[FFmpeg-devel] [PATCH 1/2] oavformat/avidec_ Check offset in odml

Michael Niedermayer michael at niedermayer.cc
Sun Sep 19 23:35:35 EEST 2021


Fixes: signed integer overflow: 9223372036854775807 + 8 cannot be represented in type 'long'
Fixes: 38787/clusterfuzz-testcase-minimized-ffmpeg_dem_AVI_fuzzer-4859845799444480

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 3eb5d4dff5f..1e8efc13060 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -244,7 +244,7 @@ static int read_odml_index(AVFormatContext *s, int64_t frame_num)
             avio_rl32(pb);       /* size */
             duration = avio_rl32(pb);
 
-            if (avio_feof(pb))
+            if (avio_feof(pb) || offset > INT64_MAX - 8)
                 return AVERROR_INVALIDDATA;
 
             pos = avio_tell(pb);
-- 
2.17.1



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