commit 96c6b3a11c47555ad269404b62078124b7bb6ebf
author Michael Niedermayer <michaelni@gmx.at> Fri Mar 02 15:58:14 2012 +0100
committer Michael Niedermayer <michaelni@gmx.at> Fri May 11 22:39:31 2012 +0200
tree d13f323f2bb1a932f93b9989f190b28621fb8656
parent 5e3cd42b6d0760d35fb0dec62ad13f09dee94448

h261: check mtype.

Fixes out of array read

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit ec3cd74f2dab8e3e8234ccb994132b23d3098585)

libavcodec/h261dec.c

diff --git a/libavcodec/h261dec.c b/libavcodec/h261dec.c
index 7054286..aa1be6f 100644
--- a/libavcodec/h261dec.c
+++ b/libavcodec/h261dec.c
@@ -285,6 +285,10 @@
 
     // Read mtype
     h->mtype = get_vlc2(&s->gb, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2);
+    if (h->mtype < 0) {
+        av_log(s->avctx, AV_LOG_ERROR, "illegal mtype %d\n", h->mtype);
+        return SLICE_ERROR;
+    }
     h->mtype = h261_mtype_map[h->mtype];
 
     // Read mquant