS, perm, NULL); 3196} 3197 3198static int selinux_file_receive(struct file *file) 3199{ 3200 const struct cred *cred = current_cred(); 3201 3202 return file_has_perm(cred, file, file_to_av(file)); 3203} 3204 3205static int selinux_dentry_open(struct file *file, const struct cred *cred) 3206{ 3207 struct file_security_struct *fsec; 3208 struct inode *inode; 3209 struct inode_security_struct *isec; 3210 3211 inode = file->f_path.dentry->d_inode; 3212 fsec = file->f_security; 3213 isec = inode->i_security; 3214 /* 3215 * Save inode label and policy sequence number 3216 * at open-time so that selinux_file_permission 3217 * can determine whether revalidation is necessary. 3218 * Task label is already saved in the file security 3219 * struct as its SID. 3220 */ 3221 fsec->isid = isec->sid; 3222 fsec->pseqno = avc_policy_seqno(); 3223 /* 3224 * Since the inode label or policy seqno may have changed 3225 * between the selinux_inode_permission check and the saving 3226 * of state above, recheck that access is still permitted. 3227 * Otherwise, access might never be revalidated against the 3228 * new inode label or new policy. 3229 * This check is not redundant - do not remove. 3230 */ 3231 return inode_has_perm_noadp(cred, inode, open_file_to_av(file), 0); 3232} 3233 3234/* task security operations */ 3235 3236static int selinux_task_create(unsigned long clone_flags) 3237{ 3238 return current_has_perm(current, PROCESS__FORK); 3239} 3240 3241/* 3242 * allocate the SELinux part of blank credentials 3243 */ 3244static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp) 3245{ 3246 struct task_security_struct *tsec; 3247 3248 tsec = kzalloc(sizeof(struct task_security_struct), gfp); 3249 if (!tsec) 3250 return -ENOMEM; 3251 3252 cred->security = tsec; 3253 return 0; 3254} 3255 3256/* 3257 * detach and free the LSM part of a set of credentials 3258 */ 3259static void selinux_cred_free(struct cred *cred) 3260{ 3261 struct task_security_struct *tsec = cred->security; 3262 3263 /* 3264 * cred->security == NULL if security_cred_alloc_blank() or 3265 * security_prepare_creds() returned an error. 3266 */ 3267 BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE); 3268 cred->security = (void *) 0x7UL; 3269 kfree(tsec); 3270} 3271 3272/* 3273 * prepare a new set of credentials for modification 3274 */ 3275static int selinux_cred_prepare(struct cred *new, const struct cred *old, 3276 gfp_t gfp) 3277{ 3278 const struct task_security_struct *old_tsec; 3279 struct task_security_struct *tsec; 3280 3281 old_tsec = old->security; 3282 3283 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp); 3284 if (!tsec) 3285 return -ENOMEM; 3286 3287 new->security = tsec; 3288 return 0; 3289} 3290 3291/* 3292 * transfer the SELinux data to a blank set of creds 3293 */ 3294static void selinux_cred_transfer(struct cred *new, const struct cred *old) 3295{ 3296 const struct task_security_struct *old_tsec = old->security; 3297 struct task_security_struct *tsec = new->security; 3298 3299 *tsec = *old_tsec; 3300} 3301 3302/* 3303 * set the security data for a kernel service 3304 * - all the creation contexts are set to unlabelled 3305 */ 3306static int selinux_kernel_act_as(struct cred *new, u32 secid) 3307{ 3308 struct task_security_struct *tsec = new->security; 3309 u32 sid = current_sid(); 3310 int ret; 3311 3312 ret = avc_has_perm(sid, secid, 3313 SECCLASS_KERNEL_SERVICE, 3314 KERNEL_SERVICE__USE_AS_OVERRIDE, 3315 NULL); 3316 if (ret == 0) { 3317 tsec->sid = secid; 3318 tsec->create_sid = 0; 3319 tsec->keycreate_sid = 0; 3320 tsec->sockcreate_sid = 0; 3321 } 3322 return ret; 3323} 3324 3325/* 3326 * set the file creation context in a security record to the same as the 3327 * objective context of the specified inode 3328 */ 3329static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) 3330{ 3331 struct inode_security_struct *isec = inode->i_security; 3332 struct task_security_struct *tsec = new->security; 3333 u32 sid = current_sid(); 3334 int ret; 3335 3336 ret = avc_has_perm(sid, isec->sid, 3337 SECCLASS_KERNEL_SERVICE, 3338 KERNEL_SERVICE__CREATE_FILES_AS, 3339 NULL); 3340 3341 if (ret == 0) 3342 tsec->create_sid = isec->sid; 3343 return ret; 3344} 3345 3346static int selinux_kernel_module_request(char *kmod_name) 3347{ 3348 u32 sid; 3349 struct common_audit_data ad; 3350 3351 sid = task_sid(current); 3352 3353 COMMON_AUDIT_DATA_INIT(&ad, KMOD); 3354 ad.u.kmod_name = kmod_name; 3355 3356 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM, 3357 SYSTEM__MODULE_REQUEST, &ad); 3358} 3359 3360static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) 3361{ 3362 return current_has_perm(p, PROCESS__SETPGID); 3363} 3364 3365static int selinux_task_getpgid(struct task_struct *p) 3366{ 3367 return current_has_perm(p, PROCESS__GETPGID); 3368} 3369 3370static int selinux_task_getsid(struct task_struct *p) 3371{ 3372 return current_has_perm(p, PROCESS__GETSESSION); 3373} 3374 3375static void selinux_task_getsecid(struct task_struct *p, u32 *secid) 3376{ 3377 *secid = task_sid(p); 3378} 3379 3380static int selinux_task_setnice(struct task_struct *p, int nice) 3381{ 3382 int rc; 3383 3384 rc = cap_task_setnice(p, nice); 3385 if (rc) 3386 return rc; 3387 3388 return current_has_perm(p, PROCESS__SETSCHED); 3389} 3390 3391static int selinux_task_setioprio(struct task_struct *p, int ioprio) 3392{ 3393 int rc; 3394 3395 rc = cap_task_setioprio(p, ioprio); 3396 if (rc) 3397 return rc; 3398 3399 return current_has_perm(p, PROCESS__SETSCHED); 3400} 3401 3402static int selinux_task_getioprio(struct task_struct *p) 3403{ 3404 return current_has_perm(p, PROCESS__GETSCHED); 3405} 3406 3407static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, 3408 struct rlimit *new_rlim) 3409{ 3410 struct rlimit *old_rlim = p->signal->rlim + resource; 3411 3412 /* Control the ability to change the hard limit (whether 3413 lowering or raising it), so that the hard limit can 3414 later be used as a safe reset point for the soft limit 3415 upon context transitions. See selinux_bprm_committing_creds. */ 3416 if (old_rlim->rlim_max != new_rlim->rlim_max) 3417 return current_has_perm(p, PROCESS__SETRLIMIT); 3418 3419 return 0; 3420} 3421 3422static int selinux_task_setscheduler(struct task_struct *p) 3423{ 3424 int rc; 3425 3426 rc = cap_task_setscheduler(p); 3427 if (rc) 3428 return rc; 3429 3430 return current_has_perm(p, PROCESS__SETSCHED); 3431} 3432 3433static int selinux_task_getscheduler(struct task_struct *p) 3434{ 3435 return current_has_perm(p, PROCESS__GETSCHED); 3436} 3437 3438static int selinux_task_movememory(struct task_struct *p) 3439{ 3440 return current_has_perm(p, PROCESS__SETSCHED); 3441} 3442 3443static int selinux_task_kill(struct task_struct *p, struct siginfo *info, 3444 int sig, u32 secid) 3445{ 3446 u32 perm; 3447 int rc; 3448 3449 if (!sig) 3450 perm = PROCESS__SIGNULL; /* null signal; existence test */ 3451 else 3452 perm = signal_to_av(sig); 3453 if (secid) 3454 rc = avc_has_perm(secid, task_sid(p), 3455 SECCLASS_PROCESS, perm, NULL); 3456 else 3457 rc = current_has_perm(p, perm); 3458 return rc; 3459} 3460 3461static int selinux_task_wait(struct task_struct *p) 3462{ 3463 return task_has_perm(p, current, PROCESS__SIGCHLD); 3464} 3465 3466static void selinux_task_to_inode(struct task_struct *p, 3467 struct inode *inode) 3468{ 3469 struct inode_security_struct *isec = inode->i_security; 3470 u32 sid = task_sid(p); 3471 3472 isec->sid = sid; 3473 isec->initialized = 1; 3474} 3475 3476/* Returns error only if unable to parse addresses */ 3477static int selinux_parse_skb_ipv4(struct sk_buff *skb, 3478 struct common_audit_data *ad, u8 *proto) 3479{ 3480 int offset, ihlen, ret = -EINVAL; 3481 struct iphdr _iph, *ih; 3482 3483 offset = skb_network_offset(skb); 3484 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); 3485 if (ih == NULL) 3486 goto out; 3487 3488 ihlen = ih->ihl * 4; 3489 if (ihlen < sizeof(_iph)) 3490 goto out; 3491 3492 ad->u.net.v4info.saddr = ih->saddr; 3493 ad->u.net.v4info.daddr = ih->daddr; 3494 ret = 0; 3495 3496 if (proto) 3497 *proto = ih->protocol; 3498 3499 switch (ih->protocol) { 3500 case IPPROTO_TCP: { 3501 struct tcphdr _tcph, *th; 3502 3503 if (ntohs(ih->frag_off) & IP_OFFSET) 3504 break; 3505 3506 offset += ihlen; 3507 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3508 if (th == NULL) 3509 break; 3510 3511 ad->u.net.sport = th->source; 3512 ad->u.net.dport = th->dest; 3513 break; 3514 } 3515 3516 case IPPROTO_UDP: { 3517 struct udphdr _udph, *uh; 3518 3519 if (ntohs(ih->frag_off) & IP_OFFSET) 3520 break; 3521 3522 offset += ihlen; 3523 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3524 if (uh == NULL) 3525 break; 3526 3527 ad->u.net.sport = uh->source; 3528 ad->u.net.dport = uh->dest; 3529 break; 3530 } 3531 3532 case IPPROTO_DCCP: { 3533 struct dccp_hdr _dccph, *dh; 3534 3535 if (ntohs(ih->frag_off) & IP_OFFSET) 3536 break; 3537 3538 offset += ihlen; 3539 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3540 if (dh == NULL) 3541 break; 3542 3543 ad->u.net.sport = dh->dccph_sport; 3544 ad->u.net.dport = dh->dccph_dport; 3545 break; 3546 } 3547 3548 default: 