FFmpeg
target_dem_fuzzer.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "config.h"
20 #include "libavutil/avassert.h"
21 #include "libavutil/avstring.h"
22 
23 #include "libavcodec/avcodec.h"
24 #include "libavcodec/bytestream.h"
25 #include "libavformat/avformat.h"
26 
27 
28 typedef struct IOContext {
29  int64_t pos;
30  int64_t filesize;
32  int fuzz_size;
33 } IOContext;
34 
35 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
36 
37 static void error(const char *err)
38 {
39  fprintf(stderr, "%s", err);
40  exit(1);
41 }
42 
43 static int io_read(void *opaque, uint8_t *buf, int buf_size)
44 {
45  IOContext *c = opaque;
46  int size = FFMIN(buf_size, c->fuzz_size);
47 
48  if (!c->fuzz_size) {
49  c->filesize = FFMIN(c->pos, c->filesize);
50  return AVERROR_EOF;
51  }
52 
53  memcpy(buf, c->fuzz, size);
54  c->fuzz += size;
55  c->fuzz_size -= size;
56  c->pos += size;
57  c->filesize = FFMAX(c->filesize, c->pos);
58 
59  return size;
60 }
61 
62 static int64_t io_seek(void *opaque, int64_t offset, int whence)
63 {
64  IOContext *c = opaque;
65 
66  if (whence == SEEK_CUR) {
67  if (offset > INT64_MAX - c->pos)
68  return -1;
69  offset += c->pos;
70  } else if (whence == SEEK_END) {
71  if (offset > INT64_MAX - c->filesize)
72  return -1;
73  offset += c->filesize;
74  } else if (whence == AVSEEK_SIZE) {
75  return c->filesize;
76  }
77  if (offset < 0 || offset > c->filesize)
78  return -1;
79  c->pos = offset;
80  return 0;
81 }
82 
83 // Ensure we don't loop forever
84 const uint32_t maxiteration = 8096;
85 
86 static const uint64_t FUZZ_TAG = 0x4741542D5A5A5546ULL;
87 
88 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
89  const uint64_t fuzz_tag = FUZZ_TAG;
90  uint32_t it = 0;
92  AVPacket pkt;
93  char filename[1025] = {0};
94  AVIOContext *fuzzed_pb = NULL;
95  uint8_t *io_buffer;
96  int io_buffer_size = 32768;
97  int64_t filesize = size;
98  IOContext opaque;
99  static int c;
100  int seekable = 0;
101  int ret;
102 
103  if (!c) {
104  av_register_all();
107  c=1;
108  }
109 
110  if (!avfmt)
111  error("Failed avformat_alloc_context()");
112 
113  if (size > 2048) {
114  int flags;
115  char extension[64];
116 
117  GetByteContext gbc;
118  memcpy (filename, data + size - 1024, 1024);
119  bytestream2_init(&gbc, data + size - 2048, 1024);
120  size -= 2048;
121 
122  io_buffer_size = bytestream2_get_le32(&gbc) & 0xFFFFFFF;
123  flags = bytestream2_get_byte(&gbc);
124  seekable = flags & 1;
125  filesize = bytestream2_get_le64(&gbc) & 0x7FFFFFFFFFFFFFFF;
126 
127  if ((flags & 2) && strlen(filename) < sizeof(filename) / 2) {
128  AVInputFormat *avif = NULL;
129  int avif_count = 0;
130  while ((avif = av_iformat_next(avif))) {
131  if (avif->extensions)
132  avif_count ++;
133  }
134  avif_count = bytestream2_get_le32(&gbc) % avif_count;
135 
136  while ((avif = av_iformat_next(avif))) {
137  if (avif->extensions)
138  if (!avif_count--)
139  break;
140  }
141  av_strlcpy(extension, avif->extensions, sizeof(extension));
142  if (strchr(extension, ','))
143  *strchr(extension, ',') = 0;
144  av_strlcatf(filename, sizeof(filename), ".%s", extension);
145  }
146  }
147  io_buffer = av_malloc(io_buffer_size);
148  if (!io_buffer)
149  error("Failed to allocate io_buffer");
150 
151  opaque.filesize = filesize;
152  opaque.pos = 0;
153  opaque.fuzz = data;
154  opaque.fuzz_size= size;
155  fuzzed_pb = avio_alloc_context(io_buffer, io_buffer_size, 0, &opaque,
156  io_read, NULL, seekable ? io_seek : NULL);
157  if (!fuzzed_pb)
158  error("avio_alloc_context failed");
159 
160  avfmt->pb = fuzzed_pb;
161 
162  ret = avformat_open_input(&avfmt, filename, NULL, NULL);
