[FFmpeg-cvslog] h264: prevent two matching fields from being both a short/ long ref combination

[Anton Khirnov]

ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Thu Nov 28 10:54:35 2013 +0100| [98cc9efc5f6b4dc847ed3b9b60b1c3bcd14e6791] | committer: Anton Khirnov

h264: prevent two matching fields from being both a short/long ref combination

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=98cc9efc5f6b4dc847ed3b9b60b1c3bcd14e6791
---

 libavcodec/h264_refs.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
index bba77d1..88aaac7 100644
--- a/libavcodec/h264_refs.c
+++ b/libavcodec/h264_refs.c
@@ -621,6 +621,8 @@ int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count)
                      * Report the problem and keep the pair where it is,
                      * and mark this field valid.
                      */
+            if (h->short_ref[0] == h->cur_pic_ptr)
+                remove_short_at_index(h, 0);
 
             if (h->long_ref[mmco[i].long_arg] != h->cur_pic_ptr) {
                 remove_long(h, mmco[i].long_arg, 0);