[FFmpeg-cvslog] avcodec/vqcdec: Check width & 15

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Nov 23 21:27:13 2022 +0100| [a9d15d43eb0f976b982bf2ad6ec1d8ac084c7ded] | committer: Michael Niedermayer

avcodec/vqcdec: Check width & 15

Various parts of the code assume that width can be divided by various powers of 2
without rounding

Fixes: out of array access
Fixes: 53623/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VQC_fuzzer-6209269924233216

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a9d15d43eb0f976b982bf2ad6ec1d8ac084c7ded
---

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

diff --git a/libavcodec/vqcdec.c b/libavcodec/vqcdec.c
index 18cd99462e..c3bce87974 100644
--- a/libavcodec/vqcdec.c
+++ b/libavcodec/vqcdec.c
@@ -71,6 +71,9 @@ static av_cold int vqc_decode_init(AVCodecContext * avctx)
     static AVOnce init_static_once = AV_ONCE_INIT;
     VqcContext *s = avctx->priv_data;
 
+    if (avctx->width & 15)
+        return AVERROR_PATCHWELCOME;
+
     s->vectors = av_malloc((avctx->width * avctx->height * 3) / 2);
     if (!s->vectors)
         return AVERROR(ENOMEM);