[FFmpeg-cvslog] avcodec/webp: Check available space in loop in decode_entropy_coded_image()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Jul 25 15:50:54 2021 +0200| [5e00eab61112c52f27a09fe77d50e6fc508f9c53] | committer: Michael Niedermayer

avcodec/webp: Check available space in loop in decode_entropy_coded_image()

Fixes: Timeout
Fixes: 35401/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WEBP_fuzzer-5714401821851648

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5e00eab61112c52f27a09fe77d50e6fc508f9c53
---

 libavcodec/webp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/webp.c b/libavcodec/webp.c
index 83371ef6fd..3efd4438d9 100644
--- a/libavcodec/webp.c
+++ b/libavcodec/webp.c
@@ -627,6 +627,9 @@ static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role,
     while (y < img->frame->height) {
         int v;
 
+        if (get_bits_left(&s->gb) < 0)
+            return AVERROR_INVALIDDATA;
+
         hg = get_huffman_group(s, img, x, y);
         v = huff_reader_get_symbol(&hg[HUFF_IDX_GREEN], &s->gb);
         if (v < NUM_LITERAL_CODES) {