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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-08-01 20:04:15 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-08-23 22:26:50 +0200 |
| commit | 1a0f106232f51cd20dc0ebab2c02de49ba26fa6b (patch) | |
| tree | 9be814621ec52159fceadc82b65dcad896e5d318 | |
| parent | 77abf3145344341ec850e05d25a849c6f76fffa5 (diff) | |
| download | ffmpeg-1a0f106232f51cd20dc0ebab2c02de49ba26fa6b.tar.gz | |
avcodec/pnm: Check magic bytes directly without pnm_get()
Fixes: Timeout (10sec -> 30ms) (case 15089)
Fixes: 15089/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PBM_fuzzer-5767535057698816
Fixes: 16001/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PGM_fuzzer-5199169645445120
Fixes: 16003/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PGMYUV_fuzzer-5076443270217728
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/pnm.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/libavcodec/pnm.c b/libavcodec/pnm.c index a9771710c2..cadfa7569e 100644 --- a/libavcodec/pnm.c +++ b/libavcodec/pnm.c @@ -22,6 +22,7 @@ #include <stdlib.h> #include <string.h> +#include "libavutil/avassert.h" #include "libavutil/imgutils.h" #include "avcodec.h" #include "internal.h" @@ -68,9 +69,15 @@ int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s) int h, w, depth, maxval; int ret; - pnm_get(s, buf1, sizeof(buf1)); - if(buf1[0] != 'P') + if (s->bytestream_end - s->bytestream < 3 || + s->bytestream[0] != 'P' || + s->bytestream[1] < '1' || + s->bytestream[1] > '7') { + s->bytestream += s->bytestream_end > s->bytestream; + s->bytestream += s->bytestream_end > s->bytestream; return AVERROR_INVALIDDATA; + } + pnm_get(s, buf1, sizeof(buf1)); s->type= buf1[1]-'0'; if (s->type==1 || s->type==4) { @@ -152,7 +159,7 @@ int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s) } return 0; } else { - return AVERROR_INVALIDDATA; + av_assert0(0); } pnm_get(s, buf1, sizeof(buf1)); w = atoi(buf1); |