[FFmpeg-devel] [PATCH 3/4] avformat/mov: Fix incorrect overflow detection in mov_read_sidx()

Michael Niedermayer michael at niedermayer.cc
Wed Apr 28 18:06:35 EEST 2021


Fixes: signed integer overflow: 9223372036854775807 + 1442840321 cannot be represented in type 'long'
Fixes: 33670/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6644379491106816

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

diff --git a/libavformat/mov.c b/libavformat/mov.c
index ca8f06c4cd..0f94abd040 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -5080,7 +5080,7 @@ static int mov_read_sidx(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         if (frag_stream_info)
             frag_stream_info->sidx_pts = timestamp;
 
-        if (av_sat_add64(offset, size) != offset + size ||
+        if (av_sat_add64(offset, size) != offset + (uint64_t)size ||
             av_sat_add64(pts, duration) != pts + (uint64_t)duration
         )
             return AVERROR_INVALIDDATA;
-- 
2.17.1



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