__readlink_chk.cpp revision 42281880a8ac8614832ff918a14e4b950f35d05d
142281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay/* 242281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * Copyright (C) 2015 The Android Open Source Project 342281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * All rights reserved. 442281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * 542281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * Redistribution and use in source and binary forms, with or without 642281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * modification, are permitted provided that the following conditions 742281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * are met: 842281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * * Redistributions of source code must retain the above copyright 942281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * notice, this list of conditions and the following disclaimer. 1042281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * * Redistributions in binary form must reproduce the above copyright 1142281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * notice, this list of conditions and the following disclaimer in 1242281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * the documentation and/or other materials provided with the 1342281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * distribution. 1442281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * 1542281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 1642281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 1742281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 1842281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 1942281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 2042281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 2142281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 2242281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 2342281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 2442281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 2542281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2642281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay * SUCH DAMAGE. 2742281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay */ 2842281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay 2942281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay#undef _FORTIFY_SOURCE 3042281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay#include <unistd.h> 3142281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay#include "private/libc_logging.h" 3242281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay 3342281880a8ac8614832ff918a14e4b950f35d05dDaniel Micayextern "C" ssize_t __readlink_chk(const char* path, char* buf, size_t size, size_t buf_size) { 3442281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay if (__predict_false(size > buf_size)) { 3542281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay __fortify_chk_fail("readlink: prevented write past end of buffer", 0); 3642281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay } 3742281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay 3842281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay if (__predict_false(size > SSIZE_MAX)) { 3942281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay __fortify_chk_fail("readlink: size > SSIZE_MAX", 0); 4042281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay } 4142281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay 4242281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay return readlink(path, buf, size); 4342281880a8ac8614832ff918a14e4b950f35d05dDaniel Micay} 44