3549 break; 3550 } 3551out: 3552 return ret; 3553} 3554 3555#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3556 3557/* Returns error only if unable to parse addresses */ 3558static int selinux_parse_skb_ipv6(struct sk_buff *skb, 3559 struct common_audit_data *ad, u8 *proto) 3560{ 3561 u8 nexthdr; 3562 int ret = -EINVAL, offset; 3563 struct ipv6hdr _ipv6h, *ip6; 3564 __be16 frag_off; 3565 3566 offset = skb_network_offset(skb); 3567 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); 3568 if (ip6 == NULL) 3569 goto out; 3570 3571 ad->u.net.v6info.saddr = ip6->saddr; 3572 ad->u.net.v6info.daddr = ip6->daddr; 3573 ret = 0; 3574 3575 nexthdr = ip6->nexthdr; 3576 offset += sizeof(_ipv6h); 3577 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 3578 if (offset < 0) 3579 goto out; 3580 3581 if (proto) 3582 *proto = nexthdr; 3583 3584 switch (nexthdr) { 3585 case IPPROTO_TCP: { 3586 struct tcphdr _tcph, *th; 3587 3588 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3589 if (th == NULL) 3590 break; 3591 3592 ad->u.net.sport = th->source; 3593 ad->u.net.dport = th->dest; 3594 break; 3595 } 3596 3597 case IPPROTO_UDP: { 3598 struct udphdr _udph, *uh; 3599 3600 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3601 if (uh == NULL) 3602 break; 3603 3604 ad->u.net.sport = uh->source; 3605 ad->u.net.dport = uh->dest; 3606 break; 3607 } 3608 3609 case IPPROTO_DCCP: { 3610 struct dccp_hdr _dccph, *dh; 3611 3612 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3613 if (dh == NULL) 3614 break; 3615 3616 ad->u.net.sport = dh->dccph_sport; 3617 ad->u.net.dport = dh->dccph_dport; 3618 break; 3619 } 3620 3621 /* includes fragments */ 3622 default: 3623 break; 3624 } 3625out: 3626 return ret; 3627} 3628 3629#endif /* IPV6 */ 3630 3631static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad, 3632 char **_addrp, int src, u8 *proto) 3633{ 3634 char *addrp; 3635 int ret; 3636 3637 switch (ad->u.net.family) { 3638 case PF_INET: 3639 ret = selinux_parse_skb_ipv4(skb, ad, proto); 3640 if (ret) 3641 goto parse_error; 3642 addrp = (char *)(src ? &ad->u.net.v4info.saddr : 3643 &ad->u.net.v4info.daddr); 3644 goto okay; 3645 3646#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3647 case PF_INET6: 3648 ret = selinux_parse_skb_ipv6(skb, ad, proto); 3649 if (ret) 3650 goto parse_error; 3651 addrp = (char *)(src ? &ad->u.net.v6info.saddr : 3652 &ad->u.net.v6info.daddr); 3653 goto okay; 3654#endif /* IPV6 */ 3655 default: 3656 addrp = NULL; 3657 goto okay; 3658 } 3659 3660parse_error: 3661 printk(KERN_WARNING 3662 "SELinux: failure in selinux_parse_skb()," 3663 " unable to parse packet\n"); 3664 return ret; 3665 3666okay: 3667 if (_addrp) 3668 *_addrp = addrp; 3669 return 0; 3670} 3671 3672/** 3673 * selinux_skb_peerlbl_sid - Determine the peer label of a packet 3674 * @skb: the packet 3675 * @family: protocol family 3676 * @sid: the packet's peer label SID 3677 * 3678 * Description: 3679 * Check the various different forms of network peer labeling and determine 3680 * the peer label/SID for the packet; most of the magic actually occurs in 3681 * the security server function security_net_peersid_cmp(). The function 3682 * returns zero if the value in @sid is valid (although it may be SECSID_NULL) 3683 * or -EACCES if @sid is invalid due to inconsistencies with the different 3684 * peer labels. 3685 * 3686 */ 3687static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) 3688{ 3689 int err; 3690 u32 xfrm_sid; 3691 u32 nlbl_sid; 3692 u32 nlbl_type; 3693 3694 selinux_skb_xfrm_sid(skb, &xfrm_sid); 3695 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); 3696 3697 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid); 3698 if (unlikely(err)) { 3699 printk(KERN_WARNING 3700 "SELinux: failure in selinux_skb_peerlbl_sid()," 3701 " unable to determine packet's peer label\n"); 3702 return -EACCES; 3703 } 3704 3705 return 0; 3706} 3707 3708/* socket security operations */ 3709 3710static int socket_sockcreate_sid(const struct task_security_struct *tsec, 3711 u16 secclass, u32 *socksid) 3712{ 3713 if (tsec->sockcreate_sid > SECSID_NULL) { 3714 *socksid = tsec->sockcreate_sid; 3715 return 0; 3716 } 3717 3718 return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL, 3719 socksid); 3720} 3721 3722static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms) 3723{ 3724 struct sk_security_struct *sksec = sk->sk_security; 3725 struct common_audit_data ad; 3726 u32 tsid = task_sid(task); 3727 3728 if (sksec->sid == SECINITSID_KERNEL) 3729 return 0; 3730 3731 COMMON_AUDIT_DATA_INIT(&ad, NET); 3732 ad.u.net.sk = sk; 3733 3734 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad); 3735} 3736 3737static int selinux_socket_create(int family, int type, 3738 int protocol, int kern) 3739{ 3740 const struct task_security_struct *tsec = current_security(); 3741 u32 newsid; 3742 u16 secclass; 3743 int rc; 3744 3745 if (kern) 3746 return 0; 3747 3748 secclass = socket_type_to_security_class(family, type, protocol); 3749 rc = socket_sockcreate_sid(tsec, secclass, &newsid); 3750 if (rc) 3751 return rc; 3752 3753 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL); 3754} 3755 3756static int selinux_socket_post_create(struct socket *sock, int family, 3757 int type, int protocol, int kern) 3758{ 3759 const struct task_security_struct *tsec = current_security(); 3760 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; 3761 struct sk_security_struct *sksec; 3762 int err = 0; 3763 3764 isec->sclass = socket_type_to_security_class(family, type, protocol); 3765 3766 if (kern) 3767 isec->sid = SECINITSID_KERNEL; 3768 else { 3769 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid)); 3770 if (err) 3771 return err; 3772 } 3773 3774 isec->initialized = 1; 3775 3776 if (sock->sk) { 3777 sksec = sock->sk->sk_security; 3778 sksec->sid = isec->sid; 3779 sksec->sclass = isec->sclass; 3780 err = selinux_netlbl_socket_post_create(sock->sk, family); 3781 } 3782 3783 return err; 3784} 3785 3786/* Range of port numbers used to automatically bind. 3787 Need to determine whether we should perform a name_bind 3788 permission check between the socket and the port number. */ 3789 3790static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) 3791{ 3792 struct sock *sk = sock->sk; 3793 u16 family; 3794 int err; 3795 3796 err = sock_has_perm(current, sk, SOCKET__BIND); 3797 if (err) 3798 goto out; 3799 3800 /* 3801 * If PF_INET or PF_INET6, check name_bind permission for the port. 3802 * Multiple address binding for SCTP is not supported yet: we just 3803 * check the first address now. 3804 */ 3805 family = sk->sk_family; 3806 if (family == PF_INET || family == PF_INET6) { 3807 char *addrp; 3808 struct sk_security_struct *sksec = sk->sk_security; 3809 struct common_audit_data ad; 3810 struct sockaddr_in *addr4 = NULL; 3811 struct sockaddr_in6 *addr6 = NULL; 3812 unsigned short snum; 3813 u32 sid, node_perm; 3814 3815 if (family == PF_INET) { 3816 addr4 = (struct sockaddr_in *)address; 3817 snum = ntohs(addr4->sin_port); 3818 addrp = (char *)&addr4->sin_addr.s_addr; 3819 } else { 3820 addr6 = (struct sockaddr_in6 *)address; 3821 snum = ntohs(addr6->sin6_port); 3822 addrp = (char *)&addr6->sin6_addr.s6_addr; 3823 } 3824 3825 if (snum) { 3826 int low, high; 3827 3828 inet_get_local_port_range(&low, &high); 3829 3830 if (snum < max(PROT_SOCK, low) || snum > high) { 3831 err = sel_netport_sid(sk->sk_protocol, 3832 snum, &sid); 3833 if (err) 3834 goto out; 3835 COMMON_AUDIT_DATA_INIT(&ad, NET); 3836 ad.u.net.sport = htons(snum); 3837 ad.u.net.family = family; 3838 err = avc_has_perm(sksec->sid, sid, 3839 sksec->sclass, 3840 SOCKET__NAME_BIND, &ad); 3841 if (err) 3842 goto out; 3843 } 3844 } 3845 3846 switch (sksec->sclass) { 3847 case SECCLASS_TCP_SOCKET: 3848 node_perm = TCP_SOCKET__NODE_BIND; 3849 break; 3850 3851 case SECCLASS_UDP_SOCKET: 3852 node_perm = UDP_SOCKET__NODE_BIND; 3853 break; 3854 3855 case SECCLASS_DCCP_SOCKET: 3856 node_perm = DCCP_SOCKET__NODE_BIND; 3857 break; 3858 3859 default: 3860 node_perm = RAWIP_SOCKET__NODE_BIND; 3861 break; 3862 } 3863 3864 err = sel_netnode_sid(addrp, family, &sid); 3865 if (err) 3866 goto out; 3867 3868 COMMON_AUDIT_DATA_INIT(&ad, NET); 3869 ad.u.net.sport = htons(snum); 3870 ad.u.net.family = family; 3871 3872 if (family == PF_INET) 3873 ad.u.net.v4info.saddr = addr4->sin_addr.s_addr; 3874 else 3875 ad.u.net.v6info.saddr = addr6->sin6_addr; 3876 3877 err = avc_has_perm(sksec->sid, sid, 3878 sksec->sclass, node_perm, &ad); 3879 if (err) 3880 goto out; 3881 } 3882out: 3883 return err; 3884} 3885 3886static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) 3887{ 3888 struct sock *sk = sock->sk; 3889 struct sk_security_struct *sksec = sk->sk_security; 3890 int err; 3891 3892 err = sock_has_perm(current, sk, SOCKET__CONNECT); 3893 if (err) 3894 return err; 3895 3896 /* 3897 * If a TCP or DCCP socket, check name_connect permission for the port. 3898 */ 3899 if (sksec->sclass == SECCLASS_TCP_SOCKET || 3900 sksec->sclass == SECCLASS_DCCP_SOCKET) { 3901 struct common_audit_data ad; 3902 struct sockaddr_in *addr4 = NULL; 3903 struct sockaddr_in6 *addr6 = NULL; 3904 unsigned short snum; 3905 u32 sid, perm; 3906 3907 if (sk->sk_family == PF_INET) { 3908 addr4 = (struct sockaddr_in *)address; 3909 if (addrlen < sizeof(struct sockaddr_in)) 3910 return -EINVAL; 3911 snum = ntohs(addr4->sin_port); 3912 } else { 3913 addr6 = (struct sockaddr_in6 *)address; 3914 if (addrlen < SIN6_LEN_RFC2133) 3915 return -EINVAL; 3916 snum = ntohs(addr6->sin6_port); 3917 } 3918 3919 err = sel_netport_sid(sk->sk_protocol, snum, &sid); 3920 if (err) 3921 goto out; 3922 3923 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ? 