[FFmpeg-cvslog] h264: reset data_partitioning if decoding the slice header for NAL_DPA fails

[Anton Khirnov]

ffmpeg | branch: release/1.1 | Anton Khirnov <anton at khirnov.net> | Thu Nov 28 10:54:35 2013 +0100| [1147d39bca135df8673031d16989ba486a52172a] | committer: Sean McGovern

h264: reset data_partitioning if decoding the slice header for NAL_DPA fails

If it was set before then we can end up trying to decode a slice without
a valid slice header, which can lead to invalid memory access.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org
(cherry picked from commit 58312b2472d3a44d7458865c459d59ef2e02bf1a)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1147d39bca135df8673031d16989ba486a52172a
---

 libavcodec/h264.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 20fa82c..7acc5a7 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -4061,8 +4061,13 @@ again:
                 hx->intra_gb_ptr =
                 hx->inter_gb_ptr = NULL;
 
-                if ((err = decode_slice_header(hx, h)) < 0)
+                if ((err = decode_slice_header(hx, h)) < 0) {
+                    /* make sure data_partitioning is cleared if it was set
+                     * before, so we don't try decoding a slice without a valid
+                     * slice header later */
+                    s->data_partitioning = 0;
                     break;
+                }
 
                 hx->s.data_partitioning = 1;
                 break;