From c34ec56ea8f2e7b17e88f49cdc6a66a36702461c Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Date: Thu, 26 Feb 2015 21:38:50 +0100
Subject: [PATCH] avformat/bit: check that pkt->size is 10 in write_packet

Ohter packet sizes are not supported by this muxer.

This avoids a null pointer dereference of pkt->data.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit eeda2c3de8a8484d9e7d1e47ac836bec850b31fc)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
 libavformat/bit.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavformat/bit.c b/libavformat/bit.c
index 9f6ea4a415..daad7ccc7d 100644
--- a/libavformat/bit.c
+++ b/libavformat/bit.c
@@ -133,6 +133,9 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)
     GetBitContext gb;
     int i;
 
+    if (pkt->size != 10)
+        return AVERROR(EINVAL);
+
     avio_wl16(pb, SYNC_WORD);
     avio_wl16(pb, 8 * 10);