3924 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT; 3925 3926 COMMON_AUDIT_DATA_INIT(&ad, NET); 3927 ad.u.net.dport = htons(snum); 3928 ad.u.net.family = sk->sk_family; 3929 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad); 3930 if (err) 3931 goto out; 3932 } 3933 3934 err = selinux_netlbl_socket_connect(sk, address); 3935 3936out: 3937 return err; 3938} 3939 3940static int selinux_socket_listen(struct socket *sock, int backlog) 3941{ 3942 return sock_has_perm(current, sock->sk, SOCKET__LISTEN); 3943} 3944 3945static int selinux_socket_accept(struct socket *sock, struct socket *newsock) 3946{ 3947 int err; 3948 struct inode_security_struct *isec; 3949 struct inode_security_struct *newisec; 3950 3951 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT); 3952 if (err) 3953 return err; 3954 3955 newisec = SOCK_INODE(newsock)->i_security; 3956 3957 isec = SOCK_INODE(sock)->i_security; 3958 newisec->sclass = isec->sclass; 3959 newisec->sid = isec->sid; 3960 newisec->initialized = 1; 3961 3962 return 0; 3963} 3964 3965static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg, 3966 int size) 3967{ 3968 return sock_has_perm(current, sock->sk, SOCKET__WRITE); 3969} 3970 3971static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg, 3972 int size, int flags) 3973{ 3974 return sock_has_perm(current, sock->sk, SOCKET__READ); 3975} 3976 3977static int selinux_socket_getsockname(struct socket *sock) 3978{ 3979 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 3980} 3981 3982static int selinux_socket_getpeername(struct socket *sock) 3983{ 3984 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 3985} 3986 3987static int selinux_socket_setsockopt(struct socket *sock, int level, int optname) 3988{ 3989 int err; 3990 3991 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT); 3992 if (err) 3993 return err; 3994 3995 return selinux_netlbl_socket_setsockopt(sock, level, optname); 3996} 3997 3998static int selinux_socket_getsockopt(struct socket *sock, int level, 3999 int optname) 4000{ 4001 return sock_has_perm(current, sock->sk, SOCKET__GETOPT); 4002} 4003 4004static int selinux_socket_shutdown(struct socket *sock, int how) 4005{ 4006 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN); 4007} 4008 4009static int selinux_socket_unix_stream_connect(struct sock *sock, 4010 struct sock *other, 4011 struct sock *newsk) 4012{ 4013 struct sk_security_struct *sksec_sock = sock->sk_security; 4014 struct sk_security_struct *sksec_other = other->sk_security; 4015 struct sk_security_struct *sksec_new = newsk->sk_security; 4016 struct common_audit_data ad; 4017 int err; 4018 4019 COMMON_AUDIT_DATA_INIT(&ad, NET); 4020 ad.u.net.sk = other; 4021 4022 err = avc_has_perm(sksec_sock->sid, sksec_other->sid, 4023 sksec_other->sclass, 4024 UNIX_STREAM_SOCKET__CONNECTTO, &ad); 4025 if (err) 4026 return err; 4027 4028 /* server child socket */ 4029 sksec_new->peer_sid = sksec_sock->sid; 4030 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid, 4031 &sksec_new->sid); 4032 if (err) 4033 return err; 4034 4035 /* connecting socket */ 4036 sksec_sock->peer_sid = sksec_new->sid; 4037 4038 return 0; 4039} 4040 4041static int selinux_socket_unix_may_send(struct socket *sock, 4042 struct socket *other) 4043{ 4044 struct sk_security_struct *ssec = sock->sk->sk_security; 4045 struct sk_security_struct *osec = other->sk->sk_security; 4046 struct common_audit_data ad; 4047 4048 COMMON_AUDIT_DATA_INIT(&ad, NET); 4049 ad.u.net.sk = other->sk; 4050 4051 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO, 4052 &ad); 4053} 4054 4055static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family, 4056 u32 peer_sid, 4057 struct common_audit_data *ad) 4058{ 4059 int err; 4060 u32 if_sid; 4061 u32 node_sid; 4062 4063 err = sel_netif_sid(ifindex, &if_sid); 4064 if (err) 4065 return err; 4066 err = avc_has_perm(peer_sid, if_sid, 4067 SECCLASS_NETIF, NETIF__INGRESS, ad); 4068 if (err) 4069 return err; 4070 4071 err = sel_netnode_sid(addrp, family, &node_sid); 4072 if (err) 4073 return err; 4074 return avc_has_perm(peer_sid, node_sid, 4075 SECCLASS_NODE, NODE__RECVFROM, ad); 4076} 4077 4078static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, 4079 u16 family) 4080{ 4081 int err = 0; 4082 struct sk_security_struct *sksec = sk->sk_security; 4083 u32 sk_sid = sksec->sid; 4084 struct common_audit_data ad; 4085 char *addrp; 4086 4087 COMMON_AUDIT_DATA_INIT(&ad, NET); 4088 ad.u.net.netif = skb->skb_iif; 4089 ad.u.net.family = family; 4090 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4091 if (err) 4092 return err; 4093 4094 if (selinux_secmark_enabled()) { 4095 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4096 PACKET__RECV, &ad); 4097 if (err) 4098 return err; 4099 } 4100 4101 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); 4102 if (err) 4103 return err; 4104 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); 4105 4106 return err; 4107} 4108 4109static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 4110{ 4111 int err; 4112 struct sk_security_struct *sksec = sk->sk_security; 4113 u16 family = sk->sk_family; 4114 u32 sk_sid = sksec->sid; 4115 struct common_audit_data ad; 4116 char *addrp; 4117 u8 secmark_active; 4118 u8 peerlbl_active; 4119 4120 if (family != PF_INET && family != PF_INET6) 4121 return 0; 4122 4123 /* Handle mapped IPv4 packets arriving via IPv6 sockets */ 4124 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4125 family = PF_INET; 4126 4127 /* If any sort of compatibility mode is enabled then handoff processing 4128 * to the selinux_sock_rcv_skb_compat() function to deal with the 4129 * special handling. We do this in an attempt to keep this function 4130 * as fast and as clean as possible. */ 4131 if (!selinux_policycap_netpeer) 4132 return selinux_sock_rcv_skb_compat(sk, skb, family); 4133 4134 secmark_active = selinux_secmark_enabled(); 4135 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4136 if (!secmark_active && !peerlbl_active) 4137 return 0; 4138 4139 COMMON_AUDIT_DATA_INIT(&ad, NET); 4140 ad.u.net.netif = skb->skb_iif; 4141 ad.u.net.family = family; 4142 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4143 if (err) 4144 return err; 4145 4146 if (peerlbl_active) { 4147 u32 peer_sid; 4148 4149 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); 4150 if (err) 4151 return err; 4152 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family, 4153 peer_sid, &ad); 4154 if (err) { 4155 selinux_netlbl_err(skb, err, 0); 4156 return err; 4157 } 4158 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, 4159 PEER__RECV, &ad); 4160 if (err) 4161 selinux_netlbl_err(skb, err, 0); 4162 } 4163 4164 if (secmark_active) { 4165 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4166 PACKET__RECV, &ad); 4167 if (err) 4168 return err; 4169 } 4170 4171 return err; 4172} 4173 4174static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval, 4175 int __user *optlen, unsigned len) 4176{ 4177 int err = 0; 4178 char *scontext; 4179 u32 scontext_len; 4180 struct sk_security_struct *sksec = sock->sk->sk_security; 4181 u32 peer_sid = SECSID_NULL; 4182 4183 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || 4184 sksec->sclass == SECCLASS_TCP_SOCKET) 4185 peer_sid = sksec->peer_sid; 4186 if (peer_sid == SECSID_NULL) 4187 return -ENOPROTOOPT; 4188 4189 err = security_sid_to_context(peer_sid, &scontext, &scontext_len); 4190 if (err) 4191 return err; 4192 4193 if (scontext_len > len) { 4194 err = -ERANGE; 4195 goto out_len; 4196 } 4197 4198 if (copy_to_user(optval, scontext, scontext_len)) 4199 err = -EFAULT; 4200 4201out_len: 4202 if (put_user(scontext_len, optlen)) 4203 err = -EFAULT; 4204 kfree(scontext); 4205 return err; 4206} 4207 4208static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) 4209{ 4210 u32 peer_secid = SECSID_NULL; 4211 u16 family; 4212 4213 if (skb && skb->protocol == htons(ETH_P_IP)) 4214 family = PF_INET; 4215 else if (skb && skb->protocol == htons(ETH_P_IPV6)) 4216 family = PF_INET6; 4217 else if (sock) 4218 family = sock->sk->sk_family; 4219 else 4220 goto out; 4221 4222 if (sock && family == PF_UNIX) 4223 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid); 4224 else if (skb) 4225 selinux_skb_peerlbl_sid(skb, family, &peer_secid); 4226 4227out: 4228 *secid = peer_secid; 4229 if (peer_secid == SECSID_NULL) 4230 return -EINVAL; 4231 return 0; 4232} 4233 4234static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) 4235{ 4236 struct sk_security_struct *sksec; 4237 4238 sksec = kzalloc(sizeof(*sksec), priority); 4239 if (!sksec) 4240 return -ENOMEM; 4241 4242 