[FFmpeg-devel] [PATCH 1/5] avcodec/vp56: Consider the alpha start as end of the prior header

[Michael Niedermayer]

Fixes: Timeout (23sec -> 71ms)
Fixes: 15661/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VP6A_fuzzer-6257865947348992

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/vp56.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/vp56.c b/libavcodec/vp56.c
index 72fea3780e..695f37e972 100644
--- a/libavcodec/vp56.c
+++ b/libavcodec/vp56.c
@@ -572,7 +572,7 @@ int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
     VP56Context *s = avctx->priv_data;
     AVFrame *const p = s->frames[VP56_FRAME_CURRENT];
     int remaining_buf_size = avpkt->size;
-    int av_uninit(alpha_offset);
+    int alpha_offset = remaining_buf_size;
     int i, res;
     int ret;
 
@@ -585,7 +585,7 @@ int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
             return AVERROR_INVALIDDATA;
     }
 
-    res = s->parse_header(s, buf, remaining_buf_size);
+    res = s->parse_header(s, buf, alpha_offset);
     if (res < 0)
         return res;
 
-- 
2.22.0