avcodec/pnmdec: Use unsigned for maxval rescaling

Fixes: signed integer overflow: 65535 * 55335 cannot be represented in type 'int'
Fixes: 21955/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PGMYUV_fuzzer-5669206981083136

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 2020-05-16 00:31:23 +02:00
parent 1d633e6a0a
commit 49459aca47

View File

@ -132,7 +132,7 @@ static int pnm_decode_frame(AVCodecContext *avctx, void *data,
init_put_bits(&pb, ptr, linesize);
for(j=0; j<avctx->width * components; j++){
unsigned int c=0;
int v=0;
unsigned v=0;
if(s->type < 4)
while(s->bytestream < s->bytestream_end && (*s->bytestream < '0' || *s->bytestream > '9' ))
s->bytestream++;