tools/target_dec_fuzzer.c

   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
  64 static void error(const char *err)
  65 {
  66     fprintf(stderr, "%s", err);
  67     exit(1);
  68 }
  69
  70 static AVCodec *c = NULL;
  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
  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
 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_H264:        maxpixels  /= 256;   break;
 158     case AV_CODEC_ID_HAP:         maxpixels  /= 128;   break;
 159     case AV_CODEC_ID_HEVC:        maxpixels  /= 16384; break;
 160     case AV_CODEC_ID_HNM4_VIDEO:  maxpixels  /= 128;   break;
 161     case AV_CODEC_ID_IFF_ILBM:    maxpixels  /= 128;   break;
 162     case AV_CODEC_ID_INDEO4:      maxpixels  /= 128;   break;
 163     case AV_CODEC_ID_LSCR:        maxpixels  /= 16;    break;
 164     case AV_CODEC_ID_MMVIDEO:     maxpixels  /= 256;   break;
 165     case AV_CODEC_ID_MOTIONPIXELS:maxpixels  /= 256;   break;
 166     case AV_CODEC_ID_MP4ALS:      maxsamples /= 65536; break;
 167     case AV_CODEC_ID_MSRLE:       maxpixels  /= 16;    break;
 168     case AV_CODEC_ID_MSS2:        maxpixels  /= 16384; break;
 169     case AV_CODEC_ID_MSZH:        maxpixels  /= 128;   break;
 170     case AV_CODEC_ID_PNG:         maxpixels  /= 128;   break;
 171     case AV_CODEC_ID_APNG:        maxpixels  /= 128;   break;
 172     case AV_CODEC_ID_QTRLE:       maxpixels  /= 16;    break;
 173     case AV_CODEC_ID_RASC:        maxpixels  /= 16;    break;
 174     case AV_CODEC_ID_RTV1:        maxpixels  /= 16;    break;
 175     case AV_CODEC_ID_SANM:        maxpixels  /= 16;    break;
 176     case AV_CODEC_ID_SCPR:        maxpixels  /= 32;    break;
 177     case AV_CODEC_ID_SCREENPRESSO:maxpixels  /= 64;    break;
 178     case AV_CODEC_ID_SMACKVIDEO:  maxpixels  /= 64;    break;
 179     case AV_CODEC_ID_SNOW:        maxpixels  /= 128;   break;
 180     case AV_CODEC_ID_TGV:         maxpixels  /= 32;    break;
 181     case AV_CODEC_ID_TRUEMOTION2: maxpixels  /= 1024;  break;
 182     case AV_CODEC_ID_VP7:         maxpixels  /= 256;   break;
 183     case AV_CODEC_ID_VP9:         maxpixels  /= 4096;  break;
 184     case AV_CODEC_ID_ZEROCODEC:   maxpixels  /= 128;   break;
 185     }
 186
 187
 188     AVCodecContext* ctx = avcodec_alloc_context3(c);
 189     AVCodecContext* parser_avctx = avcodec_alloc_context3(NULL);
 190     if (!ctx || !parser_avctx)
 191         error("Failed memory allocation");
 192
 193     if (ctx->max_pixels == 0 || ctx->max_pixels > maxpixels_per_frame)
 194         ctx->max_pixels = maxpixels_per_frame; //To reduce false positive OOM and hangs
 195     ctx->refcounted_frames = 1; //To reduce false positive timeouts and focus testing on the refcounted API
 196
 197     ctx->max_samples = maxsamples_per_frame;
 198
 199     if (size > 1024) {
 200         GetByteContext gbc;
 201         int extradata_size;
 202         int flags;
 203         size -= 1024;
 204         bytestream2_init(&gbc, data + size, 1024);
 205         ctx->width                              = bytestream2_get_le32(&gbc);
 206         ctx->height                             = bytestream2_get_le32(&gbc);
 207         ctx->bit_rate                           = bytestream2_get_le64(&gbc);
 208         ctx->bits_per_coded_sample              = bytestream2_get_le32(&gbc);
 209         // Try to initialize a parser for this codec, note, this may fail which just means we test without one
 210         flags = bytestream2_get_byte(&gbc);
 211         if (flags & 1)
 212             parser = av_parser_init(c->id);
