[FFmpeg-cvslog] avformat/mpeg: Check an avio_read() for failure

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sun Aug  4 21:27:44 2024 +0200| [5ea7acb177288032a6bf90d4dcf2e69e80ef7e42] | committer: Michael Niedermayer

avformat/mpeg: Check an avio_read() for failure

Fixes: use-of-uninitialized-value
Fixes: 70849/clusterfuzz-testcase-minimized-ffmpeg_dem_MPEGPS_fuzzer-4684401009557504

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 66ee75d76ce56a3553a99d67e74b8a9970c18f5b)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5ea7acb177288032a6bf90d4dcf2e69e80ef7e42
---

 libavformat/mpeg.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index f0b1f1ac34..6b2c5a9be0 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -540,7 +540,9 @@ redo:
         static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
         unsigned char buf[8];
 
-        avio_read(s->pb, buf, 8);
+        ret = avio_read(s->pb, buf, 8);
+        if (ret != 8)
+            return AVERROR_INVALIDDATA;
         avio_seek(s->pb, -8, SEEK_CUR);
         if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
             codec_id = AV_CODEC_ID_CAVS;