From: Ben Hutchings <ben@decadent.org.uk>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: stable@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sasha.levin@oracle.com>,
Jiri Slaby <jirislaby@gmail.com>,
Willy Tarreau <willy@meta-x.org>, Li Zefan <lizefan@huawei.com>
Subject: Re: [PATCHES] Bind mount escape fixes (CVE-2015-2925)
Date: Sat, 03 Oct 2015 02:48:03 +0100 [thread overview]
Message-ID: <1443836883.2730.223.camel@decadent.org.uk> (raw)
In-Reply-To: <87vbaptg2s.fsf@x220.int.ebiederm.org>
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On Fri, 2015-10-02 at 11:01 -0500, Eric W. Biederman wrote:
[...]
> Having thought about this I definitely think we need this on older
> kernels. I am aware of at least one piece of software that predates
> 2.6.32 is vulnerable to this escape.
>
> The software in all innocence bind mounted a users /home directory into
> a root filesystem that was stored in the users /home directory. That
> is enough to allow the escape with a simple unprivileged rename.
>
> So since this is actually exploitable on real userspace software that
> predates 2.6.32 I think this fix needs to be backported, as it is not
> a theoretical issue.
Thanks for the explanation. I'll review and test the patches for
2.6.32 and 3.2 in a while.
Ben.
--
Ben Hutchings
compatible: Gracefully accepts erroneous data from any source
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next prev parent reply other threads:[~2015-10-03 1:48 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-01 16:15 [PATCHES] Bind mount escape fixes (CVE-2015-2925) Eric W. Biederman
2015-10-01 23:08 ` Willy Tarreau
2015-10-02 2:45 ` Ben Hutchings
2015-10-02 3:28 ` Eric W. Biederman
2015-10-02 16:01 ` Eric W. Biederman
2015-10-03 1:48 ` Ben Hutchings [this message]
2015-10-03 6:12 ` Willy Tarreau
2015-10-02 9:26 ` Jiri Slaby
2015-10-05 10:34 ` Luis Henriques
2015-10-08 1:08 ` Ben Hutchings
2015-10-08 5:11 ` Willy Tarreau
2015-10-18 0:01 ` Greg Kroah-Hartman
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