File ffmpeg-CVE-2018-13305.patch of Package ffmpeg.27460
diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c
index f9f26f7..3d89207 100644
--- a/libavcodec/vc1_block.c
+++ b/libavcodec/vc1_block.c
@@ -188,7 +188,7 @@ static void vc1_put_signed_blocks_clamped(VC1Context *v)
mquant = v->altpq; \
if ((edges&8) && s->mb_y == (s->mb_height - 1)) \
mquant = v->altpq; \
- if (!mquant || mquant > 31) { \
+ if (!mquant || mquant > 31 || mquant < -31) { \
av_log(v->s.avctx, AV_LOG_ERROR, \
"Overriding invalid mquant %d\n", mquant); \
mquant = 1; \