[FFmpeg-cvslog] h264: reset ref count if decoding the slice header fails

[Anton Khirnov]

ffmpeg | branch: release/0.10 | Anton Khirnov <anton at khirnov.net> | Thu Nov 28 10:54:35 2013 +0100| [35ba079fbf281a066f3ac1e1271f3caa402dcd74] | committer: Reinhard Tartler

h264: reset ref count if decoding the slice header fails

Otherwise the ER code might try to use some already freed references.

Fixes possible access to freed memory.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=35ba079fbf281a066f3ac1e1271f3caa402dcd74
---

 libavcodec/h264.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index e88bb93..1c2f23a 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -4118,9 +4118,10 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
             context_count = 0;
         }
 
-        if (err < 0)
+        if (err < 0) {
             av_log(h->s.avctx, AV_LOG_ERROR, "decode_slice_header error\n");
-        else if(err == 1) {
+            h->ref_count[0] = h->ref_count[1] = h->list_count = 0;
+        } else if (err == 1) {
             /* Slice could not be decoded in parallel mode, copy down
              * NAL unit stuff to context 0 and restart. Note that
              * rbsp_buffer is not transferred, but since we no longer