[FFmpeg-cvslog] avformat/iff: Check data_size

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Dec 11 00:49:23 2020 +0100| [001bc594d82f3df67a6e96c6ea022f4e39002385] | committer: Michael Niedermayer

avformat/iff: Check data_size

Fixes: infinite loop
Fixes: 27834/clusterfuzz-testcase-minimized-ffmpeg_dem_IFF_fuzzer-5694930919620608

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=001bc594d82f3df67a6e96c6ea022f4e39002385
---

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

diff --git a/libavformat/iff.c b/libavformat/iff.c
index f017684620..2dba121f6f 100644
--- a/libavformat/iff.c
+++ b/libavformat/iff.c
@@ -368,7 +368,7 @@ static int read_dst_frame(AVFormatContext *s, AVPacket *pkt)
         data_size = iff->is_64bit ? avio_rb64(pb) : avio_rb32(pb);
         data_pos = avio_tell(pb);
 
-        if (data_size < 1)
+        if (data_size < 1 || data_size >= INT64_MAX)
             return AVERROR_INVALIDDATA;
 
         switch (chunk_id) {