h264: reset data_partitioning if decoding the slice header for NAL_DPA fails
authorAnton Khirnov <anton@khirnov.net>
Thu, 28 Nov 2013 09:54:35 +0000 (10:54 +0100)
committerSean McGovern <gseanmcg@gmail.com>
Mon, 14 Apr 2014 20:55:38 +0000 (16:55 -0400)
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@libav.org
(cherry picked from commit 58312b2472d3a44d7458865c459d59ef2e02bf1a)

libavcodec/h264.c

index 20fa82c..7acc5a7 100644 (file)
@@ -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;