This test is designed to detect code such as:
int main() {
  char buf[10];
  memcpy(buf, "1234567890", sizeof(buf));
  size_t len = strlen(buf); // segfault here with _FORTIFY_SOURCE
  printf("%d\n", len);
  return 0;
}
or anytime strlen reads beyond an object boundary. This should
help address memory leakage vulnerabilities and make other
unrelated vulnerabilities harder to exploit.
Change-Id: I354b425be7bef4713c85f6bab0e9738445e00182
		
	
		
			
				
	
	
		
			68 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2012 The Android Open Source Project
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *  * Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 *  * Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in
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 *    the documentation and/or other materials provided with the
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 *    distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#include <string.h>
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#include <stdlib.h>
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#include <private/logd.h>
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/*
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 * Runtime implementation of __strlen_chk.
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 *
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 * See
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 *   http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
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 *   http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
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 * for details.
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 *
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 * This strlen check is called if _FORTIFY_SOURCE is defined and
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 * greater than 0.
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 *
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 * This test is designed to detect code such as:
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 *
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 * int main() {
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 *   char buf[10];
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 *   memcpy(buf, "1234567890", sizeof(buf));
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 *   size_t len = strlen(buf); // segfault here with _FORTIFY_SOURCE
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 *   printf("%d\n", len);
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 *   return 0;
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 * }
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 *
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 * or anytime strlen reads beyond an object boundary.
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 */
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size_t __strlen_chk(const char *s, size_t s_len)
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{
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    size_t ret = strlen(s);
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    if (__builtin_expect(ret >= s_len, 0)) {
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        __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
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            "*** strlen read overflow detected ***\n");
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        abort();
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    }
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    return ret;
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}
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