[FFmpeg-cvslog] avformat/iff: Check size before skip

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Nov 14 20:59:01 2020 +0100| [8b50e8bc2975fad85e0713e05940ee9ecb5e8a18] | committer: Michael Niedermayer

avformat/iff: Check size before skip

Fixes: Infinite loop
Fixes: 27292/clusterfuzz-testcase-minimized-ffmpeg_dem_IFF_fuzzer-5731168991051776

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8b50e8bc2975fad85e0713e05940ee9ecb5e8a18
---

 libavformat/iff.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavformat/iff.c b/libavformat/iff.c
index a70184f105..f017684620 100644
--- a/libavformat/iff.c
+++ b/libavformat/iff.c
@@ -259,6 +259,9 @@ static int parse_dsd_prop(AVFormatContext *s, AVStream *st, uint64_t eof)
         uint64_t size     = avio_rb64(pb);
         uint64_t orig_pos = avio_tell(pb);
 
+        if (size >= INT64_MAX)
+            return AVERROR_INVALIDDATA;
+
         switch(tag) {
         case MKTAG('A','B','S','S'):
             if (size < 8)