[vlc-devel] [PATCH] M3u & pls demux: Check the size of each file line to prevent flooding the playlist.
funman at videolan.org
Wed Apr 24 13:18:24 CEST 2013
Le 24/04/2013 13:09, Adrien Maglo a écrit :
> The exploit attached to the ticket #7361 shows that it is possible to
> freeze VLC with a corrupted playlist file containing very long lines.
> VLC indeed outputs to the logs a message giving the name of the media,
> which is extremely long. This is not a security issue but as logging is
> a costly operation, outputting this message takes a lot of time and
> freezes VLC.
> The attached patch proposes to set a maximum line length for the M3U and
> PLS playlist format. It therefore prevent the playlist from being
> flooded using these demux.
> -- MagSoft
> From a86408bef4c58408a3eee4c916babca373b21794 Mon Sep 17 00:00:00 2001
> From: Adrien Maglo <magsoft at videolan.org>
> Date: Wed, 24 Apr 2013 12:48:25 +0200
> Subject: [PATCH] M3u & pls demux: Check the size of each file line to prevent
> flooding the playlist.
> This commit fixes the ticket #7361.
> modules/demux/playlist/m3u.c | 8 ++++++++
> modules/demux/playlist/pls.c | 9 ++++++++-
> 2 files changed, 16 insertions(+), 1 deletion(-)
> diff --git a/modules/demux/playlist/m3u.c b/modules/demux/playlist/m3u.c
> index 8519488..2c8849d 100644
> --- a/modules/demux/playlist/m3u.c
> +++ b/modules/demux/playlist/m3u.c
> @@ -157,6 +157,10 @@ void Close_M3U( vlc_object_t *p_this )
> +/* Magic number. There is no official specification of the maximum line size
> + for the m3u playlist format. */
> +#define MAX_M3U_LINE_SIZE 1024
1024 seems too low.
PATH_MAX seems to be 4096 on linux, and browsers are said to accept up
to 2048 bytes long URLs according to some experiment which can be found
on Stack Overflow.
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