 213         if (flags & 2)
 214             ctx->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;
 215         if (flags & 4) {
 216             ctx->err_recognition = AV_EF_AGGRESSIVE | AV_EF_COMPLIANT | AV_EF_CAREFUL;
 217             if (flags & 8)
 218                 ctx->err_recognition |= AV_EF_EXPLODE;
 219         }
 220         if ((flags & 0x10) && c->id != AV_CODEC_ID_H264)
 221             ctx->flags2 |= AV_CODEC_FLAG2_FAST;
 222
 223         if (flags & 0x40)
 224             av_force_cpu_flags(0);
 225
 226         extradata_size = bytestream2_get_le32(&gbc);
 227
 228         ctx->sample_rate                        = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
 229         ctx->channels                           = (unsigned)bytestream2_get_le32(&gbc) % FF_SANE_NB_CHANNELS;
 230         ctx->block_align                        = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
 231         ctx->codec_tag                          = bytestream2_get_le32(&gbc);
 232         if (c->codec_tags) {
 233             int n;
 234             for (n = 0; c->codec_tags[n] != FF_CODEC_TAGS_END; n++);
 235             ctx->codec_tag = c->codec_tags[ctx->codec_tag % n];
 236         }
 237         keyframes                               = bytestream2_get_le64(&gbc);
 238         ctx->request_channel_layout             = bytestream2_get_le64(&gbc);
 239
 240         ctx->idct_algo                          = bytestream2_get_byte(&gbc) % 25;
 241
 242         if (flags & 0x20) {
 243             switch (ctx->codec_id) {
 244             case AV_CODEC_ID_AC3:
 245             case AV_CODEC_ID_EAC3:
 246                 av_dict_set_int(&opts, "cons_noisegen", bytestream2_get_byte(&gbc) & 1, 0);
 247                 av_dict_set_int(&opts, "heavy_compr",   bytestream2_get_byte(&gbc) & 1, 0);
 248                 av_dict_set_int(&opts, "target_level",  (int)(bytestream2_get_byte(&gbc) % 32) - 31, 0);
 249                 av_dict_set_int(&opts, "dmix_mode",     (int)(bytestream2_get_byte(&gbc) %  4) -  1, 0);
 250                 break;
 251             }
 252         }
 253
 254
 255         if (extradata_size < size) {
 256             ctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
 257             if (ctx->extradata) {
 258                 ctx->extradata_size = extradata_size;
 259                 size -= ctx->extradata_size;
 260                 memcpy(ctx->extradata, data + size, ctx->extradata_size);
 261             }
 262         }
 263         if (av_image_check_size(ctx->width, ctx->height, 0, ctx))
 264             ctx->width = ctx->height = 0;
 265     }
 266
 267     int res = avcodec_open2(ctx, c, &opts);
 268     if (res < 0) {
 269         avcodec_free_context(&ctx);
 270         av_free(parser_avctx);
 271         av_parser_close(parser);
 272         av_dict_free(&opts);
 273         return 0; // Failure of avcodec_open2() does not imply that a issue was found
 274     }
 275     parser_avctx->codec_id = ctx->codec_id;
 276
 277     int got_frame;
 278     AVFrame *frame = av_frame_alloc();
 279     if (!frame)
 280         error("Failed memory allocation");
 281
 282     // Read very simple container
 283     AVPacket avpkt, parsepkt;
 284     av_init_packet(&avpkt);
 285     av_init_packet(&parsepkt);
 286     while (data < end && it < maxiteration) {
 287         // Search for the TAG
 288         while (data + sizeof(fuzz_tag) < end) {
 289             if (data[0] == (fuzz_tag & 0xFF) && AV_RN64(data) == fuzz_tag)
 290                 break;
 291             data++;
 292         }
 293         if (data + sizeof(fuzz_tag) > end)
