1 /* alloc - Convenience routines for safely allocating memory
2 * Copyright (C) 2007 Josh Coalson
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #ifndef FLAC__SHARE__ALLOC_H
20 #define FLAC__SHARE__ALLOC_H
21
22 #ifdef HAVE_CONFIG_H
23 # include <config.h>
24 #endif
25
26 /* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
27 * before #including this file, otherwise SIZE_MAX might not be defined
28 */
29
30 #include <limits.h> /* for SIZE_MAX */
31 #if !defined _MSC_VER && !defined __MINGW32__ && !defined __EMX__
32 #include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
33 #endif
34 #include <stdlib.h> /* for size_t, malloc(), etc */
35
36 #ifndef SIZE_MAX
37 # ifndef SIZE_T_MAX
38 # ifdef _MSC_VER
39 # define SIZE_T_MAX UINT_MAX
40 # else
41 # error
42 # endif
43 # endif
44 # define SIZE_MAX SIZE_T_MAX
45 #endif
46
47 #ifndef FLaC__INLINE
48 #define FLaC__INLINE
49 #endif
50
51 /* avoid malloc()ing 0 bytes, see:
52 * https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
53 */
safe_malloc_(size_t size)54 static FLaC__INLINE void *safe_malloc_(size_t size)
55 {
56 /* malloc(0) is undefined; FLAC src convention is to always allocate */
57 if(!size)
58 size++;
59 return malloc(size);
60 }
61
safe_calloc_(size_t nmemb,size_t size)62 static FLaC__INLINE void *safe_calloc_(size_t nmemb, size_t size)
63 {
64 if(!nmemb || !size)
65 return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
66 return calloc(nmemb, size);
67 }
68
69 /*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
70
safe_malloc_add_2op_(size_t size1,size_t size2)71 static FLaC__INLINE void *safe_malloc_add_2op_(size_t size1, size_t size2)
72 {
73 size2 += size1;
74 if(size2 < size1)
75 return 0;
76 return safe_malloc_(size2);
77 }
78
safe_malloc_add_3op_(size_t size1,size_t size2,size_t size3)79 static FLaC__INLINE void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
80 {
81 size2 += size1;
82 if(size2 < size1)
83 return 0;
84 size3 += size2;
85 if(size3 < size2)
86 return 0;
87 return safe_malloc_(size3);
88 }
89
safe_malloc_add_4op_(size_t size1,size_t size2,size_t size3,size_t size4)90 static FLaC__INLINE void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
91 {
92 size2 += size1;
93 if(size2 < size1)
94 return 0;
95 size3 += size2;
96 if(size3 < size2)
97 return 0;
98 size4 += size3;
99 if(size4 < size3)
100 return 0;
101 return safe_malloc_(size4);
102 }
103
safe_malloc_mul_2op_(size_t size1,size_t size2)104 static FLaC__INLINE void *safe_malloc_mul_2op_(size_t size1, size_t size2)
105 #if 0
106 needs support for cases where sizeof(size_t) != 4
107 {
108 /* could be faster #ifdef'ing off SIZEOF_SIZE_T */
109 if(sizeof(size_t) == 4) {
110 if ((double)size1 * (double)size2 < 4294967296.0)
111 return malloc(size1*size2);
112 }
113 return 0;
114 }
115 #else
116 /* better? */
117 {
118 if(!size1 || !size2)
119 return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
120 if(size1 > SIZE_MAX / size2)
121 return 0;
122 return malloc(size1*size2);
123 }
124 #endif
125
safe_malloc_mul_3op_(size_t size1,size_t size2,size_t size3)126 static FLaC__INLINE void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
127 {
128 if(!size1 || !size2 || !size3)
129 return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
130 if(size1 > SIZE_MAX / size2)
131 return 0;
132 size1 *= size2;
133 if(size1 > SIZE_MAX / size3)
134 return 0;
135 return malloc(size1*size3);
136 }
137
138 /* size1*size2 + size3 */
safe_malloc_mul2add_(size_t size1,size_t size2,size_t size3)139 static FLaC__INLINE void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
140 {
141 if(!size1 || !size2)
142 return safe_malloc_(size3);
143 if(size1 > SIZE_MAX / size2)
144 return 0;
145 return safe_malloc_add_2op_(size1*size2, size3);
146 }
147
148 /* size1 * (size2 + size3) */
safe_malloc_muladd2_(size_t size1,size_t size2,size_t size3)149 static FLaC__INLINE void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3)
150 {
151 if(!size1 || (!size2 && !size3))
152 return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
153 size2 += size3;
154 if(size2 < size3)
155 return 0;
156 return safe_malloc_mul_2op_(size1, size2);
157 }
158
safe_realloc_add_2op_(void * ptr,size_t size1,size_t size2)159 static FLaC__INLINE void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
160 {
161 size2 += size1;
162 if(size2 < size1)
163 return 0;
164 return realloc(ptr, size2);
165 }
166
safe_realloc_add_3op_(void * ptr,size_t size1,size_t size2,size_t size3)167 static FLaC__INLINE void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
168 {
169 size2 += size1;
170 if(size2 < size1)
171 return 0;
172 size3 += size2;
173 if(size3 < size2)
174 return 0;
175 return realloc(ptr, size3);
176 }
177
safe_realloc_add_4op_(void * ptr,size_t size1,size_t size2,size_t size3,size_t size4)178 static FLaC__INLINE void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
179 {
180 size2 += size1;
181 if(size2 < size1)
182 return 0;
183 size3 += size2;
184 if(size3 < size2)
185 return 0;
186 size4 += size3;
187 if(size4 < size3)
188 return 0;
189 return realloc(ptr, size4);
190 }
191
safe_realloc_mul_2op_(void * ptr,size_t size1,size_t size2)192 static FLaC__INLINE void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
193 {
194 if(!size1 || !size2)
195 return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
196 if(size1 > SIZE_MAX / size2)
197 return 0;
198 return realloc(ptr, size1*size2);
199 }
200
201 /* size1 * (size2 + size3) */
safe_realloc_muladd2_(void * ptr,size_t size1,size_t size2,size_t size3)202 static FLaC__INLINE void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
203 {
204 if(!size1 || (!size2 && !size3))
205 return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
206 size2 += size3;
207 if(size2 < size3)
208 return 0;
209 return safe_realloc_mul_2op_(ptr, size1, size2);
210 }
211
212 #endif
213