sksec->peer_sid = SECINITSID_UNLABELED; 4243 sksec->sid = SECINITSID_UNLABELED; 4244 selinux_netlbl_sk_security_reset(sksec); 4245 sk->sk_security = sksec; 4246 4247 return 0; 4248} 4249 4250static void selinux_sk_free_security(struct sock *sk) 4251{ 4252 struct sk_security_struct *sksec = sk->sk_security; 4253 4254 sk->sk_security = NULL; 4255 selinux_netlbl_sk_security_free(sksec); 4256 kfree(sksec); 4257} 4258 4259static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) 4260{ 4261 struct sk_security_struct *sksec = sk->sk_security; 4262 struct sk_security_struct *newsksec = newsk->sk_security; 4263 4264 newsksec->sid = sksec->sid; 4265 newsksec->peer_sid = sksec->peer_sid; 4266 newsksec->sclass = sksec->sclass; 4267 4268 selinux_netlbl_sk_security_reset(newsksec); 4269} 4270 4271static void selinux_sk_getsecid(struct sock *sk, u32 *secid) 4272{ 4273 if (!sk) 4274 *secid = SECINITSID_ANY_SOCKET; 4275 else { 4276 struct sk_security_struct *sksec = sk->sk_security; 4277 4278 *secid = sksec->sid; 4279 } 4280} 4281 4282static void selinux_sock_graft(struct sock *sk, struct socket *parent) 4283{ 4284 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security; 4285 struct sk_security_struct *sksec = sk->sk_security; 4286 4287 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || 4288 sk->sk_family == PF_UNIX) 4289 isec->sid = sksec->sid; 4290 sksec->sclass = isec->sclass; 4291} 4292 4293static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, 4294 struct request_sock *req) 4295{ 4296 struct sk_security_struct *sksec = sk->sk_security; 4297 int err; 4298 u16 family = sk->sk_family; 4299 u32 newsid; 4300 u32 peersid; 4301 4302 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4303 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4304 family = PF_INET; 4305 4306 err = selinux_skb_peerlbl_sid(skb, family, &peersid); 4307 if (err) 4308 return err; 4309 if (peersid == SECSID_NULL) { 4310 req->secid = sksec->sid; 4311 req->peer_secid = SECSID_NULL; 4312 } else { 4313 err = security_sid_mls_copy(sksec->sid, peersid, &newsid); 4314 if (err) 4315 return err; 4316 req->secid = newsid; 4317 req->peer_secid = peersid; 4318 } 4319 4320 return selinux_netlbl_inet_conn_request(req, family); 4321} 4322 4323static void selinux_inet_csk_clone(struct sock *newsk, 4324 const struct request_sock *req) 4325{ 4326 struct sk_security_struct *newsksec = newsk->sk_security; 4327 4328 newsksec->sid = req->secid; 4329 newsksec->peer_sid = req->peer_secid; 4330 /* NOTE: Ideally, we should also get the isec->sid for the 4331 new socket in sync, but we don't have the isec available yet. 4332 So we will wait until sock_graft to do it, by which 4333 time it will have been created and available. */ 4334 4335 /* We don't need to take any sort of lock here as we are the only 4336 * thread with access to newsksec */ 4337 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family); 4338} 4339 4340static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) 4341{ 4342 u16 family = sk->sk_family; 4343 struct sk_security_struct *sksec = sk->sk_security; 4344 4345 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4346 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4347 family = PF_INET; 4348 4349 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); 4350} 4351 4352static int selinux_secmark_relabel_packet(u32 sid) 4353{ 4354 const struct task_security_struct *__tsec; 4355 u32 tsid; 4356 4357 __tsec = current_security(); 4358 tsid = __tsec->sid; 4359 4360 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL); 4361} 4362 4363static void selinux_secmark_refcount_inc(void) 4364{ 4365 atomic_inc(&selinux_secmark_refcount); 4366} 4367 4368static void selinux_secmark_refcount_dec(void) 4369{ 4370 atomic_dec(&selinux_secmark_refcount); 4371} 4372 4373static void selinux_req_classify_flow(const struct request_sock *req, 4374 struct flowi *fl) 4375{ 4376 fl->flowi_secid = req->secid; 4377} 4378 4379static int selinux_tun_dev_create(void) 4380{ 4381 u32 sid = current_sid(); 4382 4383 /* we aren't taking into account the "sockcreate" SID since the socket 4384 * that is being created here is not a socket in the traditional sense, 4385 * instead it is a private sock, accessible only to the kernel, and 4386 * representing a wide range of network traffic spanning multiple 4387 * connections unlike traditional sockets - check the TUN driver to 4388 * get a better understanding of why this socket is special */ 4389 4390 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, 4391 NULL); 4392} 4393 4394static void selinux_tun_dev_post_create(struct sock *sk) 4395{ 4396 struct sk_security_struct *sksec = sk->sk_security; 4397 4398 /* we don't currently perform any NetLabel based labeling here and it 4399 * isn't clear that we would want to do so anyway; while we could apply 4400 * labeling without the support of the TUN user the resulting labeled 4401 * traffic from the other end of the connection would almost certainly 4402 * cause confusion to the TUN user that had no idea network labeling 4403 * protocols were being used */ 4404 4405 /* see the comments in selinux_tun_dev_create() about why we don't use 4406 * the sockcreate SID here */ 4407 4408 sksec->sid = current_sid(); 4409 sksec->sclass = SECCLASS_TUN_SOCKET; 4410} 4411 4412static int selinux_tun_dev_attach(struct sock *sk) 4413{ 4414 struct sk_security_struct *sksec = sk->sk_security; 4415 u32 sid = current_sid(); 4416 int err; 4417 4418 err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET, 4419 TUN_SOCKET__RELABELFROM, NULL); 4420 if (err) 4421 return err; 4422 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, 4423 TUN_SOCKET__RELABELTO, NULL); 4424 if (err) 4425 return err; 4426 4427 sksec->sid = sid; 4428 4429 return 0; 4430} 4431 4432static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb) 4433{ 4434 int err = 0; 4435 u32 perm; 4436 struct nlmsghdr *nlh; 4437 struct sk_security_struct *sksec = sk->sk_security; 4438 4439 if (skb->len < NLMSG_SPACE(0)) { 4440 err = -EINVAL; 4441 goto out; 4442 } 4443 nlh = nlmsg_hdr(skb); 4444 4445 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm); 4446 if (err) { 4447 if (err == -EINVAL) { 4448 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR, 4449 "SELinux: unrecognized netlink message" 4450 " type=%hu for sclass=%hu\n", 4451 nlh->nlmsg_type, sksec->sclass); 4452 if (!selinux_enforcing || security_get_allow_unknown()) 4453 err = 0; 4454 } 4455 4456 /* Ignore */ 4457 if (err == -ENOENT) 4458 err = 0; 4459 goto out; 4460 } 4461 4462 err = sock_has_perm(current, sk, perm); 4463out: 4464 return err; 4465} 4466 4467#ifdef CONFIG_NETFILTER 4468 4469static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, 4470 u16 family) 4471{ 4472 int err; 4473 char *addrp; 4474 u32 peer_sid; 4475 struct common_audit_data ad; 4476 u8 secmark_active; 4477 u8 netlbl_active; 4478 u8 peerlbl_active; 4479 4480 if (!selinux_policycap_netpeer) 4481 return NF_ACCEPT; 4482 4483 secmark_active = selinux_secmark_enabled(); 4484 netlbl_active = netlbl_enabled(); 4485 peerlbl_active = netlbl_active || selinux_xfrm_enabled(); 4486 if (!secmark_active && !peerlbl_active) 4487 return NF_ACCEPT; 4488 4489 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) 4490 return NF_DROP; 4491 4492 COMMON_AUDIT_DATA_INIT(&ad, NET); 4493 ad.u.net.netif = ifindex; 4494 ad.u.net.family = family; 4495 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) 4496 return NF_DROP; 4497 4498 if (peerlbl_active) { 4499 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family, 4500 peer_sid, &ad); 4501 if (err) { 4502 selinux_netlbl_err(skb, err, 1); 4503 return NF_DROP; 4504 } 4505 } 4506 4507 if (secmark_active) 4508 if (avc_has_perm(peer_sid, skb->secmark, 4509 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) 4510 return NF_DROP; 4511 4512 if (netlbl_active) 4513 /* we do this in the FORWARD path and not the POST_ROUTING 4514 * path because we want to make sure we apply the necessary 4515 * labeling before IPsec is applied so we can leverage AH 4516 * protection */ 4517 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) 4518 return NF_DROP; 4519 4520 return NF_ACCEPT; 4521} 4522 4523static unsigned int selinux_ipv4_forward(unsigned int hooknum, 4524 struct sk_buff *skb, 4525 const struct net_device *in, 4526 const struct net_device *out, 4527 int (*okfn)(struct sk_buff *)) 4528{ 4529 return selinux_ip_forward(skb, in->ifindex, PF_INET); 4530} 4531 4532#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4533static unsigned int selinux_ipv6_forward(unsigned int hooknum, 4534 struct sk_buff *skb, 4535 const struct net_device *in, 4536 const struct net_device *out, 4537 int (*okfn)(struct sk_buff *)) 4538{ 4539 return selinux_ip_forward(skb, in->ifindex, PF_INET6); 4540} 4541#endif /* IPV6 */ 4542 4543static unsigned int selinux_ip_output(struct sk_buff *skb, 4544 u16 family) 4545{ 4546 u32 sid; 4547 4548 if (!netlbl_enabled()) 4549 return NF_ACCEPT; 4550 4551 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path 4552 * because we want to make sure we apply the necessary labeling 4553 * before IPsec is applied so