[FFmpeg-devel] [PATCH] lavu/imgutils: add consistency check to av_image_copy_plane()

[Stefano Sabatini]

Add assertions and abort in case of invalid |dst_linesize| < bytewidth or
|src_linesize| < bytewidth.

Avoid to silently corrupt memory.

TODO: bump micro
---
 libavutil/imgutils.c |    3 +++
 libavutil/imgutils.h |    3 +++
 2 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/libavutil/imgutils.c b/libavutil/imgutils.c
index a3d4087..20df7b1 100644
--- a/libavutil/imgutils.c
+++ b/libavutil/imgutils.c
@@ -21,6 +21,7 @@
  * misc image utilities
  */
 
+#include "avassert.h"
 #include "common.h"
 #include "imgutils.h"
 #include "internal.h"
@@ -235,6 +236,8 @@ void av_image_copy_plane(uint8_t       *dst, int dst_linesize,
                          const uint8_t *src, int src_linesize,
                          int bytewidth, int height)
 {
+    av_assert0(abs(src_linesize) >= bytewidth);
+    av_assert0(abs(dst_linesize) >= bytewidth);
     if (!dst || !src)
         return;
     for (;height > 0; height--) {
diff --git a/libavutil/imgutils.h b/libavutil/imgutils.h
index 3b1904b..1434dbd 100644
--- a/libavutil/imgutils.h
+++ b/libavutil/imgutils.h
@@ -99,6 +99,9 @@ int av_image_alloc(uint8_t *pointers[4], int linesizes[4],
  * The first byte of each successive line is separated by *_linesize
  * bytes.
  *
+ * bytewidth must be contained by both absolute values of dst_linesize
+ * and src_linesize, otherwise the function behavior is undefined.
+ *
  * @param dst_linesize linesize for the image plane in dst
  * @param src_linesize linesize for the image plane in src
  */
-- 
1.7.5.4