avcodec/webp: Fix signedness in prefix_code check

Fixes: out of array read
Fixes: 1557/clusterfuzz-testcase-minimized-6535013757616128

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-05-13 23:21:24 +02:00
parent 86b1b0d33d
commit 8c5cd1c9d3
1 changed files with 1 additions and 1 deletions

View File

@ -694,7 +694,7 @@ static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role,
length = offset + get_bits(&s->gb, extra_bits) + 1;
}
prefix_code = huff_reader_get_symbol(&hg[HUFF_IDX_DIST], &s->gb);
if (prefix_code > 39) {
if (prefix_code > 39U) {
av_log(s->avctx, AV_LOG_ERROR,
"distance prefix code too large: %d\n", prefix_code);
return AVERROR_INVALIDDATA;