[FFmpeg-cvslog] avcodec/utils: Align dimensions by at least their chroma sub-sampling factors.

[Michael Niedermayer]

ffmpeg | branch: release/2.2 | Michael Niedermayer <michaelni at gmx.at> | Wed Oct 29 14:15:29 2014 +0100| [16a4aef34574549316ba1a96a26edd1c9a4fb1e3] | committer: Michael Niedermayer

avcodec/utils: Align dimensions by at least their chroma sub-sampling factors.

Fixes: out of array accesses
Fixes: asan_heap-oob_112c6b3_13_012.avi
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit df74811cd53e45fcbbd3b77a1c42416816687c5c)

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=16a4aef34574549316ba1a96a26edd1c9a4fb1e3
---

 libavcodec/utils.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 8b6f942..8d24f0b 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -281,6 +281,12 @@ void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
     int i;
     int w_align = 1;
     int h_align = 1;
+    AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->pix_fmt);
+
+    if (desc) {
+        w_align = 1 << desc->log2_chroma_w;
+        h_align = 1 << desc->log2_chroma_h;
+    }
 
     switch (s->pix_fmt) {
     case AV_PIX_FMT_YUV420P:
@@ -407,8 +413,6 @@ void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
         }
         break;
     default:
-        w_align = 1;
-        h_align = 1;
         break;
     }