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| author | Michael Niedermayer <michael@niedermayer.cc> | 2017-05-11 19:10:16 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2017-05-14 12:20:16 +0200 |
| commit | 54eaad7c6e321dc2ba1cc9e973b4f49d74a3e20a (patch) | |
| tree | f9bf899d7859e11f0c9c98533032471eec4bc71e | |
| parent | af52a28f4dd2cd536f066e630d618a0405a37b93 (diff) | |
| download | ffmpeg-54eaad7c6e321dc2ba1cc9e973b4f49d74a3e20a.tar.gz | |
avcodec/msmpeg4dec: Check for cbpy VLC errors
Fixes: runtime error: left shift of negative value -1
Fixes: 1480/clusterfuzz-testcase-minimized-5188321007370240
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 15e892aad12b23e9b5686cf66ca6fa739c734ead)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/msmpeg4dec.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/libavcodec/msmpeg4dec.c b/libavcodec/msmpeg4dec.c index b464092d88..26f292806f 100644 --- a/libavcodec/msmpeg4dec.c +++ b/libavcodec/msmpeg4dec.c @@ -169,12 +169,23 @@ static int msmpeg4v12_decode_mb(MpegEncContext *s, int16_t block[6][64]) s->mv[0][0][1] = my; *mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16; } else { + int v; if(s->msmpeg4_version==2){ s->ac_pred = get_bits1(&s->gb); - cbp|= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors + v = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1); + if (v < 0) { + av_log(s->avctx, AV_LOG_ERROR, "cbpy vlc invalid\n"); + return -1; + } + cbp|= v<<2; } else{ s->ac_pred = 0; - cbp|= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors + v = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1); + if (v < 0) { + av_log(s->avctx, AV_LOG_ERROR, "cbpy vlc invalid\n"); + return -1; + } + cbp|= v<<2; if(s->pict_type==AV_PICTURE_TYPE_P) cbp^=0x3C; } *mb_type_ptr = MB_TYPE_INTRA; |