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 /* Targeted fuzzer that targets specific codecs depending on two
20 compile-time flags.
21 INSTRUCTIONS:
22
23 * Get the very fresh clang, e.g. see http://libfuzzer.info#versions
24 * Get and build libFuzzer:
25 svn co http://llvm.org/svn/llvm-project/llvm/trunk/lib/Fuzzer
26 ./Fuzzer/build.sh
27 * build ffmpeg for fuzzing:
28 FLAGS="-fsanitize=address -fsanitize-coverage=trace-pc-guard,trace-cmp -g" CC="clang $FLAGS" CXX="clang++ $FLAGS" ./configure --disable-x86asm
29 make clean && make -j
30 * build the fuzz target.
31 Choose the value of FFMPEG_CODEC (e.g. AV_CODEC_ID_DVD_SUBTITLE) and
32 choose one of FUZZ_FFMPEG_VIDEO, FUZZ_FFMPEG_AUDIO, FUZZ_FFMPEG_SUBTITLE.
33 clang -fsanitize=address -fsanitize-coverage=trace-pc-guard,trace-cmp tools/target_dec_fuzzer.c -o target_dec_fuzzer -I. -DFFMPEG_CODEC=AV_CODEC_ID_MPEG1VIDEO -DFUZZ_FFMPEG_VIDEO ../../libfuzzer/libFuzzer.a -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Llibpostproc -Llibswscale -Llibswresample -Wl,--as-needed -Wl,-z,noexecstack -Wl,--warn-common -Wl,-rpath-link=:libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample -lavdevice -lavfilter -lavformat -lavcodec -lswresample -lswscale -lavutil -ldl -lxcb -lxcb-shm -lxcb -lxcb-xfixes -lxcb -lxcb-shape -lxcb -lX11 -lasound -lm -lbz2 -lz -pthread
34 * create a corpus directory and put some samples there (empty dir is ok too):
35 mkdir CORPUS && cp some-files CORPUS
36
37 * Run fuzzing:
38 ./target_dec_fuzzer -max_len=100000 CORPUS
39
40 More info:
41 http://libfuzzer.info
42 http://tutorial.libfuzzer.info
43 https://github.com/google/oss-fuzz
44 http://lcamtuf.coredump.cx/afl/
45 https://security.googleblog.com/2016/08/guided-in-process-fuzzing-of-chrome.html
46 */
47
48 #include "config.h"
49 #include "libavutil/avassert.h"
50 #include "libavutil/imgutils.h"
51 #include "libavutil/intreadwrite.h"
52
53 #include "libavcodec/avcodec.h"
54 #include "libavcodec/bytestream.h"
55 #include "libavformat/avformat.h"
56
57 //For FF_SANE_NB_CHANNELS, so we dont waste energy testing things that will get instantly rejected
58 #include "libavcodec/internal.h"
59
60 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
61
62 extern AVCodec * codec_list[];
63
error(const char * err)64 static void error(const char *err)
65 {
66 fprintf(stderr, "%s", err);
67 exit(1);
68 }
69
70 static AVCodec *c = NULL;
AVCodecInitialize(enum AVCodecID codec_id)71 static AVCodec *AVCodecInitialize(enum AVCodecID codec_id)
72 {
73 AVCodec *res;
74
75 res = avcodec_find_decoder(codec_id);
76 if (!res)
77 error("Failed to find decoder");
78 return res;
79 }
80
subtitle_handler(AVCodecContext * avctx,void * frame,int * got_sub_ptr,AVPacket * avpkt)81 static int subtitle_handler(AVCodecContext *avctx, void *frame,
82 int *got_sub_ptr, AVPacket *avpkt)
83 {
84 AVSubtitle sub;
85 int ret = avcodec_decode_subtitle2(avctx, &sub, got_sub_ptr, avpkt);
86 if (ret >= 0 && *got_sub_ptr)
87 avsubtitle_free(&sub);
88 return ret;
89 }
90
91 // Ensure we don't loop forever
92 const uint32_t maxiteration = 8096;
93 const uint64_t maxpixels_per_frame = 4096 * 4096;
94 uint64_t maxpixels;
95
96 uint64_t maxsamples_per_frame = 256*1024*32;
97 uint64_t maxsamples;
98
99 static const uint64_t FUZZ_TAG = 0x4741542D5A5A5546ULL;
