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authorMichael Niedermayer <michael@niedermayer.cc>2017-05-11 19:10:16 +0200
committerMichael Niedermayer <michael@niedermayer.cc>2017-05-11 20:04:57 +0200
commit15e892aad12b23e9b5686cf66ca6fa739c734ead (patch)
tree0aad54e058075bbfd4fc98f2d458527957b20a79 /libavcodec/msmpeg4dec.c
parent2bfd0a97587d26c0c39413a6291ccc66e4a928d0 (diff)
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>
Diffstat (limited to 'libavcodec/msmpeg4dec.c')
-rw-r--r--libavcodec/msmpeg4dec.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/libavcodec/msmpeg4dec.c b/libavcodec/msmpeg4dec.c
index b5bc36ece2..4105d4ba7d 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;