| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* $OpenBSD: reallocarray.c,v 1.1 2014/05/08 21:43:49 deraadt 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. |
| */ |
| |
| #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; |
| } |
| /* |
| * Head off variations in realloc behavior on different |
| * platforms (reported by MarkR <mrogers6@users.sf.net>) |
| * |
| * The behaviour of reallocarray is implementation-defined if |
| * nmemb or size is zero. It can return NULL or non-NULL |
| * depending on the platform. |
| * https://www.securecoding.cert.org/confluence/display/c/MEM04-C.Beware+of+zero-lengthallocations |
| * |
| * Here are some extracts from realloc man pages on different platforms. |
| * |
| * void realloc( void memblock, size_t size ); |
| * |
| * Windows: |
| * |
| * If there is not enough available memory to expand the block |
| * to the given size, the original block is left unchanged, |
| * and NULL is returned. If size is zero, then the block |
| * pointed to by memblock is freed; the return value is NULL, |
| * and memblock is left pointing at a freed block. |
| * |
| * OpenBSD: |
| * |
| * If size or nmemb is equal to 0, a unique pointer to an |
| * access protected, zero sized object is returned. Access via |
| * this pointer will generate a SIGSEGV exception. |
| * |
| * Linux: |
| * |
| * If size was equal to 0, either NULL or a pointer suitable |
| * to be passed to free() is returned. |
| * |
| * OS X: |
| * |
| * If size is zero and ptr is not NULL, a new, minimum sized |
| * object is allocated and the original object is freed. |
| * |
| * It looks like images with zero width or height can trigger |
| * this, and fuzzing behaviour will differ by platform, so |
| * fuzzing on one platform may not detect zero-size allocation |
| * problems on other platforms. |
| */ |
| if (size == 0 || nmemb == 0) |
| return NULL; |
| return realloc(optr, size * nmemb); |
| } |