openssh/openbsd-compat/reallocarray.c
Damien Miller 7de5991aa3 upstream libc change
revision 1.2
date: 2014/12/08 03:45:00;  author: bcook;  state: Exp;  lines: +2 -2;  commitid: 7zWEBgJJOCZ2hvTV;
avoid left shift overflow in reallocarray.

Some 64-bit platforms (e.g. Windows 64) have a 32-bit long. So, shifting
1UL 32-bits to the left causes an overflow. This replaces the constant 1UL with
(size_t)1 so that we get the correct constant size for the platform.

discussed with tedu@ & deraadt@
2014-12-18 11:44:06 +11:00

45 lines
1.5 KiB
C

/* $OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $ */
/*
* Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* OPENBSD ORIGINAL: lib/libc/stdlib/reallocarray.c */
#include "includes.h"
#ifndef HAVE_REALLOCARRAY
#include <sys/types.h>
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
/*
* This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
* if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
*/
#define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
void *
reallocarray(void *optr, size_t nmemb, size_t size)
{
if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
nmemb > 0 && SIZE_MAX / nmemb < size) {
errno = ENOMEM;
return NULL;
}
return realloc(optr, size * nmemb);
}
#endif /* HAVE_REALLOCARRAY */