1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <inttypes.h>
18#include <limits.h>
19#include <stdio.h>
20#include <sys/capability.h>
21#include <sys/mman.h>
22#include <sys/prctl.h>
23#include <unistd.h>
24
25#include <string>
26#include <vector>
27
28#include <gtest/gtest.h>
29
30#include "android-base/file.h"
31#include "android-base/strings.h"
32#include "private/bionic_prctl.h"
33
34// http://b/20017123.
35TEST(sys_prctl, bug_20017123) {
36#if defined(__ANDROID__) // PR_SET_VMA is only available in Android kernels.
37  size_t page_size = static_cast<size_t>(sysconf(_SC_PAGESIZE));
38  void* p = mmap(NULL, page_size * 3, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
39  ASSERT_NE(MAP_FAILED, p);
40  ASSERT_EQ(0, mprotect(p, page_size, PROT_NONE));
41  ASSERT_NE(-1, prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, p, page_size * 3, "anonymous map space"));
42  // Now read the maps and verify that there are no overlapped maps.
43  std::string file_data;
44  ASSERT_TRUE(android::base::ReadFileToString("/proc/self/maps", &file_data));
45
46  uintptr_t last_end = 0;
47  std::vector<std::string> lines = android::base::Split(file_data, "\n");
48  for (size_t i = 0; i < lines.size(); i++) {
49    if (lines[i].empty()) {
50      continue;
51    }
52    uintptr_t start;
53    uintptr_t end;
54    ASSERT_EQ(2, sscanf(lines[i].c_str(), "%" SCNxPTR "-%" SCNxPTR " ", &start, &end))
55        << "Failed to parse line: " << lines[i];
56    // This will never fail on the first line, so no need to do any special checking.
57    ASSERT_GE(start, last_end)
58        << "Overlapping map detected:\n" << lines[i -1] << '\n' << lines[i] << '\n';
59    last_end = end;
60  }
61
62  ASSERT_EQ(0, munmap(p, page_size * 3));
63#else
64  GTEST_LOG_(INFO) << "This test does nothing as it tests an Android specific kernel feature.";
65#endif
66}
67
68TEST(sys_prctl, pr_cap_ambient) {
69// PR_CAP_AMBIENT was introduced in v4.3.  Android devices should always
70// have a backport, but we can't guarantee it's available on the host.
71#if defined(__ANDROID__) || defined(PR_CAP_AMBIENT)
72  const std::string caps_sha =
73      "https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/"
74      "?id=58319057b7847667f0c9585b9de0e8932b0fdb08";
75  const std::string caps_typo_sha =
76      "https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/"
77      "?id=b7f76ea2ef6739ee484a165ffbac98deb855d3d3";
78
79  auto err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0);
80  EXPECT_EQ(0, err);
81  // EINVAL -> unrecognized prctl option
82  ASSERT_NE(EINVAL, errno) << "kernel missing required commits:\n"
83                           << caps_sha << "\n"
84                           << caps_typo_sha << "\n";
85
86  // Unprivileged processes shouldn't be able to raise CAP_SYS_ADMIN,
87  // but they can check or lower it
88  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_SYS_ADMIN, 0, 0);
89  EXPECT_EQ(-1, err);
90  EXPECT_EQ(EPERM, errno);
91
92  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_SYS_ADMIN, 0, 0);
93  EXPECT_EQ(0, err);
94
95  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_LOWER, CAP_SYS_ADMIN, 0, 0);
96  EXPECT_EQ(0, err);
97
98  // ULONG_MAX isn't a legal cap
99  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, ULONG_MAX, 0, 0);
100  EXPECT_EQ(-1, err);
101  EXPECT_EQ(EINVAL, errno);
102
103  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, ULONG_MAX, 0, 0);
104  EXPECT_EQ(-1, err);
105  EXPECT_EQ(EINVAL, errno);
106
107  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_LOWER, ULONG_MAX, 0, 0);
108  EXPECT_EQ(-1, err);
109  EXPECT_EQ(EINVAL, errno);
110#else
111  GTEST_LOG_(INFO)
112      << "Skipping test that requires host support for PR_CAP_AMBIENT.";
113#endif
114}
115