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      1 /* alloc - Convenience routines for safely allocating memory
      2  * Copyright (C) 2007-2009  Josh Coalson
      3  * Copyright (C) 2011-2014  Xiph.Org Foundation
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *
      9  * - Redistributions of source code must retain the above copyright
     10  * notice, this list of conditions and the following disclaimer.
     11  *
     12  * - Redistributions in binary form must reproduce the above copyright
     13  * notice, this list of conditions and the following disclaimer in the
     14  * documentation and/or other materials provided with the distribution.
     15  *
     16  * - Neither the name of the Xiph.org Foundation nor the names of its
     17  * contributors may be used to endorse or promote products derived from
     18  * this software without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
     24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifndef FLAC__SHARE__ALLOC_H
     34 #define FLAC__SHARE__ALLOC_H
     35 
     36 #ifdef HAVE_CONFIG_H
     37 #  include <config.h>
     38 #endif
     39 
     40 /* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
     41  * before #including this file,  otherwise SIZE_MAX might not be defined
     42  */
     43 
     44 #include <limits.h> /* for SIZE_MAX */
     45 #if HAVE_STDINT_H
     46 #include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
     47 #endif
     48 #include <stdlib.h> /* for size_t, malloc(), etc */
     49 #include "share/compat.h"
     50 
     51 #ifndef SIZE_MAX
     52 # ifndef SIZE_T_MAX
     53 #  ifdef _MSC_VER
     54 #   ifdef _WIN64
     55 #    define SIZE_T_MAX 0xffffffffffffffffui64
     56 #   else
     57 #    define SIZE_T_MAX 0xffffffff
     58 #   endif
     59 #  else
     60 #   error
     61 #  endif
     62 # endif
     63 # define SIZE_MAX SIZE_T_MAX
     64 #endif
     65 
     66 /* avoid malloc()ing 0 bytes, see:
     67  * https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
     68 */
     69 static inline void *safe_malloc_(size_t size)
     70 {
     71 	/* malloc(0) is undefined; FLAC src convention is to always allocate */
     72 	if(!size)
     73 		size++;
     74 	return malloc(size);
     75 }
     76 
     77 static inline void *safe_calloc_(size_t nmemb, size_t size)
     78 {
     79 	if(!nmemb || !size)
     80 		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
     81 	return calloc(nmemb, size);
     82 }
     83 
     84 /*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
     85 
     86 static inline void *safe_malloc_add_2op_(size_t size1, size_t size2)
     87 {
     88 	size2 += size1;
     89 	if(size2 < size1)
     90 		return 0;
     91 	return safe_malloc_(size2);
     92 }
     93 
     94 static inline void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
     95 {
     96 	size2 += size1;
     97 	if(size2 < size1)
     98 		return 0;
     99 	size3 += size2;
    100 	if(size3 < size2)
    101 		return 0;
    102 	return safe_malloc_(size3);
    103 }
    104 
    105 static inline void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
    106 {
    107 	size2 += size1;
    108 	if(size2 < size1)
    109 		return 0;
    110 	size3 += size2;
    111 	if(size3 < size2)
    112 		return 0;
    113 	size4 += size3;
    114 	if(size4 < size3)
    115 		return 0;
    116 	return safe_malloc_(size4);
    117 }
    118 
    119 void *safe_malloc_mul_2op_(size_t size1, size_t size2) ;
    120 
    121 static inline void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
    122 {
    123 	if(!size1 || !size2 || !size3)
    124 		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
    125 	if(size1 > SIZE_MAX / size2)
    126 		return 0;
    127 	size1 *= size2;
    128 	if(size1 > SIZE_MAX / size3)
    129 		return 0;
    130 	return malloc(size1*size3);
    131 }
    132 
    133 /* size1*size2 + size3 */
    134 static inline void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
    135 {
    136 	if(!size1 || !size2)
    137 		return safe_malloc_(size3);
    138 	if(size1 > SIZE_MAX / size2)
    139 		return 0;
    140 	return safe_malloc_add_2op_(size1*size2, size3);
    141 }
    142 
    143 /* size1 * (size2 + size3) */
    144 static inline void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3)
    145 {
    146 	if(!size1 || (!size2 && !size3))
    147 		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
    148 	size2 += size3;
    149 	if(size2 < size3)
    150 		return 0;
    151 	if(size1 > SIZE_MAX / size2)
    152 		return 0;
    153 	return malloc(size1*size2);
    154 }
    155 
    156 static inline void *safe_realloc_(void *ptr, size_t size)
    157 {
    158 	void *oldptr = ptr;
    159 	void *newptr = realloc(ptr, size);
    160 	if(size > 0 && newptr == 0)
    161 		free(oldptr);
    162 	return newptr;
    163 }
    164 static inline void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
    165 {
    166 	size2 += size1;
    167 	if(size2 < size1) {
    168 		free(ptr);
    169 		return 0;
    170 	}
    171 	return realloc(ptr, size2);
    172 }
    173 
    174 static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
    175 {
    176 	size2 += size1;
    177 	if(size2 < size1)
    178 		return 0;
    179 	size3 += size2;
    180 	if(size3 < size2)
    181 		return 0;
    182 	return realloc(ptr, size3);
    183 }
    184 
    185 static inline void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
    186 {
    187 	size2 += size1;
    188 	if(size2 < size1)
    189 		return 0;
    190 	size3 += size2;
    191 	if(size3 < size2)
    192 		return 0;
    193 	size4 += size3;
    194 	if(size4 < size3)
    195 		return 0;
    196 	return realloc(ptr, size4);
    197 }
    198 
    199 static inline void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
    200 {
    201 	if(!size1 || !size2)
    202 		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
    203 	if(size1 > SIZE_MAX / size2)
    204 		return 0;
    205 	return safe_realloc_(ptr, size1*size2);
    206 }
    207 
    208 /* size1 * (size2 + size3) */
    209 static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
    210 {
    211 	if(!size1 || (!size2 && !size3))
    212 		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
    213 	size2 += size3;
    214 	if(size2 < size3)
    215 		return 0;
    216 	return safe_realloc_mul_2op_(ptr, size1, size2);
    217 }
    218 
    219 #endif
    220