100
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)101 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
102 const uint64_t fuzz_tag = FUZZ_TAG;
103 const uint8_t *last = data;
104 const uint8_t *end = data + size;
105 uint32_t it = 0;
106 uint64_t ec_pixels = 0;
107 uint64_t nb_samples = 0;
108 int (*decode_handler)(AVCodecContext *avctx, AVFrame *picture,
109 int *got_picture_ptr,
110 const AVPacket *avpkt) = NULL;
111 AVCodecParserContext *parser = NULL;
112 uint64_t keyframes = 0;
113 AVDictionary *opts = NULL;
114
115 if (!c) {
116 #ifdef FFMPEG_DECODER
117 #define DECODER_SYMBOL0(CODEC) ff_##CODEC##_decoder
118 #define DECODER_SYMBOL(CODEC) DECODER_SYMBOL0(CODEC)
119 extern AVCodec DECODER_SYMBOL(FFMPEG_DECODER);
120 codec_list[0] = &DECODER_SYMBOL(FFMPEG_DECODER);
121 avcodec_register(&DECODER_SYMBOL(FFMPEG_DECODER));
122
123 #if FFMPEG_DECODER == tiff || FFMPEG_DECODER == tdsc
124 extern AVCodec DECODER_SYMBOL(mjpeg);
125 codec_list[1] = &DECODER_SYMBOL(mjpeg);
126 avcodec_register(&DECODER_SYMBOL(mjpeg));
127 #endif
128
129 c = &DECODER_SYMBOL(FFMPEG_DECODER);
130 #else
131 avcodec_register_all();
132 c = AVCodecInitialize(FFMPEG_CODEC); // Done once.
133 #endif
134 av_log_set_level(AV_LOG_PANIC);
135 }
136
137 switch (c->type) {
138 case AVMEDIA_TYPE_AUDIO : decode_handler = avcodec_decode_audio4; break;
139 case AVMEDIA_TYPE_VIDEO : decode_handler = avcodec_decode_video2; break;
140 case AVMEDIA_TYPE_SUBTITLE: decode_handler = subtitle_handler ; break;
141 }
142 switch (c->id) {
143 case AV_CODEC_ID_APE: maxsamples_per_frame /= 256; break;
144 }
145 maxpixels = maxpixels_per_frame * maxiteration;
146 maxsamples = maxsamples_per_frame * maxiteration;
147 switch (c->id) {
148 case AV_CODEC_ID_BINKVIDEO: maxpixels /= 32; break;
149 case AV_CODEC_ID_CFHD: maxpixels /= 128; break;
150 case AV_CODEC_ID_DIRAC: maxpixels /= 8192; break;
151 case AV_CODEC_ID_DST: maxsamples /= 8192; break;
152 case AV_CODEC_ID_DXV: maxpixels /= 32; break;
153 case AV_CODEC_ID_FFWAVESYNTH: maxsamples /= 16384; break;
154 case AV_CODEC_ID_G2M: maxpixels /= 64; break;
155 case AV_CODEC_ID_GDV: maxpixels /= 512; break;
156 case AV_CODEC_ID_GIF: maxpixels /= 16; break;
157 case AV_CODEC_ID_HAP: maxpixels /= 128; break;
158 case AV_CODEC_ID_HEVC: maxpixels /= 16384; break;
159 case AV_CODEC_ID_HNM4_VIDEO: maxpixels /= 128; break;
160 case AV_CODEC_ID_IFF_ILBM: maxpixels /= 128; break;
161 case AV_CODEC_ID_INDEO4: maxpixels /= 128; break;
162 case AV_CODEC_ID_LSCR: maxpixels /= 16; break;
163 case AV_CODEC_ID_MOTIONPIXELS:maxpixels /= 256; break;
164 case AV_CODEC_ID_MP4ALS: maxsamples /= 65536; break;
165 case AV_CODEC_ID_MSRLE: maxpixels /= 16; break;
166 case AV_CODEC_ID_MSS2: maxpixels /= 16384; break;
167 case AV_CODEC_ID_MSZH: maxpixels /= 128; break;
168 case AV_CODEC_ID_PNG: maxpixels /= 128; break;
169 case AV_CODEC_ID_APNG: maxpixels /= 128; break;
170 case AV_CODEC_ID_QTRLE: maxpixels /= 16; break;
171 case AV_CODEC_ID_RASC: maxpixels /= 16; break;
172 case AV_CODEC_ID_SANM: maxpixels /= 16; break;
173 case AV_CODEC_ID_SCPR: maxpixels /= 32; break;
174 case AV_CODEC_ID_SCREENPRESSO:maxpixels /= 64; break;
175 case AV_CODEC_ID_SMACKVIDEO: maxpixels /= 64; break;
176 case AV_CODEC_ID_SNOW: maxpixels /= 128; break;
177 case AV_CODEC_ID_TGV: maxpixels /= 32; break;
