2 * This file is part of FFmpeg.
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.
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.
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
19 /* Targeted fuzzer that targets specific codecs depending on two
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
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
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
38 ./target_dec_fuzzer -max_len=100000 CORPUS
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
49 #include "libavutil/avassert.h"
50 #include "libavutil/imgutils.h"
51 #include "libavutil/intreadwrite.h"
53 #include "libavcodec/avcodec.h"
54 #include "libavcodec/bytestream.h"
55 #include "libavformat/avformat.h"
57 //For FF_SANE_NB_CHANNELS, so we dont waste energy testing things that will get instantly rejected
58 #include "libavcodec/internal.h"
60 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
62 extern AVCodec * codec_list[];
64 static void error(const char *err)
66 fprintf(stderr, "%s", err);
70 static AVCodec *c = NULL;
71 static AVCodec *AVCodecInitialize(enum AVCodecID codec_id)
75 res = avcodec_find_decoder(codec_id);
77 error("Failed to find decoder");
81 static int subtitle_handler(AVCodecContext *avctx, void *frame,
82 int *got_sub_ptr, AVPacket *avpkt)
85 int ret = avcodec_decode_subtitle2(avctx, &sub, got_sub_ptr, avpkt);
86 if (ret >= 0 && *got_sub_ptr)
87 avsubtitle_free(&sub);
91 // Ensure we don't loop forever
92 const uint32_t maxiteration = 8096;
93 const uint64_t maxpixels_per_frame = 4096 * 4096;
96 const uint64_t maxsamples_per_frame = 256*1024*32;
99 static const uint64_t FUZZ_TAG = 0x4741542D5A5A5546ULL;
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;
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;
115 #ifdef FFMPEG_DECODER
116 #define DECODER_SYMBOL0(CODEC) ff_##CODEC##_decoder
117 #define DECODER_SYMBOL(CODEC) DECODER_SYMBOL0(CODEC)
118 extern AVCodec DECODER_SYMBOL(FFMPEG_DECODER);
119 codec_list[0] = &DECODER_SYMBOL(FFMPEG_DECODER);
120 avcodec_register(&DECODER_SYMBOL(FFMPEG_DECODER));
122 c = &DECODER_SYMBOL(FFMPEG_DECODER);
124 avcodec_register_all();
125 c = AVCodecInitialize(FFMPEG_CODEC); // Done once.
127 av_log_set_level(AV_LOG_PANIC);
131 case AVMEDIA_TYPE_AUDIO : decode_handler = avcodec_decode_audio4; break;
132 case AVMEDIA_TYPE_VIDEO : decode_handler = avcodec_decode_video2; break;
133 case AVMEDIA_TYPE_SUBTITLE: decode_handler = subtitle_handler ; break;
135 maxpixels = maxpixels_per_frame * maxiteration;
136 maxsamples = maxsamples_per_frame * maxiteration;
138 // Allows a small input to generate gigantic output
139 case AV_CODEC_ID_BINKVIDEO: maxpixels /= 32; break;
140 case AV_CODEC_ID_DIRAC: maxpixels /= 8192; break;
141 case AV_CODEC_ID_MSRLE: maxpixels /= 16; break;
142 case AV_CODEC_ID_QTRLE: maxpixels /= 16; break;
143 case AV_CODEC_ID_SANM: maxpixels /= 16; break;
144 case AV_CODEC_ID_GIF: maxpixels /= 16; break;
145 // Performs slow frame rescaling in C
146 case AV_CODEC_ID_GDV: maxpixels /= 512; break;
147 // Postprocessing in C
148 case AV_CODEC_ID_HNM4_VIDEO:maxpixels /= 128; break;
149 // Cliping in C, generally slow even with small input
150 case AV_CODEC_ID_INDEO4: maxpixels /= 128; break;
151 case AV_CODEC_ID_LSCR: maxpixels /= 16; break;
152 case AV_CODEC_ID_MOTIONPIXELS:maxpixels /= 256; break;
153 case AV_CODEC_ID_MSS2: maxpixels /= 16384; break;
154 case AV_CODEC_ID_SNOW: maxpixels /= 128; break;
155 case AV_CODEC_ID_TRUEMOTION2: maxpixels /= 1024; break;
159 AVCodecContext* ctx = avcodec_alloc_context3(c);
160 AVCodecContext* parser_avctx = avcodec_alloc_context3(NULL);
161 if (!ctx || !parser_avctx)
162 error("Failed memory allocation");
164 if (ctx->max_pixels == 0 || ctx->max_pixels > maxpixels_per_frame)
165 ctx->max_pixels = maxpixels_per_frame; //To reduce false positive OOM and hangs