163  if (ret < 0) {
164  av_freep(&fuzzed_pb->buffer);
165  av_freep(&fuzzed_pb);
166  avformat_free_context(avfmt);
167  return 0;
168  }
169 
170  ret = avformat_find_stream_info(avfmt, NULL);
171 
172  av_init_packet(&pkt);
173 
174  //TODO, test seeking
175 
176  for(it = 0; it < maxiteration; it++) {
177  ret = av_read_frame(avfmt, &pkt);
178  if (ret < 0)
179  break;
180  av_packet_unref(&pkt);
181  }
182 end:
183  av_freep(&fuzzed_pb->buffer);
184  av_freep(&fuzzed_pb);
185  avformat_close_input(&avfmt);
186 
187  return 0;
188 }
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
void av_log_set_level(int level)
Set the log level.
Definition: log.c:440
const uint32_t maxiteration
unsigned char * buffer
Start of the buffer.
Definition: avio.h:226
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:533
static AVPacket pkt
static int io_read(void *opaque, uint8_t *buf, int buf_size)
Format I/O context.
Definition: avformat.h:1351
uint8_t
#define av_malloc(s)
#define AV_LOG_PANIC
Something went really wrong and we will crash now.
Definition: log.h:181
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
static const uint64_t FUZZ_TAG
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:208
s EdgeDetect Foobar g libavfilter vf_edgedetect c libavfilter vf_foobar c edit libavfilter and add an entry for foobar following the pattern of the other filters edit libavfilter allfilters and add an entry for foobar following the pattern of the other filters configure make j< whatever > ffmpeg ffmpeg i you should get a foobar png with Lena edge detected That s it
#define AVERROR_EOF
End of file.
Definition: error.h:55
ptrdiff_t size
Definition: opengl_enc.c:100
void avcodec_register_all(void)
Register all the codecs, parsers and bitstream filters which were enabled at configuration time...
Definition: allcodecs.c:882
AVIOContext * avio_alloc_context(unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int(*read_packet)(void *opaque, uint8_t *buf, int buf_size), int(*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t(*seek)(void *opaque, int64_t offset, int whence))
Allocate and initialize an AVIOContext for buffered I/O.
Definition: aviobuf.c:138
simple assert() macros that are a bit more flexible than ISO C assert().
#define FFMAX(a, b)
Definition: common.h:94
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:83
#define FFMIN(a, b)
Definition: common.h:96
int64_t filesize
uint8_t * fuzz
Libavcodec external API header.
AVIOContext * pb
I/O context.
Definition: avformat.h:1393
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:606
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
size_t av_strlcatf(char *dst, size_t size, const char *fmt,...)
Definition: avstring.c:101
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4448
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1773
#define flags(name, subs,...)
Definition: cbs_av1.c:560
const char * extensions
If extensions are defined, then no probe is done.
Definition: avformat.h:671
Main libavformat public API header.
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3615
void av_init_packet(AVPacket *pkt)
Initialize optional fields of a packet with default values.
Definition: avpacket.c:35
#define AVSEEK_SIZE
ORing this as the "whence" parameter to a seek function causes it to return the filesize without seek...
Definition: avio.h:531
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4491
static void error(const char *err)
#define av_freep(p)
This structure stores compressed data.
Definition: packet.h:340
static int64_t io_seek(void *opaque, int64_t offset, int whence)