avcodec/snowdec: Check mv_scale

Fixes: runtime error: signed integer overflow: 2 * -1094995530 cannot be represented in type 'int'
Fixes: 3512/clusterfuzz-testcase-minimized-4812747210489856

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-10-13 03:06:54 +02:00
parent 9c85329cd0
commit 393d6fc739
1 changed files with 2 additions and 1 deletions

View File

@ -394,9 +394,10 @@ static int decode_header(SnowContext *s){
s->mv_scale += get_symbol(&s->c, s->header_state, 1);
s->qbias += get_symbol(&s->c, s->header_state, 1);
s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
if(s->block_max_depth > 1 || s->block_max_depth < 0){
if(s->block_max_depth > 1 || s->block_max_depth < 0 || s->mv_scale > 256U){
av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
s->block_max_depth= 0;
s->mv_scale = 0;
return AVERROR_INVALIDDATA;
}
if (FFABS(s->qbias) > 127) {