[FFmpeg-devel] [PATCH 3/4] avcodec/smacker: Fix integer overflow in signed int multiply in SMK_BLK_FILL

Michael Niedermayer michael at niedermayer.cc
Fri Sep 6 13:47:46 EEST 2019


Fixes: signed integer overflow: 238 * 16843009 cannot be represented in type 'int'
Fixes: 16958/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SMACKER_fuzzer-5193905355620352

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/smacker.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/smacker.c b/libavcodec/smacker.c
index c45137b7d5..a2950c455b 100644
--- a/libavcodec/smacker.c
+++ b/libavcodec/smacker.c
@@ -543,7 +543,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
             while(run-- && blk < blocks){
                 uint32_t col;
                 out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
-                col = mode * 0x01010101;
+                col = mode * 0x01010101U;
                 for(i = 0; i < 4; i++) {
                     *((uint32_t*)out) = col;
                     out += stride;
-- 
2.23.0



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