[FFmpeg-cvslog] avcodec/smc: Check side data size before use

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Oct 30 15:12:12 2016 +0100| [140f48b90fbe32a88423aad473bccc72c3bb450e] | committer: Michael Niedermayer

avcodec/smc:  Check side data size before use

Fixes out of array read

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=140f48b90fbe32a88423aad473bccc72c3bb450e
---

 libavcodec/smc.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/libavcodec/smc.c b/libavcodec/smc.c
index 69d78ad..8952421 100644
--- a/libavcodec/smc.c
+++ b/libavcodec/smc.c
@@ -431,7 +431,8 @@ static int smc_decode_frame(AVCodecContext *avctx,
     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
     SmcContext *s = avctx->priv_data;
-    const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
+    int pal_size;
+    const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
     int ret;
 
     bytestream2_init(&s->gb, buf, buf_size);
@@ -439,9 +440,11 @@ static int smc_decode_frame(AVCodecContext *avctx,
     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
         return ret;
 
-    if (pal) {
+    if (pal && pal_size == AVPALETTE_SIZE) {
         s->frame->palette_has_changed = 1;
         memcpy(s->pal, pal, AVPALETTE_SIZE);
+    } else if (pal) {
+        av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", pal_size);
     }
 
     smc_decode_stream(s);