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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Shea Levy <shea@shealevy.com>
Cc: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Setting FS_USERNS_MOUNT in btrfs_fs_type.fs_flags
Date: Wed, 17 Sep 2014 04:54:48 +0100	[thread overview]
Message-ID: <20140917035448.GZ7996@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20140917030500.GD6185@nixos.hsd1.nh.comcast.net>

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.

  reply	other threads:[~2014-09-17  3:54 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-17  3:05 Setting FS_USERNS_MOUNT in btrfs_fs_type.fs_flags Shea Levy
2014-09-17  3:54 ` Al Viro [this message]
2014-09-17 16:12   ` Zach Brown
2014-09-17 20:31     ` Shea Levy

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