166 ctx->refcounted_frames = 1; //To reduce false positive timeouts and focus testing on the refcounted API
168 ctx->max_samples = maxsamples_per_frame;
174 bytestream2_init(&gbc, data + size, 1024);
175 ctx->width = bytestream2_get_le32(&gbc);
176 ctx->height = bytestream2_get_le32(&gbc);
177 ctx->bit_rate = bytestream2_get_le64(&gbc);
178 ctx->bits_per_coded_sample = bytestream2_get_le32(&gbc);
179 // Try to initialize a parser for this codec, note, this may fail which just means we test without one
180 if (bytestream2_get_byte(&gbc) & 1)
181 parser = av_parser_init(c->id);
183 extradata_size = bytestream2_get_le32(&gbc);
185 ctx->sample_rate = bytestream2_get_le32(&gbc);
186 ctx->channels = (unsigned)bytestream2_get_le32(&gbc) % FF_SANE_NB_CHANNELS;
188 if (extradata_size < size) {
189 ctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
190 if (ctx->extradata) {
191 ctx->extradata_size = extradata_size;
192 size -= ctx->extradata_size;
193 memcpy(ctx->extradata, data + size, ctx->extradata_size);
196 if (av_image_check_size(ctx->width, ctx->height, 0, ctx))
197 ctx->width = ctx->height = 0;
200 int res = avcodec_open2(ctx, c, NULL);
202 avcodec_free_context(&ctx);
203 av_free(parser_avctx);
204 av_parser_close(parser);
205 return 0; // Failure of avcodec_open2() does not imply that a issue was found
207 parser_avctx->codec_id = ctx->codec_id;
210 AVFrame *frame = av_frame_alloc();
212 error("Failed memory allocation");
214 // Read very simple container
215 AVPacket avpkt, parsepkt;
216 av_init_packet(&avpkt);
217 av_init_packet(&parsepkt);
218 while (data < end && it < maxiteration) {
219 // Search for the TAG
220 while (data + sizeof(fuzz_tag) < end) {
221 if (data[0] == (fuzz_tag & 0xFF) && AV_RN64(data) == fuzz_tag)
225 if (data + sizeof(fuzz_tag) > end)
228 res = av_new_packet(&parsepkt, data - last);
230 error("Failed memory allocation");
231 memcpy(parsepkt.data, last, data - last);
232 data += sizeof(fuzz_tag);
235 while (parsepkt.size > 0) {
238 av_init_packet(&avpkt);
239 int ret = av_parser_parse2(parser, parser_avctx, &avpkt.data, &avpkt.size,
240 parsepkt.data, parsepkt.size,
241 parsepkt.pts, parsepkt.dts, parsepkt.pos);
242 if (avpkt.data == parsepkt.data) {
243 avpkt.buf = av_buffer_ref(parsepkt.buf);
245 error("Failed memory allocation");
247 if (av_packet_make_refcounted(&avpkt) < 0)
248 error("Failed memory allocation");
250 parsepkt.data += ret;
251 parsepkt.size -= ret;
253 avpkt.pts = parser->pts;
254 avpkt.dts = parser->dts;
255 avpkt.pos = parser->pos;
256 if ( parser->key_frame == 1 ||
257 (parser->key_frame == -1 && parser->pict_type == AV_PICTURE_TYPE_I))
258 avpkt.flags |= AV_PKT_FLAG_KEY;
259 avpkt.flags |= parsepkt.flags & AV_PKT_FLAG_DISCARD;
261 av_packet_move_ref(&avpkt, &parsepkt);
264 // Iterate through all data
265 while (avpkt.size > 0 && it++ < maxiteration) {
266 av_frame_unref(frame);
267 int ret = decode_handler(ctx, frame, &got_frame, &avpkt);
269 ec_pixels += (ctx->width + 32LL) * (ctx->height + 32LL);
270 if (it > 20 || ec_pixels > 4 * ctx->max_pixels)
271 ctx->error_concealment = 0;
272 if (ec_pixels > maxpixels)
273 goto maximums_reached;
275 nb_samples += frame->nb_samples;
276 if (nb_samples > maxsamples)
277 goto maximums_reached;
279 if (ret <= 0 || ret > avpkt.size)
281 if (ctx->codec_type != AVMEDIA_TYPE_AUDIO)
286 av_packet_unref(&avpkt);
288 av_packet_unref(&parsepkt);
292 av_packet_unref(&avpkt);
296 av_frame_unref(frame);
297 decode_handler(ctx, frame, &got_frame, &avpkt);
298 } while (got_frame == 1 && it++ < maxiteration);
300 fprintf(stderr, "pixels decoded: %"PRId64", iterations: %d\n", ec_pixels, it);
302 av_frame_free(&frame);
303 avcodec_free_context(&ctx);
304 avcodec_free_context(&parser_avctx);
305 av_parser_close(parser);
306 av_packet_unref(&parsepkt);