gst-ffmpeg: qdm2: check array index before use, fix out of array
 accesses

Upstream-Status: Backport 

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
 libavcodec/qdm2.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/libavcodec/qdm2.c b/libavcodec/qdm2.c
index 4cf4b2f..1dfb8d5 100644
--- a/gst-libs/ext/libav/libavcodec/qdm2.c
+++ b/gst-libs/ext/libav/libavcodec/qdm2.c
@@ -1257,6 +1257,11 @@ static void qdm2_decode_super_block (QDM2Context *q)
     for (i = 0; packet_bytes > 0; i++) {
         int j;
 
+        if (i>=FF_ARRAY_ELEMS(q->sub_packet_list_A)) {
+            SAMPLES_NEEDED_2("too many packet bytes");
+            return;
+        }
+
         q->sub_packet_list_A[i].next = NULL;
 
         if (i > 0) {
-- 
1.7.5.4