Differential D3043 Diff 7405 lib/libc/secure/__memccpy_chk.c

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lib/libc/secure/__memccpy_chk.c

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				/*-
				* Copyright (C) 2015 Oliver Pinter
				* 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.
				*
				* $FreeBSD$
				*/

				#undef _FORTIFY_SOURCE

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

				void *
				__memccpy_chk(void dest, const void src, int c, size_t n, size_t bos)
				{
				void *ret;
				size_t len;

				if (__predict_false(bos == __FORTIFY_UNKNOWN_SIZE))
				return (memccpy(dest, src, c, n));

				if (__predict_false(n > bos))
				__fortify_chk_fail("memccpy: prevented write past end of buffer");

				/*
				* If n was copied, then return NULL, otherwise
				* a pointer to the byte after the copy of c in the string
				* dest is returned.
				*
				* See the memccpy(3) manpage for more details.
				*/
				pfgUnsubmitted Not Done Inline Actions Missing 's for the first two args ? pfg:* Missing *'s for the first two args ?
				pfgUnsubmitted Not Done Inline Actions These are OK. Nevermind. pfg: These are OK. Nevermind.
				ret = memccpy(dest, src, c, n);
				if (ret != NULL)
				len = ret - dest;

				jillesUnsubmitted Done Inline Actions should have else len = n; jilles: should have ``` else len = n; ```
				if (__predict_false(__fortify_chk_overlap(dest, src, len)))
				__fortify_chk_fail("memccpy: prevented overlapping strings");

				jillesUnsubmitted Done Inline Actions Nothing was prevented, since this code is after the memccpy() call. Therefore, the error message should be adjusted, since it is valid to have an overlap between src..src+n-1 and dest..dest+n-1 if an occurrence of c prevents an actual overlap. jilles: Nothing was prevented, since this code is after the memccpy() call. Therefore, the error…
				return (ret);
				}