avcodec/snowdec: Sanity check hcoeff

Fixes: signed integer overflow: -2147483648 * -1 cannot be represented in type 'int'
Fixes: 24011/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SNOW_fuzzer-5486376610168832

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 2020-08-06 21:35:06 +02:00
parent fab00b0ae0
commit d51d569cf6

View File

@ -369,7 +369,10 @@ static int decode_header(SnowContext *s){
htaps = htaps*2 + 2;
p->htaps= htaps;
for(i= htaps/2; i; i--){
p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
unsigned hcoeff = get_symbol(&s->c, s->header_state, 0);
if (hcoeff > 127)
return AVERROR_INVALIDDATA;
p->hcoeff[i]= hcoeff * (1-2*(i&1));
sum += p->hcoeff[i];
}
p->hcoeff[0]= 32-sum;