Differential D3459 Diff 8407 lib/libc/secure/__strlen_chk.c

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lib/libc/secure/__strlen_chk.c

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				/*-
				* Copyright (C) 2012 The Android Open Source Project
				* All rights reserved.
				*
				* Redistribution and use in source and binary forms, with or without
				* modification, are permitted provided that the following conditions
				* are met:
				* * Redistributions of source code must retain the above copyright
				* notice, this list of conditions and the following disclaimer.
				* * Redistributions in binary form must reproduce the above copyright
				* notice, this list of conditions and the following disclaimer in
				* the documentation and/or other materials provided with the
				* distribution.
				*
				* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
				* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
				* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
				* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
				* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
				* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
				* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
				* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
				* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
				* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
				* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
				* SUCH DAMAGE.
				*
				* bionic rev: d807b9a12d3e49132b095df3d883618452033b51
				*
				* $FreeBSD$
				*/

				#undef _FORTIFY_SOURCE

				#include <sys/cdefs.h>
				#include <secure/security.h>
				#include <string.h>
				#include <stdlib.h>
				#include "secure/_string.h"

				/*
				* 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.
				*/
				size_t
				__strlen_chk(const char *s, size_t bos)
				{
				size_t ret;

				if (__predict_false(bos == __FORTIFY_UNKNOWN_SIZE))
				return (strlen(s));

				ret = strlen(s);
				if (__predict_false(ret >= bos))
				__fortify_chk_fail("strlen: detected read past end of buffer");

				return (ret);
				}