[vlc-commits] mkv: Fix potential buffer overflow

[Hugo Beauzée-Luyssen]

vlc | branch: master | Hugo Beauzée-Luyssen <hugo at beauzee.fr> | Fri May  3 22:42:34 2019 +0200| [af75fb6f24d74e51dbddeca5c6692404e7b25307] | committer: Hugo Beauzée-Luyssen

mkv: Fix potential buffer overflow

https://hackerone.com/reports/503218

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=af75fb6f24d74e51dbddeca5c6692404e7b25307
---

 modules/demux/mkv/matroska_segment_parse.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/modules/demux/mkv/matroska_segment_parse.cpp b/modules/demux/mkv/matroska_segment_parse.cpp
index ae888251a8..5a9bc732f5 100644
--- a/modules/demux/mkv/matroska_segment_parse.cpp
+++ b/modules/demux/mkv/matroska_segment_parse.cpp
@@ -1838,6 +1838,8 @@ bool matroska_segment_c::TrackInit( mkv_track_t * p_tk )
                 p_tk->fmt.audio.i_bitspersample = GetWLE( &p_wf->wBitsPerSample );
 
                 p_tk->fmt.i_extra            = GetWLE( &p_wf->cbSize );
+                if ( (size_t)p_tk->fmt.i_extra > p_tk->i_extra_data - sizeof( WAVEFORMATEX ) )
+                    p_tk->fmt.i_extra = 0;
                 if( p_tk->fmt.i_extra != 0 )
                 {
                     p_tk->fmt.p_extra = xmalloc( p_tk->fmt.i_extra );