[FFmpeg-devel] [PATCH 1/2] avformat/wtvdec: Check len in parse_chunks() to avoid overflow

Michael Niedermayer michael at niedermayer.cc
Mon Feb 8 15:29:01 EET 2021


Fixes: signed integer overflow: 2147483647 + 7 cannot be represented in type 'int'
Fixes: 30084/clusterfuzz-testcase-minimized-ffmpeg_dem_WTV_fuzzer-6192261941559296

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

diff --git a/libavformat/wtvdec.c b/libavformat/wtvdec.c
index 6c41e3c1a3..7def9d2348 100644
--- a/libavformat/wtvdec.c
+++ b/libavformat/wtvdec.c
@@ -794,7 +794,7 @@ static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_p
 
         ff_get_guid(pb, &g);
         len = avio_rl32(pb);
-        if (len < 32) {
+        if (len < 32 || len > INT_MAX - 7) {
             int ret;
             if (avio_feof(pb))
                 return AVERROR_EOF;
-- 
2.17.1



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