178 case AV_CODEC_ID_TRUEMOTION2: maxpixels /= 1024; break;
179 case AV_CODEC_ID_VP7: maxpixels /= 256; break;
180 case AV_CODEC_ID_VP9: maxpixels /= 4096; break;
181 case AV_CODEC_ID_ZEROCODEC: maxpixels /= 128; break;
182 }
183
184
185 AVCodecContext* ctx = avcodec_alloc_context3(c);
186 AVCodecContext* parser_avctx = avcodec_alloc_context3(NULL);
187 if (!ctx || !parser_avctx)
188 error("Failed memory allocation");
189
190 if (ctx->max_pixels == 0 || ctx->max_pixels > maxpixels_per_frame)
191 ctx->max_pixels = maxpixels_per_frame; //To reduce false positive OOM and hangs
192 ctx->refcounted_frames = 1; //To reduce false positive timeouts and focus testing on the refcounted API
193
194 ctx->max_samples = maxsamples_per_frame;
195
196 if (size > 1024) {
197 GetByteContext gbc;
198 int extradata_size;
199 int flags;
200 size -= 1024;
201 bytestream2_init(&gbc, data + size, 1024);
202 ctx->width = bytestream2_get_le32(&gbc);
203 ctx->height = bytestream2_get_le32(&gbc);
204 ctx->bit_rate = bytestream2_get_le64(&gbc);
205 ctx->bits_per_coded_sample = bytestream2_get_le32(&gbc);
206 // Try to initialize a parser for this codec, note, this may fail which just means we test without one
207 flags = bytestream2_get_byte(&gbc);
208 if (flags & 1)
209 parser = av_parser_init(c->id);
210 if (flags & 2)
211 ctx->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;
212 if (flags & 4) {
213 ctx->err_recognition = AV_EF_AGGRESSIVE | AV_EF_COMPLIANT | AV_EF_CAREFUL;
214 if (flags & 8)
215 ctx->err_recognition |= AV_EF_EXPLODE;
216 }
217 if ((flags & 0x10) && c->id != AV_CODEC_ID_H264)
218 ctx->flags2 |= AV_CODEC_FLAG2_FAST;
219
220 if (flags & 0x40)
221 av_force_cpu_flags(0);
222
223 extradata_size = bytestream2_get_le32(&gbc);
224
225 ctx->sample_rate = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
226 ctx->channels = (unsigned)bytestream2_get_le32(&gbc) % FF_SANE_NB_CHANNELS;
227 ctx->block_align = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
228 ctx->codec_tag = bytestream2_get_le32(&gbc);
229 if (c->codec_tags) {
230 int n;
231 for (n = 0; c->codec_tags[n] != FF_CODEC_TAGS_END; n++);
232 ctx->codec_tag = c->codec_tags[ctx->codec_tag % n];
233 }
234 keyframes = bytestream2_get_le64(&gbc);
235 ctx->request_channel_layout = bytestream2_get_le64(&gbc);
236
237 ctx->idct_algo = bytestream2_get_byte(&gbc) % 25;
238
239 if (flags & 0x20) {
240 switch (ctx->codec_id) {
241 case AV_CODEC_ID_AC3:
242 case AV_CODEC_ID_EAC3:
243 av_dict_set_int(&opts, "cons_noisegen", bytestream2_get_byte(&gbc) & 1, 0);
244 av_dict_set_int(&opts, "heavy_compr", bytestream2_get_byte(&gbc) & 1, 0);
245 av_dict_set_int(&opts, "target_level", (int)(bytestream2_get_byte(&gbc) % 32) - 31, 0);
246 av_dict_set_int(&opts, "dmix_mode", (int)(bytestream2_get_byte(&gbc) % 4) - 1, 0);
247 break;
248 }
249 }
250
251
252 if (extradata_size < size) {
253 ctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
254 if (ctx->extradata) {
255 ctx->extradata_size = extradata_size;
256 size -= ctx->extradata_size;
257 memcpy(ctx->extradata, data + size, ctx->extradata_size);
258 }
259 }
260 if (av_image_check_size(ctx->width, ctx->height, 0, ctx))
261 ctx->width = ctx->height = 0;
262 }
263
264 int res = avcodec_open2(ctx, c, &opts);
265 if (res < 0) {
266 avcodec_free_context(&ctx);
