[FFmpeg-cvslog] avcodec/smc: Check input packet size

[Michael Niedermayer]

ffmpeg | branch: release/3.0 | Michael Niedermayer <michael at niedermayer.cc> | Fri Feb 23 03:40:02 2018 +0100| [789a12b140ba2426a1c9bb9ce31a7a4f50d0216a] | committer: Michael Niedermayer

avcodec/smc: Check input packet size

Fixes: Timeout
Fixes: 6261/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SMC_fuzzer-5811309653262336

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 0293663483ab5dbfff23602a62800d84e021b33c)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=789a12b140ba2426a1c9bb9ce31a7a4f50d0216a
---

 libavcodec/smc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/smc.c b/libavcodec/smc.c
index 18174fa57e..66de691e2c 100644
--- a/libavcodec/smc.c
+++ b/libavcodec/smc.c
@@ -437,6 +437,10 @@ static int smc_decode_frame(AVCodecContext *avctx,
     SmcContext *s = avctx->priv_data;
     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
     int ret;
+    int total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
+
+    if (total_blocks / 1024 > avpkt->size)
+        return AVERROR_INVALIDDATA;
 
     bytestream2_init(&s->gb, buf, buf_size);