[FFmpeg-cvslog] avformat/rmdec: sanity check coded_framesize

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Aug 16 18:05:34 2020 +0200| [aee8477c6ba20469ebe531448d31c642717b5f48] | committer: Michael Niedermayer

avformat/rmdec: sanity check coded_framesize

Fixes: signed integer overflow: -14671840 * 8224 cannot be represented in type 'int'
Fixes: 24793/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5101884323659776

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=aee8477c6ba20469ebe531448d31c642717b5f48
---

 libavformat/rmdec.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index 72b8dba741..03ddf29226 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -165,7 +165,11 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
         avio_rb16(pb); /* version2 */
         avio_rb32(pb); /* header size */
         flavor= avio_rb16(pb); /* add codec info / flavor */
-        ast->coded_framesize = coded_framesize = avio_rb32(pb); /* coded frame size */
+        coded_framesize = avio_rb32(pb); /* coded frame size */
+        if (coded_framesize < 0)
+            return AVERROR_INVALIDDATA;
+        ast->coded_framesize = coded_framesize;
+
         avio_rb32(pb); /* ??? */
         bytes_per_minute = avio_rb32(pb);
         if (version == 4) {