From: Miklos Szeredi <miklos@szeredi.hu>
To: Seth Forshee <seth.forshee@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
"Serge H. Hallyn" <serge.hallyn@ubuntu.com>,
Andy Lutomirski <luto@amacapital.net>,
Michael j Theall <mtheall@us.ibm.com>,
fuse-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v5 2/4] fuse: Support fuse filesystems outside of init_user_ns
Date: Tue, 11 Nov 2014 15:04:54 +0100 [thread overview]
Message-ID: <20141111140454.GD333@tucsk> (raw)
In-Reply-To: <1414013060-137148-3-git-send-email-seth.forshee@canonical.com>
On Wed, Oct 22, 2014 at 04:24:18PM -0500, Seth Forshee wrote:
> Update fuse to translate uids and gids to/from the user namspace
> of the process servicing requests on /dev/fuse. Any ids which do
> not map into the namespace will result in errors. inodes will
> also be marked bad when unmappable ids are received from
> userspace.
Okay.
> Due to security concerns the namespace used should be fixed,
> otherwise a user might be able to gain elevated privileges or
> influence processes that the user would otherwise be unable to
> manipulate. Thus the namespace of the mounting process is used
> for all translations, and this namespace is required to be the
> same as the one in use when /dev/fuse was opened.
Maybe I'm being dense, but can someone give a concrete example of such an
attack?
That might also help me understand how exactly user/pid namespaces work...
Patch otherwise looks okay.
Thanks,
Miklos
next prev parent reply other threads:[~2014-11-11 14:04 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-22 21:24 [PATCH v5 0/4] fuse: Add support for mounts from pid/user namespaces Seth Forshee
2014-10-22 21:24 ` [PATCH v5 1/4] fuse: Add support for pid namespaces Seth Forshee
2014-11-11 13:27 ` Miklos Szeredi
2014-11-11 15:24 ` Seth Forshee
2014-11-11 15:39 ` Andy Lutomirski
2014-11-11 16:26 ` Seth Forshee
2014-11-12 12:07 ` Miklos Szeredi
2014-11-12 14:33 ` Seth Forshee
2014-10-22 21:24 ` [PATCH v5 2/4] fuse: Support fuse filesystems outside of init_user_ns Seth Forshee
2014-10-22 21:47 ` Andy Lutomirski
2014-11-11 14:04 ` Miklos Szeredi [this message]
2014-11-11 15:27 ` Seth Forshee
2014-11-11 15:37 ` Eric W. Biederman
2014-11-12 13:09 ` Miklos Szeredi
2014-11-12 16:22 ` Seth Forshee
2014-11-18 15:21 ` Seth Forshee
2014-11-18 17:09 ` Andy Lutomirski
2014-11-18 17:13 ` Seth Forshee
2014-11-18 17:19 ` Andy Lutomirski
2014-11-19 8:50 ` Miklos Szeredi
2014-11-19 10:38 ` Miklos Szeredi
2014-11-19 14:09 ` Serge E. Hallyn
2014-11-21 16:44 ` Seth Forshee
2014-11-21 17:19 ` Andy Lutomirski
2014-11-21 18:14 ` Eric W. Biederman
2014-11-21 18:25 ` Andy Lutomirski
2014-11-21 18:27 ` Seth Forshee
2014-11-21 18:38 ` Andy Lutomirski
2014-10-22 21:24 ` [PATCH v5 3/4] fuse: Restrict allow_other to the superblock's namespace or a descendant Seth Forshee
2014-10-22 21:48 ` Andy Lutomirski
2014-11-11 15:27 ` Miklos Szeredi
2014-11-11 15:37 ` Seth Forshee
2014-10-22 21:24 ` [PATCH v5 4/4] fuse: Allow user namespace mounts Seth Forshee
2014-10-22 21:51 ` Andy Lutomirski
2014-10-23 0:22 ` Seth Forshee
2014-10-23 2:19 ` Andy Lutomirski
2014-11-03 17:15 ` [PATCH v5 0/4] fuse: Add support for mounts from pid/user namespaces Seth Forshee
2014-11-03 17:17 ` Andy Lutomirski
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