we can leverage AH protection */ 4554 if (skb->sk) { 4555 struct sk_security_struct *sksec = skb->sk->sk_security; 4556 sid = sksec->sid; 4557 } else 4558 sid = SECINITSID_KERNEL; 4559 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0) 4560 return NF_DROP; 4561 4562 return NF_ACCEPT; 4563} 4564 4565static unsigned int selinux_ipv4_output(unsigned int hooknum, 4566 struct sk_buff *skb, 4567 const struct net_device *in, 4568 const struct net_device *out, 4569 int (*okfn)(struct sk_buff *)) 4570{ 4571 return selinux_ip_output(skb, PF_INET); 4572} 4573 4574static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, 4575 int ifindex, 4576 u16 family) 4577{ 4578 struct sock *sk = skb->sk; 4579 struct sk_security_struct *sksec; 4580 struct common_audit_data ad; 4581 char *addrp; 4582 u8 proto; 4583 4584 if (sk == NULL) 4585 return NF_ACCEPT; 4586 sksec = sk->sk_security; 4587 4588 COMMON_AUDIT_DATA_INIT(&ad, NET); 4589 ad.u.net.netif = ifindex; 4590 ad.u.net.family = family; 4591 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto)) 4592 return NF_DROP; 4593 4594 if (selinux_secmark_enabled()) 4595 if (avc_has_perm(sksec->sid, skb->secmark, 4596 SECCLASS_PACKET, PACKET__SEND, &ad)) 4597 return NF_DROP_ERR(-ECONNREFUSED); 4598 4599 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) 4600 return NF_DROP_ERR(-ECONNREFUSED); 4601 4602 return NF_ACCEPT; 4603} 4604 4605static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, 4606 u16 family) 4607{ 4608 u32 secmark_perm; 4609 u32 peer_sid; 4610 struct sock *sk; 4611 struct common_audit_data ad; 4612 char *addrp; 4613 u8 secmark_active; 4614 u8 peerlbl_active; 4615 4616 /* If any sort of compatibility mode is enabled then handoff processing 4617 * to the selinux_ip_postroute_compat() function to deal with the 4618 * special handling. We do this in an attempt to keep this function 4619 * as fast and as clean as possible. */ 4620 if (!selinux_policycap_netpeer) 4621 return selinux_ip_postroute_compat(skb, ifindex, family); 4622#ifdef CONFIG_XFRM 4623 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec 4624 * packet transformation so allow the packet to pass without any checks 4625 * since we'll have another chance to perform access control checks 4626 * when the packet is on it's final way out. 4627 * NOTE: there appear to be some IPv6 multicast cases where skb->dst 4628 * is NULL, in this case go ahead and apply access control. */ 4629 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL) 4630 return NF_ACCEPT; 4631#endif 4632 secmark_active = selinux_secmark_enabled(); 4633 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4634 if (!secmark_active && !peerlbl_active) 4635 return NF_ACCEPT; 4636 4637 /* if the packet is being forwarded then get the peer label from the 4638 * packet itself; otherwise check to see if it is from a local 4639 * application or the kernel, if from an application get the peer label 4640 * from the sending socket, otherwise use the kernel's sid */ 4641 sk = skb->sk; 4642 if (sk == NULL) { 4643 if (skb->skb_iif) { 4644 secmark_perm = PACKET__FORWARD_OUT; 4645 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) 4646 return NF_DROP; 4647 } else { 4648 secmark_perm = PACKET__SEND; 4649 peer_sid = SECINITSID_KERNEL; 4650 } 4651 } else { 4652 struct sk_security_struct *sksec = sk->sk_security; 4653 peer_sid = sksec->sid; 4654 secmark_perm = PACKET__SEND; 4655 } 4656 4657 COMMON_AUDIT_DATA_INIT(&ad, NET); 4658 ad.u.net.netif = ifindex; 4659 ad.u.net.family = family; 4660 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) 4661 return NF_DROP; 4662 4663 if (secmark_active) 4664 if (avc_has_perm(peer_sid, skb->secmark, 4665 SECCLASS_PACKET, secmark_perm, &ad)) 4666 return NF_DROP_ERR(-ECONNREFUSED); 4667 4668 if (peerlbl_active) { 4669 u32 if_sid; 4670 u32 node_sid; 4671 4672 if (sel_netif_sid(ifindex, &if_sid)) 4673 return NF_DROP; 4674 if (avc_has_perm(peer_sid, if_sid, 4675 SECCLASS_NETIF, NETIF__EGRESS, &ad)) 4676 return NF_DROP_ERR(-ECONNREFUSED); 4677 4678 if (sel_netnode_sid(addrp, family, &node_sid)) 4679 return NF_DROP; 4680 if (avc_has_perm(peer_sid, node_sid, 4681 SECCLASS_NODE, NODE__SENDTO, &ad)) 4682 return NF_DROP_ERR(-ECONNREFUSED); 4683 } 4684 4685 return NF_ACCEPT; 4686} 4687 4688static unsigned int selinux_ipv4_postroute(unsigned int hooknum, 4689 struct sk_buff *skb, 4690 const struct net_device *in, 4691 const struct net_device *out, 4692 int (*okfn)(struct sk_buff *)) 4693{ 4694 return selinux_ip_postroute(skb, out->ifindex, PF_INET); 4695} 4696 4697#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4698static unsigned int selinux_ipv6_postroute(unsigned int hooknum, 4699 struct sk_buff *skb, 4700 const struct net_device *in, 4701 const struct net_device *out, 4702 int (*okfn)(struct sk_buff *)) 4703{ 4704 return selinux_ip_postroute(skb, out->ifindex, PF_INET6); 4705} 4706#endif /* IPV6 */ 4707 4708#endif /* CONFIG_NETFILTER */ 4709 4710static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) 4711{ 4712 int err; 4713 4714 err = cap_netlink_send(sk, skb); 4715 if (err) 4716 return err; 4717 4718 return selinux_nlmsg_perm(sk, skb); 4719} 4720 4721static int selinux_netlink_recv(struct sk_buff *skb, int capability) 4722{ 4723 int err; 4724 struct common_audit_data ad; 4725 u32 sid; 4726 4727 err = cap_netlink_recv(skb, capability); 4728 if (err) 4729 return err; 4730 4731 COMMON_AUDIT_DATA_INIT(&ad, CAP); 4732 ad.u.cap = capability; 4733 4734 security_task_getsecid(current, &sid); 4735 return avc_has_perm(sid, sid, SECCLASS_CAPABILITY, 4736 CAP_TO_MASK(capability), &ad); 4737} 4738 4739static int ipc_alloc_security(struct task_struct *task, 4740 struct kern_ipc_perm *perm, 4741 u16 sclass) 4742{ 4743 struct ipc_security_struct *isec; 4744 u32 sid; 4745 4746 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); 4747 if (!isec) 4748 return -ENOMEM; 4749 4750 sid = task_sid(task); 4751 isec->sclass = sclass; 4752 isec->sid = sid; 4753 perm->security = isec; 4754 4755 return 0; 4756} 4757 4758static void ipc_free_security(struct kern_ipc_perm *perm) 4759{ 4760 struct ipc_security_struct *isec = perm->security; 4761 perm->security = NULL; 4762 kfree(isec); 4763} 4764 4765static int msg_msg_alloc_security(struct msg_msg *msg) 4766{ 4767 struct msg_security_struct *msec; 4768 4769 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL); 4770 if (!msec) 4771 return -ENOMEM; 4772 4773 msec->sid = SECINITSID_UNLABELED; 4774 msg->security = msec; 4775 4776 return 0; 4777} 4778 4779static void msg_msg_free_security(struct msg_msg *msg) 4780{ 4781 struct msg_security_struct *msec = msg->security; 4782 4783 msg->security = NULL; 4784 kfree(msec); 4785} 4786 4787static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, 4788 u32 perms) 4789{ 4790 struct ipc_security_struct *isec; 4791 struct common_audit_data ad; 4792 u32 sid = current_sid(); 4793 4794 isec = ipc_perms->security; 4795 4796 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4797 ad.u.ipc_id = ipc_perms->key; 4798 4799 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad); 4800} 4801 4802static int selinux_msg_msg_alloc_security(struct msg_msg *msg) 4803{ 4804 return msg_msg_alloc_security(msg); 4805} 4806 4807static void selinux_msg_msg_free_security(struct msg_msg *msg) 4808{ 4809 msg_msg_free_security(msg); 4810} 4811 4812/* message queue security operations */ 4813static int selinux_msg_queue_alloc_security(struct msg_queue *msq) 4814{ 4815 struct ipc_security_struct *isec; 4816 struct common_audit_data ad; 4817 u32 sid = current_sid(); 4818 int rc; 4819 4820 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ); 4821 if (rc) 4822 return rc; 4823 4824 isec = msq->q_perm.security; 4825 4826 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4827 ad.u.ipc_id = msq->q_perm.key; 4828 4829 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4830 MSGQ__CREATE, &ad); 4831 if (rc) { 4832 ipc_free_security(&msq->q_perm); 4833 return rc; 4834 } 4835 return 0; 4836} 4837 4838static void selinux_msg_queue_free_security(struct msg_queue *msq) 4839{ 4840 ipc_free_security(&msq->q_perm); 4841} 4842 4843static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg) 4844{ 4845 struct ipc_security_struct *isec; 4846 struct common_audit_data ad; 4847 u32 sid = current_sid(); 4848 4849 isec = msq->q_perm.security; 4850 4851 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4852 ad.u.ipc_id = msq->q_perm.key; 4853 4854 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4855 MSGQ__ASSOCIATE, &ad); 4856} 4857 4858static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd) 4859{ 4860 int err; 4861 int perms; 4862 4863 switch (cmd) { 4864 case IPC_INFO: 4865 case MSG_INFO: 4866 /* No specific object, just general system-wide information. */ 4867 return task_has_system(current, SYSTEM__IPC_INFO); 4868 case IPC_STAT: 4869 case MSG_STAT: 4870 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE; 4871 break; 4872 case IPC_SET: 4873 perms = MSGQ__SETATTR; 4874 break; 4875 case IPC_RMID: 4876 perms = MSGQ__DESTROY; 4877 break; 4878 default: 4879 return 0; 4880 } 4881 4882 err = ipc_has_perm(&msq->q_perm, perms); 