/* alloc - Convenience routines for safely allocating memory
* Copyright (C) 2007-2009 Josh Coalson
* Copyright (C) 2011-2025 Xiph.Org Foundation
*
* 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.
*
* - Neither the name of the Xiph.org Foundation 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 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 FOUNDATION 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.
*/
#ifndef FLAC__SHARE__ALLOC_H
#define FLAC__SHARE__ALLOC_H
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
/* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
* before #including this file, otherwise SIZE_MAX might not be defined
*/
#include <limits.h> /* for SIZE_MAX */
#ifdef HAVE_STDINT_H
#include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
#endif
#include <stdlib.h> /* for size_t, malloc(), etc */
#include "share/compat.h"
#ifndef SIZE_MAX
# ifndef SIZE_T_MAX
# ifdef _MSC_VER
# ifdef _WIN64
# define SIZE_T_MAX FLAC__U64L(0xffffffffffffffff)
# else
# define SIZE_T_MAX 0xffffffff
# endif
# else
# error
# endif
# endif
# define SIZE_MAX SIZE_T_MAX
#endif
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
extern int alloc_check_threshold, alloc_check_counter, alloc_check_keep_failing;
static inline int alloc_check(void) {
if(alloc_check_threshold == INT32_MAX)
return 0;
else if(alloc_check_counter++ == alloc_check_threshold)
return 1;
else if(alloc_check_keep_failing && (alloc_check_counter > alloc_check_threshold))
return 1;
else {
return 0;
}
}
#endif
/* avoid malloc()ing 0 bytes, see:
* https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
*/
static inline void *safe_malloc_(size_t size)
{
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
/* Fail if requested */
if(alloc_check())
return NULL;
#endif
/* malloc(0) is undefined; FLAC src convention is to always allocate */
if(!size)
size++;
return malloc(size);
}
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
static inline void *malloc_(size_t size)
{
/* Fail if requested */
if(alloc_check())
return NULL;
return malloc(size);
}
#else
#define malloc_ malloc
#endif
static inline void *safe_calloc_(size_t nmemb, size_t size)
{
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
/* Fail if requested */
if(alloc_check())
return NULL;
#endif
if(!nmemb || !size)
return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
return calloc(nmemb, size);
}
/*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
static inline void *safe_malloc_add_2op_(size_t size1, size_t size2)
{
size2 += size1;
if(size2 < size1)
return 0;
return safe_malloc_(size2);
}
static inline void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
return safe_malloc_(size3);
}
static inline void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
size4 += size3;
if(size4 < size3)
return 0;
return safe_malloc_(size4);
}
void *safe_malloc_mul_2op_(size_t size1, size_t size2) ;
static inline void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
{
if(!size1 || !size2 || !size3)
return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
if(size1 > SIZE_MAX / size2)
return 0;
size1 *= size2;
if(size1 > SIZE_MAX / size3)
return 0;
return malloc_(size1*size3);
}
/* size1*size2 + size3 */
static inline void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
{
if(!size1 || !size2)
return safe_malloc_(size3);
if(size1 > SIZE_MAX / size2)
return 0;
return safe_malloc_add_2op_(size1*size2, size3);
}
/* size1 * (size2 + size3) */
static inline void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3)
{
if(!size1 || (!size2 && !size3))
return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
size2 += size3;
if(size2 < size3)
return 0;
if(size1 > SIZE_MAX / size2)
return 0;
return malloc_(size1*size2);
}
static inline void *safe_realloc_(void *ptr, size_t size)
{
void *oldptr;
void *newptr;
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
/* Fail if requested */
if(alloc_check() && size > 0) {
free(ptr);
return NULL;
}
#endif
oldptr = ptr;
newptr = realloc(ptr, size);
if(size > 0 && newptr == 0)
free(oldptr);
return newptr;
}
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
static inline void *realloc_(void *ptr, size_t size)
{
/* Fail if requested */
if(alloc_check())
return NULL;
return realloc(ptr, size);
}
#else
#define realloc_ realloc
#endif
static inline void *safe_realloc_nofree_add_2op_(void *ptr, size_t size1, size_t size2)
{
size2 += size1;
if(size2 < size1)
return 0;
return realloc_(ptr, size2);
}
static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
{
size2 += size1;
if(size2 < size1) {
free(ptr);
return 0;
}
size3 += size2;
if(size3 < size2) {
free(ptr);
return 0;
}
return safe_realloc_(ptr, size3);
}
static inline void *safe_realloc_nofree_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
return realloc_(ptr, size3);
}
static inline void *safe_realloc_nofree_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
{
size2 += size1;
if(size2 < size1)
return 0;
size3 += size2;
if(size3 < size2)
return 0;
size4 += size3;
if(size4 < size3)
return 0;
return realloc_(ptr, size4);
}
static inline void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
{
if(!size1 || !size2)
return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
if(size1 > SIZE_MAX / size2) {
free(ptr);
return 0;
}
return safe_realloc_(ptr, size1*size2);
}
static inline void *safe_realloc_nofree_mul_2op_(void *ptr, size_t size1, size_t size2)
{
if(!size1 || !size2)
return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
if(size1 > SIZE_MAX / size2)
return 0;
return realloc_(ptr, size1*size2);
}
/* size1 * (size2 + size3) */
static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
{
if(!size1 || (!size2 && !size3))
return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
size2 += size3;
if(size2 < size3) {
free(ptr);
return 0;
}
return safe_realloc_mul_2op_(ptr, size1, size2);
}
/* size1 * (size2 + size3) */
static inline void *safe_realloc_nofree_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
{
if(!size1 || (!size2 && !size3))
return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
size2 += size3;
if(size2 < size3)
return 0;
return safe_realloc_nofree_mul_2op_(ptr, size1, size2);
}
#endif