[FFmpeg-devel] [PATCH 09/12] avformat/avidec: Use 64bit in get_duration()

Michael Niedermayer michael at niedermayer.cc
Sun Jan 31 21:18:15 EET 2021


Fixes: signed integer overflow: 2147483424 + 8224 cannot be represented in type 'int'
Fixes: 29619/clusterfuzz-testcase-minimized-ffmpeg_dem_AVI_fuzzer-5191424373030912

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/avidec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index 79000f3e81..547eb63b1b 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -135,7 +135,7 @@ static inline int get_duration(AVIStream *ast, int len)
     if (ast->sample_size)
         return len;
     else if (ast->dshow_block_align)
-        return (len + ast->dshow_block_align - 1) / ast->dshow_block_align;
+        return (len + (int64_t)ast->dshow_block_align - 1) / ast->dshow_block_align;
     else
         return 1;
 }
-- 
2.17.1



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