[FFmpeg-cvslog] avcodec/vc1dec: Clear block_index in vc1_decode_reset()

[Michael Niedermayer]

ffmpeg | branch: release/4.3 | Michael Niedermayer <michael at niedermayer.cc> | Sun Dec  1 23:30:55 2024 +0100| [719ebc4adb56efdd00edefa9bf7c0719dde717ba] | committer: Michael Niedermayer

avcodec/vc1dec: Clear block_index in vc1_decode_reset()

Fixes: 377965565/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1_fuzzer-4504434689769472
Fixes: out of array access

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 251de1791e645f16e80b09d82999d4a5e24b1ad1)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=719ebc4adb56efdd00edefa9bf7c0719dde717ba
---

 libavcodec/vc1dec.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c
index a7f46a2246..492dccc1e1 100644
--- a/libavcodec/vc1dec.c
+++ b/libavcodec/vc1dec.c
@@ -608,6 +608,7 @@ av_cold int ff_vc1_decode_end(AVCodecContext *avctx)
     av_freep(&v->hrd_rate);
     av_freep(&v->hrd_buffer);
     ff_mpv_common_end(&v->s);
+    memset(v->s.block_index, 0, sizeof(v->s.block_index));
     av_freep(&v->mv_type_mb_plane);
     av_freep(&v->direct_mb_plane);
     av_freep(&v->forward_mb_plane);