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1 /*
2 # Copyright 2018 Google Inc.
3 #
4 # Licensed under the Apache License, Version 2.0 (the "License");
5 # you may not use this file except in compliance with the License.
6 # You may obtain a copy of the License at
7 #
8 #      http://www.apache.org/licenses/LICENSE-2.0
9 #
10 # Unless required by applicable law or agreed to in writing, software
11 # distributed under the License is distributed on an "AS IS" BASIS,
12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 # See the License for the specific language governing permissions and
14 # limitations under the License.
15 #
16 ################################################################################
17 */
18 
19 #include <cstdint>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <stdio.h>
23 
24 #include "jbig2.h"
25 
26 #define ALIGNMENT ((size_t) 16)
27 #define KBYTE ((size_t) 1024)
28 #define MBYTE (1024 * KBYTE)
29 #define GBYTE (1024 * MBYTE)
30 #define MAX_ALLOCATION (1 * GBYTE)
31 
32 static size_t used;
33 
jbig2_fuzzer_reached_limit(size_t oldsize,size_t size)34 static void *jbig2_fuzzer_reached_limit(size_t oldsize, size_t size)
35 {
36   if (oldsize == 0)
37     fprintf(stderr, "limit: %zu Mbyte used: %zu Mbyte allocation: %zu: limit reached\n", MAX_ALLOCATION / MBYTE, used / MBYTE, size);
38   else
39     fprintf(stderr, "limit: %zu Mbyte used: %zu Mbyte reallocation: %zu -> %zu: limit reached\n", MAX_ALLOCATION / MBYTE, used / MBYTE, oldsize, size);
40   fflush(0);
41   return NULL;
42 }
43 
jbig2_fuzzer_alloc(Jbig2Allocator * allocator,size_t size)44 static void *jbig2_fuzzer_alloc(Jbig2Allocator *allocator, size_t size)
45 {
46   char *ptr = NULL;
47 
48   if (size == 0)
49     return NULL;
50   if (size > SIZE_MAX - ALIGNMENT)
51     return NULL;
52   if (size + ALIGNMENT > MAX_ALLOCATION - used)
53     return jbig2_fuzzer_reached_limit(0, size + ALIGNMENT);
54 
55   ptr = (char *) malloc(size + ALIGNMENT);
56   if (ptr == NULL)
57     return NULL;
58 
59   memcpy(ptr, &size, sizeof(size));
60   used += size + ALIGNMENT;
61 
62   return ptr + ALIGNMENT;
63 }
64 
jbig2_fuzzer_free(Jbig2Allocator * allocator,void * ptr)65 static void jbig2_fuzzer_free(Jbig2Allocator *allocator, void *ptr)
66 {
67   size_t size;
68 
69   if (ptr == NULL)
70     return;
71   if (ptr < (void *) ALIGNMENT)
72     return;
73 
74   ptr = (char *) ptr - ALIGNMENT;
75   memcpy(&size, ptr, sizeof(size));
76 
77   used -= size + ALIGNMENT;
78   free(ptr);
79 }
80 
jbig2_fuzzer_realloc(Jbig2Allocator * allocator,void * old,size_t size)81 static void *jbig2_fuzzer_realloc(Jbig2Allocator *allocator, void *old, size_t size)
82 {
83   size_t oldsize;
84   char *ptr;
85 
86   if (old == NULL)
87     return jbig2_fuzzer_alloc(allocator, size);
88   if (old < (void *) ALIGNMENT)
89     return NULL;
90 
91   if (size == 0) {
92     jbig2_fuzzer_free(allocator, old);
93     return NULL;
94   }
95   if (size > SIZE_MAX - ALIGNMENT)
96     return NULL;
97 
98   old = (char *) old - ALIGNMENT;
99   memcpy(&oldsize, old, sizeof(oldsize));
100 
101   if (size + ALIGNMENT > MAX_ALLOCATION - used + oldsize + ALIGNMENT)
102     return jbig2_fuzzer_reached_limit(oldsize + ALIGNMENT, size + ALIGNMENT);
103 
104   ptr = (char *) realloc(old, size + ALIGNMENT);
105   if (ptr == NULL)
106     return NULL;
107 
108   used -= oldsize + ALIGNMENT;
109   memcpy(ptr, &size, sizeof(size));
110   used += size + ALIGNMENT;
111 
112   return ptr + ALIGNMENT;
113 }
114 
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)115 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
116   Jbig2Allocator allocator;
117   Jbig2Ctx *ctx = NULL;
118 
119   used = 0;
120 
121   allocator.alloc = jbig2_fuzzer_alloc;
122   allocator.free = jbig2_fuzzer_free;
123   allocator.realloc = jbig2_fuzzer_realloc;
124 
125   ctx = jbig2_ctx_new(&allocator, (Jbig2Options) 0, NULL, NULL, NULL);
126   if (jbig2_data_in(ctx, data, size) == 0)
127   {
128     if (jbig2_complete_page(ctx) == 0)
129     {
130       Jbig2Image *image = jbig2_page_out(ctx);
131       if (image != NULL)
132       {
133         int sum = 0;
134         for (int i = 0; i < image->height * image->stride; i++)
135           sum += image->data[i];
136         printf("sum of image data bytes: %d\n", sum);
137       }
138       jbig2_release_page(ctx, image);
139     }
140   }
141   jbig2_ctx_free(ctx);
142 
143   return 0;
144 }
145