Differential D3043 Diff 8100 lib/libc/secure/__fread_chk.c

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lib/libc/secure/__fread_chk.c

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				/*-
				* Copyright (C) 2015 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: fed2659869ec41a93f655be8058568ddab419e01
				*
				* $FreeBSD$
				*/

				#undef _FORTIFY_SOURCE

				#include <sys/cdefs.h>
				#include <secure/security.h>
				#include <stdio.h>
				#include "secure/_stdio.h"

				size_t
				__fread_chk(void __restrict ptr, size_t size, size_t nmemb, FILE __restrict stream, size_t bos)
				{
				size_t total;

				if (__predict_false(bos == __FORTIFY_UNKNOWN_SIZE))
				return (fread(ptr, size, nmemb, stream));

				if (__predict_false(__size_mul_overflow(size, nmemb, &total))) {
				//overflow: trigger the error path in fread
				return (fread(ptr, size, nmemb, stream));
				}
				if (__predict_false(total > bos))
				__fortify_chk_fail("fread: prevented write past end of buffer");

				return (fread(ptr, size, nmemb, stream));
				}