4883 return err; 4884} 4885 4886static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg) 4887{ 4888 struct ipc_security_struct *isec; 4889 struct msg_security_struct *msec; 4890 struct common_audit_data ad; 4891 u32 sid = current_sid(); 4892 int rc; 4893 4894 isec = msq->q_perm.security; 4895 msec = msg->security; 4896 4897 /* 4898 * First time through, need to assign label to the message 4899 */ 4900 if (msec->sid == SECINITSID_UNLABELED) { 4901 /* 4902 * Compute new sid based on current process and 4903 * message queue this message will be stored in 4904 */ 4905 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG, 4906 NULL, &msec->sid); 4907 if (rc) 4908 return rc; 4909 } 4910 4911 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4912 ad.u.ipc_id = msq->q_perm.key; 4913 4914 /* Can this process write to the queue? */ 4915 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4916 MSGQ__WRITE, &ad); 4917 if (!rc) 4918 /* Can this process send the message */ 4919 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG, 4920 MSG__SEND, &ad); 4921 if (!rc) 4922 /* Can the message be put in the queue? */ 4923 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ, 4924 MSGQ__ENQUEUE, &ad); 4925 4926 return rc; 4927} 4928 4929static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 4930 struct task_struct *target, 4931 long type, int mode) 4932{ 4933 struct ipc_security_struct *isec; 4934 struct msg_security_struct *msec; 4935 struct common_audit_data ad; 4936 u32 sid = task_sid(target); 4937 int rc; 4938 4939 isec = msq->q_perm.security; 4940 msec = msg->security; 4941 4942 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4943 ad.u.ipc_id = msq->q_perm.key; 4944 4945 rc = avc_has_perm(sid, isec->sid, 4946 SECCLASS_MSGQ, MSGQ__READ, &ad); 4947 if (!rc) 4948 rc = avc_has_perm(sid, msec->sid, 4949 SECCLASS_MSG, MSG__RECEIVE, &ad); 4950 return rc; 4951} 4952 4953/* Shared Memory security operations */ 4954static int selinux_shm_alloc_security(struct shmid_kernel *shp) 4955{ 4956 struct ipc_security_struct *isec; 4957 struct common_audit_data ad; 4958 u32 sid = current_sid(); 4959 int rc; 4960 4961 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM); 4962 if (rc) 4963 return rc; 4964 4965 isec = shp->shm_perm.security; 4966 4967 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4968 ad.u.ipc_id = shp->shm_perm.key; 4969 4970 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM, 4971 SHM__CREATE, &ad); 4972 if (rc) { 4973 ipc_free_security(&shp->shm_perm); 4974 return rc; 4975 } 4976 return 0; 4977} 4978 4979static void selinux_shm_free_security(struct shmid_kernel *shp) 4980{ 4981 ipc_free_security(&shp->shm_perm); 4982} 4983 4984static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg) 4985{ 4986 struct ipc_security_struct *isec; 4987 struct common_audit_data ad; 4988 u32 sid = current_sid(); 4989 4990 isec = shp->shm_perm.security; 4991 4992 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4993 ad.u.ipc_id = shp->shm_perm.key; 4994 4995 return avc_has_perm(sid, isec->sid, SECCLASS_SHM, 4996 SHM__ASSOCIATE, &ad); 4997} 4998 4999/* Note, at this point, shp is locked down */ 5000static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd) 5001{ 5002 int perms; 5003 int err; 5004 5005 switch (cmd) { 5006 case IPC_INFO: 5007 case SHM_INFO: 5008 /* No specific object, just general system-wide information. */ 5009 return task_has_system(current, SYSTEM__IPC_INFO); 5010 case IPC_STAT: 5011 case SHM_STAT: 5012 perms = SHM__GETATTR | SHM__ASSOCIATE; 5013 break; 5014 case IPC_SET: 5015 perms = SHM__SETATTR; 5016 break; 5017 case SHM_LOCK: 5018 case SHM_UNLOCK: 5019 perms = SHM__LOCK; 5020 break; 5021 case IPC_RMID: 5022 perms = SHM__DESTROY; 5023 break; 5024 default: 5025 return 0; 5026 } 5027 5028 err = ipc_has_perm(&shp->shm_perm, perms); 5029 return err; 5030} 5031 5032static int selinux_shm_shmat(struct shmid_kernel *shp, 5033 char __user *shmaddr, int shmflg) 5034{ 5035 u32 perms; 5036 5037 if (shmflg & SHM_RDONLY) 5038 perms = SHM__READ; 5039 else 5040 perms = SHM__READ | SHM__WRITE; 5041 5042 return ipc_has_perm(&shp->shm_perm, perms); 5043} 5044 5045/* Semaphore security operations */ 5046static int selinux_sem_alloc_security(struct sem_array *sma) 5047{ 5048 struct ipc_security_struct *isec; 5049 struct common_audit_data ad; 5050 u32 sid = current_sid(); 5051 int rc; 5052 5053 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM); 5054 if (rc) 5055 return rc; 5056 5057 isec = sma->sem_perm.security; 5058 5059 COMMON_AUDIT_DATA_INIT(&ad, IPC); 5060 ad.u.ipc_id = sma->sem_perm.key; 5061 5062 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5063 SEM__CREATE, &ad); 5064 if (rc) { 5065 ipc_free_security(&sma->sem_perm); 5066 return rc; 5067 } 5068 return 0; 5069} 5070 5071static void selinux_sem_free_security(struct sem_array *sma) 5072{ 5073 ipc_free_security(&sma->sem_perm); 5074} 5075 5076static int selinux_sem_associate(struct sem_array *sma, int semflg) 5077{ 5078 struct ipc_security_struct *isec; 5079 struct common_audit_data ad; 5080 u32 sid = current_sid(); 5081 5082 isec = sma->sem_perm.security; 5083 5084 COMMON_AUDIT_DATA_INIT(&ad, IPC); 5085 ad.u.ipc_id = sma->sem_perm.key; 5086 5087 return avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5088 SEM__ASSOCIATE, &ad); 5089} 5090 5091/* Note, at this point, sma is locked down */ 5092static int selinux_sem_semctl(struct sem_array *sma, int cmd) 5093{ 5094 int err; 5095 u32 perms; 5096 5097 switch (cmd) { 5098 case IPC_INFO: 5099 case SEM_INFO: 5100 /* No specific object, just general system-wide information. */ 5101 return task_has_system(current, SYSTEM__IPC_INFO); 5102 case GETPID: 5103 case GETNCNT: 5104 case GETZCNT: 5105 perms = SEM__GETATTR; 5106 break; 5107 case GETVAL: 5108 case GETALL: 5109 perms = SEM__READ; 5110 break; 5111 case SETVAL: 5112 case SETALL: 5113 perms = SEM__WRITE; 5114 break; 5115 case IPC_RMID: 5116 perms = SEM__DESTROY; 5117 break; 5118 case IPC_SET: 5119 perms = SEM__SETATTR; 5120 break; 5121 case IPC_STAT: 5122 case SEM_STAT: 5123 perms = SEM__GETATTR | SEM__ASSOCIATE; 5124 break; 5125 default: 5126 return 0; 5127 } 5128 5129 err = ipc_has_perm(&sma->sem_perm, perms); 5130 return err; 5131} 5132 5133static int selinux_sem_semop(struct sem_array *sma, 5134 struct sembuf *sops, unsigned nsops, int alter) 5135{ 5136 u32 perms; 5137 5138 if (alter) 5139 perms = SEM__READ | SEM__WRITE; 5140 else 5141 perms = SEM__READ; 5142 5143 return ipc_has_perm(&sma->sem_perm, perms); 5144} 5145 5146static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag) 5147{ 5148 u32 av = 0; 5149 5150 av = 0; 5151 if (flag & S_IRUGO) 5152 av |= IPC__UNIX_READ; 5153 if (flag & S_IWUGO) 5154 av |= IPC__UNIX_WRITE; 5155 5156 if (av == 0) 5157 return 0; 5158 5159 return ipc_has_perm(ipcp, av); 5160} 5161 5162static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) 5163{ 5164 struct ipc_security_struct *isec = ipcp->security; 5165 *secid = isec->sid; 5166} 5167 5168static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) 5169{ 5170 if (inode) 5171 inode_doinit_with_dentry(inode, dentry); 5172} 5173 5174static int selinux_getprocattr(struct task_struct *p, 5175 char *name, char **value) 5176{ 5177 const struct task_security_struct *__tsec; 5178 u32 sid; 5179 int error; 5180 unsigned len; 5181 5182 if (current != p) { 5183 error = current_has_perm(p, PROCESS__GETATTR); 5184 if (error) 5185 return error; 5186 } 5187 5188 rcu_read_lock(); 5189 __tsec = __task_cred(p)->security; 5190 5191 if (!strcmp(name, "current")) 5192 sid = __tsec->sid; 5193 else if (!strcmp(name, "prev")) 5194 sid = __tsec->osid; 5195 else if (!strcmp(name, "exec")) 5196 sid = __tsec->exec_sid; 5197 else if (!strcmp(name, "fscreate")) 5198 sid = __tsec->create_sid; 5199 else if (!strcmp(name, "keycreate")) 5200 sid = __tsec->keycreate_sid; 5201 else if (!strcmp(name, "sockcreate")) 5202 sid = __tsec->sockcreate_sid; 5203 else 5204 goto invalid; 5205 rcu_read_unlock(); 5206 5207 if (!sid) 5208 return 0; 5209 5210 error = security_sid_to_context(sid, value, &len); 5211 if (error) 5212 return error; 5213 return len; 5214 5215invalid: 5216 rcu_read_unlock(); 5217 return -EINVAL; 5218} 5219 5220static int selinux_setprocattr(struct task_struct *p, 5221 char *name, void *value, size_t size) 5222{ 5223 struct task_security_struct *tsec; 5224 struct task_struct *tracer; 5225 struct cred *new; 5226 u32 sid = 0, ptsid; 5227 int error; 5228 char *str = value; 5229 5230 if (current != p) { 5231 /* SELinux only allows a process to change its own 5232 security attributes. */ 5233 return -EACCES; 5234 } 5235 5236 /* 5237 * Basic control over ability to set these attributes at all. 5238 * current == p, but we'll pass them separately in case the 5239 * above restriction is ever removed. 