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| author | Michael Niedermayer <michael@niedermayer.cc> | 2021-08-31 20:15:09 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2021-10-06 14:41:42 +0200 |
| commit | b66384b77fb596e7b110cf7b493fffd6c45a9d85 (patch) | |
| tree | f23074617871fd15a22d7a9e7f35d966ab638ac1 | |
| parent | 6238b5bab5c6c009c68dcda9b052faac122ad741 (diff) | |
| download | ffmpeg-b66384b77fb596e7b110cf7b493fffd6c45a9d85.tar.gz | |
avcodec/mpeg12dec: Do not put mpeg_f_code into an invalid state on error return
Fixes: invalid shift
Fixes: 37018/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG2VIDEO_fuzzer-5290280902328320
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 5a95abcce4d93f979e4b53f2220f7a54edd03312)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/mpeg12dec.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c index 99e56532a5..85e755d5dd 100644 --- a/libavcodec/mpeg12dec.c +++ b/libavcodec/mpeg12dec.c @@ -1545,6 +1545,10 @@ static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1) s->mpeg_f_code[0][1] = get_bits(&s->gb, 4); s->mpeg_f_code[1][0] = get_bits(&s->gb, 4); s->mpeg_f_code[1][1] = get_bits(&s->gb, 4); + s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0]; + s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1]; + s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0]; + s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1]; if (!s->pict_type && s1->mpeg_enc_ctx_allocated) { av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n"); @@ -1558,10 +1562,6 @@ static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1) s->current_picture.f->pict_type = s->pict_type; s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I; } - s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0]; - s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1]; - s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0]; - s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1]; s->intra_dc_precision = get_bits(&s->gb, 2); s->picture_structure = get_bits(&s->gb, 2); |