 294             data = end;
 295
 296         res = av_new_packet(&parsepkt, data - last);
 297         if (res < 0)
 298             error("Failed memory allocation");
 299         memcpy(parsepkt.data, last, data - last);
 300         parsepkt.flags = (keyframes & 1) * AV_PKT_FLAG_DISCARD + (!!(keyframes & 2)) * AV_PKT_FLAG_KEY;
 301         keyframes = (keyframes >> 2) + (keyframes<<62);
 302         data += sizeof(fuzz_tag);
 303         last = data;
 304
 305         while (parsepkt.size > 0) {
 306
 307             if (parser) {
 308                 av_init_packet(&avpkt);
 309                 int ret = av_parser_parse2(parser, parser_avctx, &avpkt.data, &avpkt.size,
 310                                            parsepkt.data, parsepkt.size,
 311                                            parsepkt.pts, parsepkt.dts, parsepkt.pos);
 312                 if (avpkt.data == parsepkt.data) {
 313                     avpkt.buf = av_buffer_ref(parsepkt.buf);
 314                     if (!avpkt.buf)
 315                         error("Failed memory allocation");
 316                 } else {
 317                     if (av_packet_make_refcounted(&avpkt) < 0)
 318                         error("Failed memory allocation");
 319                 }
 320                 parsepkt.data += ret;
 321                 parsepkt.size -= ret;
 322                 parsepkt.pos  += ret;
 323                 avpkt.pts = parser->pts;
 324                 avpkt.dts = parser->dts;
 325                 avpkt.pos = parser->pos;
 326                 if ( parser->key_frame == 1 ||
 327                     (parser->key_frame == -1 && parser->pict_type == AV_PICTURE_TYPE_I))
 328                     avpkt.flags |= AV_PKT_FLAG_KEY;
 329                 avpkt.flags |= parsepkt.flags & AV_PKT_FLAG_DISCARD;
 330             } else {
 331                 av_packet_move_ref(&avpkt, &parsepkt);
 332             }
 333
 334           // Iterate through all data
 335           while (avpkt.size > 0 && it++ < maxiteration) {
 336             av_frame_unref(frame);
 337             int ret = decode_handler(ctx, frame, &got_frame, &avpkt);
 338
 339             ec_pixels += (ctx->width + 32LL) * (ctx->height + 32LL);
 340             if (it > 20 || ec_pixels > 4 * ctx->max_pixels)
 341                 ctx->error_concealment = 0;
 342             if (ec_pixels > maxpixels)
 343                 goto maximums_reached;
 344
 345             nb_samples += frame->nb_samples;
 346             if (nb_samples > maxsamples)
 347                 goto maximums_reached;
 348
 349             if (ret <= 0 || ret > avpkt.size)
 350                break;
 351             if (ctx->codec_type != AVMEDIA_TYPE_AUDIO)
 352                 ret = avpkt.size;
 353             avpkt.data += ret;
 354             avpkt.size -= ret;
 355           }
 356           av_packet_unref(&avpkt);
 357         }
 358         av_packet_unref(&parsepkt);
 359     }
 360 maximums_reached:
 361
 362     av_packet_unref(&avpkt);
 363
 364     do {
 365         got_frame = 0;
 366         av_frame_unref(frame);
 367         decode_handler(ctx, frame, &got_frame, &avpkt);
 368     } while (got_frame == 1 && it++ < maxiteration);
 369
 370     fprintf(stderr, "pixels decoded: %"PRId64", samples decoded: %"PRId64", iterations: %d\n", ec_pixels, nb_samples, it);
 371
 372     av_frame_free(&frame);
 373     avcodec_free_context(&ctx);
 374     avcodec_free_context(&parser_avctx);
 375     av_parser_close(parser);
 376     av_packet_unref(&parsepkt);
 377     av_dict_free(&opts);
 378     return 0;
 379 }