[FFmpeg-cvslog] avformat/dvdvideodec: check the length of a NAV packet when reading titles

[Marth64]

ffmpeg | branch: release/7.1 | Marth64 <marth64 at proxyid.net> | Mon Oct  7 18:04:58 2024 -0500| [a61eb0c2c0d51567de5e8d3627bff9ba08020410] | committer: Marth64

avformat/dvdvideodec: check the length of a NAV packet when reading titles

Some discs present titles with bogus NAV packets. We apply this check
for menus and for title MPEG blocks, but we should also apply it
for NAV packets during title demuxing.

Signed-off-by: Marth64 <marth64 at proxyid.net>
(cherry picked from commit afc152f564fbeca4d2ff62195e3f0b6244e28cb3)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a61eb0c2c0d51567de5e8d3627bff9ba08020410
---

 libavformat/dvdvideodec.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libavformat/dvdvideodec.c b/libavformat/dvdvideodec.c
index 726c45601f..f7c7ba5a3b 100644
--- a/libavformat/dvdvideodec.c
+++ b/libavformat/dvdvideodec.c
@@ -740,6 +740,13 @@ static int dvdvideo_play_next_ps_block(AVFormatContext *s, DVDVideoPlaybackState
                     return AVERROR_EOF;
                 }
 
+                if (nav_len != DVDVIDEO_BLOCK_SIZE) {
+                    av_log(s, AV_LOG_ERROR, "Invalid NAV packet size (expected=%d actual=%d)\n",
+                                            DVDVIDEO_BLOCK_SIZE, nav_len);
+
+                    return AVERROR_INVALIDDATA;
+                }
+
                 e_pci = dvdnav_get_current_nav_pci(state->dvdnav);
                 e_dsi = dvdnav_get_current_nav_dsi(state->dvdnav);