[FFmpeg-devel] [PATCH 4/4] avformat/wtvdec: Check for EOF before seeking back in parse_media_type()

Michael Niedermayer michael at niedermayer.cc
Sun Aug 1 22:30:31 EEST 2021


Fixes: Infinite loop
Fixes: 36311/clusterfuzz-testcase-minimized-ffmpeg_dem_WTV_fuzzer-4889181296918528

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, 2 insertions(+)

diff --git a/libavformat/wtvdec.c b/libavformat/wtvdec.c
index a549681322..191da2718b 100644
--- a/libavformat/wtvdec.c
+++ b/libavformat/wtvdec.c
@@ -652,6 +652,8 @@ static AVStream * parse_media_type(AVFormatContext *s, AVStream *st, int sid,
         avio_skip(pb, size - 32);
         ff_get_guid(pb, &actual_subtype);
         ff_get_guid(pb, &actual_formattype);
+        if (avio_feof(pb))
+            return NULL;
         avio_seek(pb, -size, SEEK_CUR);
 
         st = parse_media_type(s, st, sid, mediatype, actual_subtype, actual_formattype, size - 32);
-- 
2.17.1



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