5240 */ 5241 if (!strcmp(name, "exec")) 5242 error = current_has_perm(p, PROCESS__SETEXEC); 5243 else if (!strcmp(name, "fscreate")) 5244 error = current_has_perm(p, PROCESS__SETFSCREATE); 5245 else if (!strcmp(name, "keycreate")) 5246 error = current_has_perm(p, PROCESS__SETKEYCREATE); 5247 else if (!strcmp(name, "sockcreate")) 5248 error = current_has_perm(p, PROCESS__SETSOCKCREATE); 5249 else if (!strcmp(name, "current")) 5250 error = current_has_perm(p, PROCESS__SETCURRENT); 5251 else 5252 error = -EINVAL; 5253 if (error) 5254 return error; 5255 5256 /* Obtain a SID for the context, if one was specified. */ 5257 if (size && str[1] && str[1] != '\n') { 5258 if (str[size-1] == '\n') { 5259 str[size-1] = 0; 5260 size--; 5261 } 5262 error = security_context_to_sid(value, size, &sid); 5263 if (error == -EINVAL && !strcmp(name, "fscreate")) { 5264 if (!capable(CAP_MAC_ADMIN)) 5265 return error; 5266 error = security_context_to_sid_force(value, size, 5267 &sid); 5268 } 5269 if (error) 5270 return error; 5271 } 5272 5273 new = prepare_creds(); 5274 if (!new) 5275 return -ENOMEM; 5276 5277 /* Permission checking based on the specified context is 5278 performed during the actual operation (execve, 5279 open/mkdir/...), when we know the full context of the 5280 operation. See selinux_bprm_set_creds for the execve 5281 checks and may_create for the file creation checks. The 5282 operation will then fail if the context is not permitted. */ 5283 tsec = new->security; 5284 if (!strcmp(name, "exec")) { 5285 tsec->exec_sid = sid; 5286 } else if (!strcmp(name, "fscreate")) { 5287 tsec->create_sid = sid; 5288 } else if (!strcmp(name, "keycreate")) { 5289 error = may_create_key(sid, p); 5290 if (error) 5291 goto abort_change; 5292 tsec->keycreate_sid = sid; 5293 } else if (!strcmp(name, "sockcreate")) { 5294 tsec->sockcreate_sid = sid; 5295 } else if (!strcmp(name, "current")) { 5296 error = -EINVAL; 5297 if (sid == 0) 5298 goto abort_change; 5299 5300 /* Only allow single threaded processes to change context */ 5301 error = -EPERM; 5302 if (!current_is_single_threaded()) { 5303 error = security_bounded_transition(tsec->sid, sid); 5304 if (error) 5305 goto abort_change; 5306 } 5307 5308 /* Check permissions for the transition. */ 5309 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, 5310 PROCESS__DYNTRANSITION, NULL); 5311 if (error) 5312 goto abort_change; 5313 5314 /* Check for ptracing, and update the task SID if ok. 5315 Otherwise, leave SID unchanged and fail. */ 5316 ptsid = 0; 5317 task_lock(p); 5318 tracer = ptrace_parent(p); 5319 if (tracer) 5320 ptsid = task_sid(tracer); 5321 task_unlock(p); 5322 5323 if (tracer) { 5324 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, 5325 PROCESS__PTRACE, NULL); 5326 if (error) 5327 goto abort_change; 5328 } 5329 5330 tsec->sid = sid; 5331 } else { 5332 error = -EINVAL; 5333 goto abort_change; 5334 } 5335 5336 commit_creds(new); 5337 return size; 5338 5339abort_change: 5340 abort_creds(new); 5341 return error; 5342} 5343 5344static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 5345{ 5346 return security_sid_to_context(secid, secdata, seclen); 5347} 5348 5349static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 5350{ 5351 return security_context_to_sid(secdata, seclen, secid); 5352} 5353 5354static void selinux_release_secctx(char *secdata, u32 seclen) 5355{ 5356 kfree(secdata); 5357} 5358 5359/* 5360 * called with inode->i_mutex locked 5361 */ 5362static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 5363{ 5364 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0); 5365} 5366 5367/* 5368 * called with inode->i_mutex locked 5369 */ 5370static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 5371{ 5372 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0); 5373} 5374 5375static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 5376{ 5377 int len = 0; 5378 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX, 5379 ctx, true); 5380 if (len < 0) 5381 return len; 5382 *ctxlen = len; 5383 return 0; 5384} 5385#ifdef CONFIG_KEYS 5386 5387static int selinux_key_alloc(struct key *k, const struct cred *cred, 5388 unsigned long flags) 5389{ 5390 const struct task_security_struct *tsec; 5391 struct key_security_struct *ksec; 5392 5393 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); 5394 if (!ksec) 5395 return -ENOMEM; 5396 5397 tsec = cred->security; 5398 if (tsec->keycreate_sid) 5399 ksec->sid = tsec->keycreate_sid; 5400 else 5401 ksec->sid = tsec->sid; 5402 5403 k->security = ksec; 5404 return 0; 5405} 5406 5407static void selinux_key_free(struct key *k) 5408{ 5409 struct key_security_struct *ksec = k->security; 5410 5411 k->security = NULL; 5412 kfree(ksec); 5413} 5414 5415static int selinux_key_permission(key_ref_t key_ref, 5416 const struct cred *cred, 5417 key_perm_t perm) 5418{ 5419 struct key *key; 5420 struct key_security_struct *ksec; 5421 u32 sid; 5422 5423 /* if no specific permissions are requested, we skip the 5424 permission check. No serious, additional covert channels 5425 appear to be created. */ 5426 if (perm == 0) 5427 return 0; 5428 5429 sid = cred_sid(cred); 5430 5431 key = key_ref_to_ptr(key_ref); 5432 ksec = key->security; 5433 5434 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL); 5435} 5436 5437static int selinux_key_getsecurity(struct key *key, char **_buffer) 5438{ 5439 struct key_security_struct *ksec = key->security; 5440 char *context = NULL; 5441 unsigned len; 5442 int rc; 5443 5444 rc = security_sid_to_context(ksec->sid, &context, &len); 5445 if (!rc) 5446 rc = len; 5447 *_buffer = context; 5448 return rc; 5449} 5450 5451#endif 5452 5453static struct security_operations selinux_ops = { 5454 .name = "selinux", 5455 5456 .ptrace_access_check = selinux_ptrace_access_check, 5457 .ptrace_traceme = selinux_ptrace_traceme, 5458 .capget = selinux_capget, 5459 .capset = selinux_capset, 5460 .capable = selinux_capable, 5461 .quotactl = selinux_quotactl, 5462 .quota_on = selinux_quota_on, 5463 .syslog = selinux_syslog, 5464 .vm_enough_memory = selinux_vm_enough_memory, 5465 5466 .netlink_send = selinux_netlink_send, 5467 .netlink_recv = selinux_netlink_recv, 5468 5469 .bprm_set_creds = selinux_bprm_set_creds, 5470 .bprm_committing_creds = selinux_bprm_committing_creds, 5471 .bprm_committed_creds = selinux_bprm_committed_creds, 5472 .bprm_secureexec = selinux_bprm_secureexec, 5473 5474 .sb_alloc_security = selinux_sb_alloc_security, 5475 .sb_free_security = selinux_sb_free_security, 5476 .sb_copy_data = selinux_sb_copy_data, 5477 .sb_remount = selinux_sb_remount, 5478 .sb_kern_mount = selinux_sb_kern_mount, 5479 .sb_show_options = selinux_sb_show_options, 5480 .sb_statfs = selinux_sb_statfs, 5481 .sb_mount = selinux_mount, 5482 .sb_umount = selinux_umount, 5483 .sb_set_mnt_opts = selinux_set_mnt_opts, 5484 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, 5485 .sb_parse_opts_str = selinux_parse_opts_str, 5486 5487 5488 .inode_alloc_security = selinux_inode_alloc_security, 5489 .inode_free_security = selinux_inode_free_security, 5490 .inode_init_security = selinux_inode_init_security, 5491 .inode_create = selinux_inode_create, 5492 .inode_link = selinux_inode_link, 5493 .inode_unlink = selinux_inode_unlink, 5494 .inode_symlink = selinux_inode_symlink, 5495 .inode_mkdir = selinux_inode_mkdir, 5496 .inode_rmdir = selinux_inode_rmdir, 5497 .inode_mknod = selinux_inode_mknod, 5498 .inode_rename = selinux_inode_rename, 5499 .inode_readlink = selinux_inode_readlink, 5500 .inode_follow_link = selinux_inode_follow_link, 5501 .inode_permission = selinux_inode_permission, 5502 .inode_setattr = selinux_inode_setattr, 5503 .inode_getattr = selinux_inode_getattr, 5504 .inode_setxattr = selinux_inode_setxattr, 5505 .inode_post_setxattr = selinux_inode_post_setxattr, 5506 .inode_getxattr = selinux_inode_getxattr, 5507 .inode_listxattr = selinux_inode_listxattr, 5508 .inode_removexattr = selinux_inode_removexattr, 5509 .inode_getsecurity = selinux_inode_getsecurity, 5510 .inode_setsecurity = selinux_inode_setsecurity, 5511 .inode_listsecurity = selinux_inode_listsecurity, 5512 .inode_getsecid = selinux_inode_getsecid, 5513 5514 .file_permission = selinux_file_permission, 5515 .file_alloc_security = selinux_file_alloc_security, 5516 .file_free_security = selinux_file_free_security, 5517 .file_ioctl = selinux_file_ioctl, 5518 .file_mmap = selinux_file_mmap, 5519 .file_mprotect = selinux_file_mprotect, 5520 .file_lock = selinux_file_lock, 5521 .file_fcntl = selinux_file_fcntl, 5522 .file_set_fowner = selinux_file_set_fowner, 5523 .file_send_sigiotask = selinux_file_send_sigiotask, 5524 .file_receive = selinux_file_receive, 5525 5526 .dentry_open = selinux_dentry_open, 5527 5528 .task_create = selinux_task_create, 5529 .cred_alloc_blank = selinux_cred_alloc_blank, 5530 .cred_free = selinux_cred_free, 5531 .cred_prepare = selinux_cred_prepare, 5532 .cred_transfer = selinux_cred_transfer, 5533 .kernel_act_as = selinux_kernel_act_as, 5534 .kernel_create_files_as = selinux_kernel_create_files_as, 5535 .kernel_module_request = selinux_kernel_module_request, 5536 .task_setpgid = selinux_task_setpgid, 5537 .task_getpgid = selinux_task_getpgid, 5538 .task_getsid = selinux_task_getsid, 5539 .task_getsecid = selinux_task_getsecid, 5540 .task_setnice = selinux_task_setnice, 5541 .task_setioprio = selinux_task_setioprio, 5542 .task_getioprio = selinux_task_getioprio, 5543 .task_setrlimit = selinux_task_setrlimit, 5544 .task_setscheduler = selinux_task_setscheduler, 5545 .task_getscheduler = selinux_task_getscheduler, 5546 .task_movememory = selinux_task_movememory, 5547 .task_kill = selinux_task_kill, 5548 .task_wait = selinux_task_wait, 5549 .task_to_inode = selinux_task_to_inode, 5550 5551 .ipc_permission = selinux_ipc_permission, 5552 .ipc_getsecid = selinux_ipc_getsecid, 5553 5554 .msg_msg_alloc_security = selinux_msg_msg_alloc_security, 5555 .msg_msg_free_security = selinux_msg_msg_free_security, 5556 5557 .msg_queue_alloc_security = selinux_msg_queue_alloc_security, 5558 .msg_queue_free_security = selinux_msg_queue_free_security, 5559 .msg_queue_associate = selinux_msg_queue_associate, 5560 .msg_queue_msgctl = selinux_msg_queue_msgctl, 5561 .msg_queue_msgsnd = selinux_msg_queue_msgsnd, 5562 .msg_queue_msgrcv = selinux_msg_queue_msgrcv, 5563 5564 .shm_alloc_security = selinux_shm_alloc_security, 5565 .shm_free_security = selinux_shm_free_security, 5566 .shm_associate = selinux_shm_associate, 5567 .shm_shmctl = selinux_shm_shmctl, 5568 .shm_shmat = selinux_shm_shmat, 5569 5570 .sem_alloc_security = selinux_sem_alloc_security, 5571 .sem_free_security = selinux_sem_free_security, 5572 .sem_associate = selinux_sem_associate, 5573 .sem_semctl = selinux_sem_semctl, 5574 .sem_semop = selinux_sem_semop, 5575 5576 .d_instantiate = selinux_d_instantiate, 5577 5578 .getprocattr = selinux_getprocattr, 5579 .setprocattr = selinux_setprocattr, 5580 5581 .secid_to_secctx = selinux_secid_to_secctx, 5582 .secctx_to_secid = selinux_secctx_to_secid, 5583 .release_secctx = selinux_release_secctx, 5584 .inode_notifysecctx = selinux_inode_notifysecctx, 5585 .inode_setsecctx = selinux_inode_setsecctx, 5586 .inode_getsecctx = selinux_inode_getsecctx, 5587 5588 .unix_stream_connect = selinux_socket_unix_stream_connect, 5589 .unix_may_send = selinux_socket_unix_may_send, 5590 5591 .socket_create = selinux_socket_create, 5592 .socket_post_create = selinux_socket_post_create, 5593 .socket_bind = selinux_socket_bind, 5594 .socket_connect = selinux_socket_connect, 5595 .socket_listen = selinux_socket_listen, 5596 .socket_accept = selinux_socket_accept, 5597 .socket_sendmsg = selinux_socket_sendmsg, 5598 .socket_recvmsg = selinux_socket_recvmsg, 5599 .socket_getsockname = selinux_socket_getsockname, 5600 .socket_getpeername = selinux_socket_getpeername, 5601 .socket_getsockopt = selinux_socket_getsockopt, 5602 .socket_setsockopt = selinux_socket_setsockopt, 5603 .socket_shutdown = selinux_socket_shutdown, 5604 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb, 5605 .socket_getpeersec_stream = selinux_socket_getpeersec_stream, 5606 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram, 5607 .sk_alloc_security = selinux_sk_alloc_security, 5608 .sk_free_security = selinux_sk_free_security, 5609 .sk_clone_security = selinux_sk_clone_security, 5610 .sk_getsecid = selinux_sk_getsecid, 5611 .sock_graft = selinux_sock_graft, 5612 .inet_conn_request = selinux_inet_conn_request, 5613 .inet_csk_clone = selinux_inet_csk_clone, 5614 .inet_conn_established = selinux_inet_conn_established, 5615 .secmark_relabel_packet = selinux_secmark_relabel_packet, 5616 .secmark_refcount_inc = selinux_secmark_refcount_inc, 5617 .secmark_refcount_dec = selinux_secmark_refcount_dec, 5618 .req_classify_flow = selinux_req_classify_flow, 5619 .tun_dev_create = selinux_tun_dev_create, 5620 .tun_dev_post_create = selinux_tun_dev_post_create, 5621 .tun_dev_attach = selinux_tun_dev_attach, 5622 5623#ifdef CONFIG_SECURITY_NETWORK_XFRM 5624 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc, 5625 .xfrm_policy_clone_security = selinux_xfrm_policy_clone, 5626 .xfrm_policy_free_security = selinux_xfrm_policy_free, 5627 .xfrm_policy_delete_security = selinux_xfrm_policy_delete, 5628 .xfrm_state_alloc_security = selinux_xfrm_state_alloc, 5629 .xfrm_state_free_security = selinux_xfrm_state_free, 5630 .xfrm_state_delete_security = selinux_xfrm_state_delete, 5631 .xfrm_policy_lookup = selinux_xfrm_policy_lookup, 5632 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match, 5633 .xfrm_decode_session = selinux_xfrm_decode_session, 5634#endif 5635 5636#ifdef CONFIG_KEYS 5637 .key_alloc = selinux_key_alloc, 5638 .key_free = selinux_key_free, 5639 .key_permission = selinux_key_permission, 5640 .key_getsecurity = selinux_key_getsecurity, 5641#endif 5642 5643#ifdef CONFIG_AUDIT 5644 .audit_rule_init = selinux_audit_rule_init, 5645 .audit_rule_known = selinux_audit_rule_known, 5646 .audit_rule_match = selinux_audit_rule_match, 5647 .audit_rule_free = selinux_audit_rule_free, 5648#endif 5649}; 5650 5651static __init int selinux_init(void) 5652{ 5653 if (!security_module_enable(&selinux_ops)) { 5654 selinux_enabled = 0; 5655 return 0; 5656 } 5657 5658 if (!selinux_enabled) { 5659 printk(KERN_INFO "SELinux: Disabled at boot.\n"); 5660 return 0; 5661 } 5662 5663 printk(KERN_INFO "SELinux: Initializing.\n"); 5664 5665 /* Set the security state for the initial task. */ 5666 cred_init_security(); 5667 5668 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); 5669 5670 sel_inode_cache = kmem_cache_create("selinux_inode_security", 5671 sizeof(struct inode_security_struct), 5672 0, SLAB_PANIC, NULL); 5673 avc_init(); 5674 5675 if (register_security(&selinux_ops)) 5676 panic("SELinux: Unable to register with kernel.\n"); 5677 5678 if (selinux_enforcing) 5679 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n"); 5680 else 5681 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n"); 5682 5683 return 0; 5684} 5685 5686static void delayed_superblock_init(struct super_block *sb, void *unused) 5687{ 5688 superblock_doinit(sb, NULL); 5689} 5690 5691void selinux_complete_init(void) 5692{ 5693 printk(KERN_DEBUG "SELinux: Completing initialization.\n"); 5694 5695 /* Set up any superblocks initialized prior to the policy load. */ 5696 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n"); 5697 iterate_supers(delayed_superblock_init, NULL); 5698} 5699 5700/* SELinux requires early initialization in order to label 5701 all processes and objects when they are created. */ 5702security_initcall(selinux_init); 5703 5704#if defined(CONFIG_NETFILTER) 5705 5706static struct nf_hook_ops selinux_ipv4_ops[] = { 5707 { 5708 .hook = selinux_ipv4_postroute, 5709 .owner = THIS_MODULE, 5710 .pf = PF_INET, 5711 .hooknum = NF_INET_POST_ROUTING, 5712 .priority = NF_IP_PRI_SELINUX_LAST, 5713 }, 5714 { 5715 .hook = selinux_ipv4_forward, 5716 .owner = THIS_MODULE, 5717 .pf = PF_INET, 5718 .hooknum = NF_INET_FORWARD, 5719 .priority = NF_IP_PRI_SELINUX_FIRST, 5720 }, 5721 { 5722 .hook = selinux_ipv4_output, 5723 .owner = THIS_MODULE, 5724 .pf = PF_INET, 5725 .hooknum = NF_INET_LOCAL_OUT, 5726 .priority = NF_IP_PRI_SELINUX_FIRST, 5727 } 5728}; 5729 5730#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5731 5732static struct nf_hook_ops selinux_ipv6_ops[] = { 5733 { 5734 .hook = selinux_ipv6_postroute, 5735 .owner = THIS_MODULE, 5736 .pf = PF_INET6, 5737 .hooknum = NF_INET_POST_ROUTING, 5738 .priority = NF_IP6_PRI_SELINUX_LAST, 5739 }, 5740 { 5741 .hook = selinux_ipv6_forward, 5742 .owner = THIS_MODULE, 5743 .pf = PF_INET6, 5744 .hooknum = NF_INET_FORWARD, 5745 .priority = NF_IP6_PRI_SELINUX_FIRST, 5746 } 5747}; 5748 5749#endif /* IPV6 */ 5750 5751static int __init selinux_nf_ip_init(void) 5752{ 5753 int err = 0; 5754 5755 if (!selinux_enabled) 5756 goto out; 5757 5758 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n"); 5759 5760 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5761 if (err) 5762 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err); 5763 5764#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5765 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5766 if (err) 5767 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err); 5768#endif /* IPV6 */ 5769 5770out: 5771 return err; 5772} 5773 5774__initcall(selinux_nf_ip_init); 5775 5776#ifdef CONFIG_SECURITY_SELINUX_DISABLE 5777static void selinux_nf_ip_exit(void) 5778{ 5779 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n"); 5780 5781 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5782#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5783 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5784#endif /* IPV6 */ 5785} 5786#endif 5787 5788#else /* CONFIG_NETFILTER */ 5789 5790#ifdef CONFIG_SECURITY_SELINUX_DISABLE 5791#define selinux_nf_ip_exit() 5792#endif 5793 5794#endif /* CONFIG_NETFILTER */ 5795 5796#ifdef CONFIG_SECURITY_SELINUX_DISABLE 5797static int selinux_disabled; 5798 5799int selinux_disable(void) 5800{ 5801 if (ss_initialized) { 5802 /* Not permitted after initial policy load. */ 5803 return -EINVAL; 5804 } 5805 5806 if (selinux_disabled) { 5807 /* Only do this once. */ 5808 return -EINVAL; 5809 } 5810 5811 printk(KERN_INFO "SELinux: Disabled at runtime.\n"); 5812 5813 selinux_disabled = 1; 5814 selinux_enabled = 0; 5815 5816 reset_security_ops(); 5817 5818 /* Try to destroy the avc node cache */ 5819 avc_disable(); 5820 5821 /* Unregister netfilter hooks. */ 5822 selinux_nf_ip_exit(); 5823 5824 /* Unregister selinuxfs. */ 5825 exit_sel_fs(); 5826 5827 return 0; 5828} 5829#endif 5830