[FFmpeg-cvslog] avformat/oggparseogm: Check lb against psize

[Michael Niedermayer]

ffmpeg | branch: release/3.3 | Michael Niedermayer <michael at niedermayer.cc> | Fri Mar  9 01:05:20 2018 +0100| [e61cdbe27167434b87ff814769b54178c5a3d2a6] | committer: Michael Niedermayer

avformat/oggparseogm: Check lb against psize

No testcase, this was found during code review

Found-by: Matt Wolenetz <wolenetz at google.com>
Reviewed-by: Matt Wolenetz <wolenetz at google.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 3e7c847aaf5a298b62afae12b4ecfb8e12385998)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e61cdbe27167434b87ff814769b54178c5a3d2a6
---

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

diff --git a/libavformat/oggparseogm.c b/libavformat/oggparseogm.c
index 4d09d174b8..03499486f7 100644
--- a/libavformat/oggparseogm.c
+++ b/libavformat/oggparseogm.c
@@ -177,6 +177,9 @@ ogm_packet(AVFormatContext *s, int idx)
         os->pflags |= AV_PKT_FLAG_KEY;
 
     lb = ((*p & 2) << 1) | ((*p >> 6) & 3);
+    if (os->psize < lb + 1)
+        return AVERROR_INVALIDDATA;
+
     os->pstart += lb + 1;
     os->psize -= lb + 1;