267 av_free(parser_avctx);
268 av_parser_close(parser);
269 av_dict_free(&opts);
270 return 0; // Failure of avcodec_open2() does not imply that a issue was found
271 }
272 parser_avctx->codec_id = ctx->codec_id;
273
274 int got_frame;
275 AVFrame *frame = av_frame_alloc();
276 if (!frame)
277 error("Failed memory allocation");
278
279 // Read very simple container
280 AVPacket avpkt, parsepkt;
281 av_init_packet(&avpkt);
282 av_init_packet(&parsepkt);
283 while (data < end && it < maxiteration) {
284 // Search for the TAG
285 while (data + sizeof(fuzz_tag) < end) {
286 if (data[0] == (fuzz_tag & 0xFF) && AV_RN64(data) == fuzz_tag)
287 break;
288 data++;
289 }
290 if (data + sizeof(fuzz_tag) > end)
291 data = end;
292
293 res = av_new_packet(&parsepkt, data - last);
294 if (res < 0)
295 error("Failed memory allocation");
296 memcpy(parsepkt.data, last, data - last);
297 parsepkt.flags = (keyframes & 1) * AV_PKT_FLAG_DISCARD + (!!(keyframes & 2)) * AV_PKT_FLAG_KEY;
298 keyframes = (keyframes >> 2) + (keyframes<<62);
299 data += sizeof(fuzz_tag);
300 last = data;
301
302 while (parsepkt.size > 0) {
303
304 if (parser) {
305 av_init_packet(&avpkt);
306 int ret = av_parser_parse2(parser, parser_avctx, &avpkt.data, &avpkt.size,
307 parsepkt.data, parsepkt.size,
308 parsepkt.pts, parsepkt.dts, parsepkt.pos);
309 if (avpkt.data == parsepkt.data) {
310 avpkt.buf = av_buffer_ref(parsepkt.buf);
311 if (!avpkt.buf)
312 error("Failed memory allocation");
313 } else {
314 if (av_packet_make_refcounted(&avpkt) < 0)
315 error("Failed memory allocation");
316 }
317 parsepkt.data += ret;
318 parsepkt.size -= ret;
319 parsepkt.pos += ret;
320 avpkt.pts = parser->pts;
321 avpkt.dts = parser->dts;
322 avpkt.pos = parser->pos;
323 if ( parser->key_frame == 1 ||
324 (parser->key_frame == -1 && parser->pict_type == AV_PICTURE_TYPE_I))
325 avpkt.flags |= AV_PKT_FLAG_KEY;
326 avpkt.flags |= parsepkt.flags & AV_PKT_FLAG_DISCARD;
327 } else {
328 av_packet_move_ref(&avpkt, &parsepkt);
329 }
330
331 // Iterate through all data
332 while (avpkt.size > 0 && it++ < maxiteration) {
333 av_frame_unref(frame);
334 int ret = decode_handler(ctx, frame, &got_frame, &avpkt);
335
336 ec_pixels += (ctx->width + 32LL) * (ctx->height + 32LL);
337 if (it > 20 || ec_pixels > 4 * ctx->max_pixels)
338 ctx->error_concealment = 0;
339 if (ec_pixels > maxpixels)
340 goto maximums_reached;
341
342 nb_samples += frame->nb_samples;
343 if (nb_samples > maxsamples)
344 goto maximums_reached;
345
346 if (ret <= 0 || ret > avpkt.size)
347 break;
348 if (ctx->codec_type != AVMEDIA_TYPE_AUDIO)
349 ret = avpkt.size;
350 avpkt.data += ret;
351 avpkt.size -= ret;
352 }
353 av_packet_unref(&avpkt);
354 }
355 av_packet_unref(&parsepkt);
356 }
357 maximums_reached:
358
359 av_packet_unref(&avpkt);
360
361 do {
362 got_frame = 0;
363 av_frame_unref(frame);
364 decode_handler(ctx, frame, &got_frame, &avpkt);
365 } while (got_frame == 1 && it++ < maxiteration);
366
367 fprintf(stderr, "pixels decoded: %"PRId64", samples decoded: %"PRId64", iterations: %d\n", ec_pixels, nb_samples, it);
368
369 av_frame_free(&frame);
370 avcodec_free_context(&ctx);
371 avcodec_free_context(&parser_avctx);
372 av_parser_close(parser);
373 av_packet_unref(&parsepkt);
374 av_dict_free(&opts);
375 return 0;
376 }
377