linux-kernel - Re: [patch 7/9] unprivileged mounts: allow unprivileged fuse mounts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <E1JCN9I-0004DB-DF@pomaz-ex.szeredi.hu>
Date:	Tue, 08 Jan 2008 23:42:20 +0100
From:	Miklos Szeredi <miklos@...redi.hu>
To:	pavel@....cz
CC:	akpm@...ux-foundation.org, hch@...radead.org, serue@...ibm.com,
	viro@....linux.org.uk, ebiederm@...ssion.com, kzak@...hat.com,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	containers@...ts.osdl.org, util-linux-ng@...r.kernel.org
Subject: Re: [patch 7/9] unprivileged mounts: allow unprivileged fuse mounts

> On Tue 2008-01-08 12:35:09, Miklos Szeredi wrote:
> > From: Miklos Szeredi <mszeredi@...e.cz>
> > 
> > Use FS_SAFE for "fuse" fs type, but not for "fuseblk".
> > 
> > FUSE was designed from the beginning to be safe for unprivileged users.  This
> > has also been verified in practice over many years.  In addition unprivileged
> 
> Eh? So 'kill -9 no longer works' and 'suspend no longer works' is not
> considered important enough to even mention?

No.  Because in practice they don't seem to matter.  Also because
there's no way in which fuse could be done differently to address
these issues.

The 'kill -9' thing is basically due to VFS level locking not being
interruptible.  It could be changed, but I'm not sure it's worth it.

For the suspend issue, there are also no easy solutions.

> 'updatedb no longer works' is not a problem?

I haven't seen any problems with updatedb, and haven't had any bug
reports about it either.

> Are you ready to offer shell account for bugtraq people to see how
> long it survives?

Bugtraq people are free to install fuse on their machines and take it
apart.

AFAIR there were two security vulnerabilities in fuse's history, one
of them an information leak in the kernel module, and the other one an
mtab corruption issue in the fusermount utility.  I don't think this
is such a bad track record.

Miklos
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/