Avoid overflow in memccpy.

Just take the upstream NetBSD code.

Bug: http://code.google.com/p/android/issues/detail?id=43078
Change-Id: Ibbbde9d00e8bc6a09c9503aab2b04b4e3d1f98b0
This commit is contained in:
Elliott Hughes 2013-01-22 14:41:23 -08:00
parent 85597e2b59
commit c51cd764a2
3 changed files with 62 additions and 48 deletions

View file

@ -182,7 +182,6 @@ libc_common_src_files := \
bionic/logd_write.c \
bionic/lseek64.c \
bionic/md5.c \
bionic/memccpy.c \
bionic/memchr.c \
bionic/memmem.c \
bionic/memmove_words.c \
@ -343,6 +342,7 @@ libc_upstream_netbsd_src_files := \
upstream-netbsd/libc/stdlib/tdelete.c \
upstream-netbsd/libc/stdlib/tfind.c \
upstream-netbsd/libc/stdlib/tsearch.c \
upstream-netbsd/libc/string/memccpy.c \
upstream-netbsd/libc/string/strcasestr.c \
upstream-netbsd/libc/string/strxfrm.c \
upstream-netbsd/libc/unistd/killpg.c \

View file

@ -1,47 +0,0 @@
/*
* Copyright (C) 2008 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.
*/
#include <stddef.h>
#include <string.h>
void *memccpy(void *dst, const void *src, int c, size_t n)
{
char* q = dst;
const char* p = src;
const char* p_end = p + n;
char ch = ~(char)c; /* ensure ch != c */
for (;;) {
if (ch == c || p >= p_end) break;
*q++ = ch = *p++;
}
if (p >= p_end && ch != c)
return NULL;
return q;
}

View file

@ -0,0 +1,61 @@
/* $NetBSD: memccpy.c,v 1.13 2012/06/25 22:32:46 abs Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)memccpy.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: memccpy.c,v 1.13 2012/06/25 22:32:46 abs Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include <assert.h>
#include <string.h>
void *
memccpy(void *t, const void *f, int c, size_t n)
{
_DIAGASSERT(t != 0);
_DIAGASSERT(f != 0);
if (n) {
unsigned char *tp = t;
const unsigned char *fp = f;
unsigned char uc = c;
do {
if ((*tp++ = *fp++) == uc)
return (tp);
} while (--n != 0);
}
return (0);
}