From 2566ad98b01538ea589e5ee07b69fc566aadc348 Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Date: Thu, 24 Nov 2016 23:57:46 +0100
Subject: [PATCH] mss2: only use error correction for matching block counts
This fixes a heap-buffer-overflow in ff_er_frame_end when decoding mss2
with coded_width/coded_height larger than width/height.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
---
libavcodec/mss2.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/libavcodec/mss2.c b/libavcodec/mss2.c
index 1e24568128b..581865b0b13 100644
--- a/libavcodec/mss2.c
+++ b/libavcodec/mss2.c
@@ -422,7 +422,13 @@ static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
ff_vc1_decode_blocks(v);
- ff_er_frame_end(&s->er);
+ if (v->end_mb_x == s->mb_width && s->end_mb_y == s->mb_height) {
+ ff_er_frame_end(&s->er);
+ } else {
+ av_log(v->s.avctx, AV_LOG_WARNING,
+ "disabling error correction due to block count mismatch %dx%d != %dx%d\n",
+ v->end_mb_x, s->end_mb_y, s->mb_width, s->mb_height);
+ }
ff_mpv_frame_end(s);
--
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