[FFmpeg-devel] [PATCH] avcodec/videodsp_template: Fix overflow of addition

[Michael Niedermayer]

Fixes: addition of unsigned offset to 0x7f56fc26a9b6 overflowed to 0x7f56fc26a8be*
Fixes: clusterfuzz-testcase-minimized-mediasource_MP4_AVC1_pipeline_integration_fuzzer-4917949056679936

Reported-by: Matt Wolenetz <wolenetz at google.com>
Reviewed-by: Matt Wolenetz <wolenetz at google.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/videodsp_template.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/videodsp_template.c b/libavcodec/videodsp_template.c
index 94c1b7188d..eae2f1d51b 100644
--- a/libavcodec/videodsp_template.c
+++ b/libavcodec/videodsp_template.c
@@ -44,7 +44,7 @@ void FUNC(ff_emulated_edge_mc)(uint8_t *buf, const uint8_t *src,
         src_y = 1 - block_h;
     }
     if (src_x >= w) {
-        src  += (w - 1 - src_x) * sizeof(pixel);
+        src  -= (1 + src_x - w) * sizeof(pixel);
         src_x = w - 1;
     } else if (src_x <= -block_w) {
         src  += (1 - block_w - src_x) * sizeof(pixel);
-- 
2.21.0