[FFmpeg-devel] [PATCH 2/6] avcodec/dxtory: Fix negative shift in dxtory_decode_v1_410()

Michael Niedermayer michael at niedermayer.cc
Sat Sep 26 01:26:34 EEST 2020


Fixes: left shift of negative value -256
Fixes: 25460/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DXTORY_fuzzer-5073252341514240

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/dxtory.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/libavcodec/dxtory.c b/libavcodec/dxtory.c
index 157e4b3ed2..a82532c467 100644
--- a/libavcodec/dxtory.c
+++ b/libavcodec/dxtory.c
@@ -177,10 +177,10 @@ static int dxtory_decode_v1_410(AVCodecContext *avctx, AVFrame *pic,
             V[huvborder] = src[1] + 0x80;
             src += 2;
         }
-        Y1 += pic->linesize[0] << 2;
-        Y2 += pic->linesize[0] << 2;
-        Y3 += pic->linesize[0] << 2;
-        Y4 += pic->linesize[0] << 2;
+        Y1 += pic->linesize[0] * 4;
+        Y2 += pic->linesize[0] * 4;
+        Y3 += pic->linesize[0] * 4;
+        Y4 += pic->linesize[0] * 4;
         U  += pic->linesize[1];
         V  += pic->linesize[2];
     }
-- 
2.17.1



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