linux-kernel - Re: Setting FS_USERNS_MOUNT in btrfs_fs_type.fs

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]

Date:	Wed, 17 Sep 2014 04:54:48 +0100
From:	Al Viro <viro@...IV.linux.org.uk>
To:	Shea Levy <shea@...alevy.com>
Cc:	linux-btrfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: Setting FS_USERNS_MOUNT in btrfs_fs_type.fs_flags

On Tue, Sep 16, 2014 at 11:05:00PM -0400, Shea Levy wrote:
> Hi all,
> 
> What work would be required to mark btrfs_fs_type with FS_USERNS_MOUNT
> so that btrfs images can be mounted by unprivileged users within a user
> namespace (along with something like [1])? I'd like to be able to create
> disk images without having to start a VM (and --rootdir isn't flexible
> enough because I want to make subvolumes).

Er...  Which is to say, you have an audit of btrfs code making sure that
it can cope with arbitrary image hand-crafted by potential attacker?
Because without that FS_USERNS_MOUNT could open one hell of security hole;
things like user being able to execute an arbitrary code in kernel mode,
etc.
--
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/