From: Aleksa Sarai <cyphar@cyphar.com>
To: Jeff Layton <jlayton@kernel.org>,
"J. Bruce Fields" <bfields@fieldses.org>,
Al Viro <viro@zeniv.linux.org.uk>, Arnd Bergmann <arnd@arndb.de>,
Shuah Khan <shuah@kernel.org>
Cc: David Howells <dhowells@redhat.com>,
Andy Lutomirski <luto@kernel.org>,
Christian Brauner <christian@brauner.io>,
Eric Biederman <ebiederm@xmission.com>,
Aleksa Sarai <cyphar@cyphar.com>, Tycho Andersen <tycho@tycho.ws>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org,
dev@opencontainers.org, containers@lists.linux-foundation.org
Subject: Re: [PATCH 1/3] namei: implement O_BENEATH-style AT_* flags
Date: Sun, 30 Sep 2018 14:38:23 +1000 [thread overview]
Message-ID: <20180930043823.2pgzrtgcziaou7ov@ryuk> (raw)
In-Reply-To: <20180929103453.12025-2-cyphar@cyphar.com>
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On 2018-09-29, Aleksa Sarai <cyphar@cyphar.com> wrote:
> * AT_XDEV: Disallow mount-point crossing (both *down* into one, or *up*
> from one). The primary "scoping" use is to blocking resolution that
> crosses a bind-mount, which has a similar property to a symlink (in
> the way that it allows for escape from the starting-point). Since it
> is not possible to differentiate bind-mounts However since
> bind-mounting requires privileges (in ways symlinks don't) this has
> been split from LOOKUP_BENEATH. The naming is based on "find -xdev"
> (though find(1) doesn't walk upwards, the semantics seem obvious).
I've just noticed that the mountpoint-crossing code for AT_XDEV doesn't
detect things like:
% ln -s / /tmp/jumpup
% vfs_helper -o open -F xdev -d /tmp jumpup
/
I will fix that in v2.
--
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>
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next prev parent reply other threads:[~2018-09-30 4:38 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-29 10:34 [PATCH 0/3] namei: implement various scoping AT_* flags Aleksa Sarai
2018-09-29 10:34 ` [PATCH 1/3] namei: implement O_BENEATH-style " Aleksa Sarai
2018-09-29 14:48 ` Christian Brauner
2018-09-29 15:34 ` Aleksa Sarai
2018-09-30 4:38 ` Aleksa Sarai [this message]
2018-10-01 12:28 ` Jann Horn
2018-10-01 13:00 ` Christian Brauner
2018-10-01 16:04 ` Aleksa Sarai
2018-10-04 17:20 ` Christian Brauner
2018-09-29 13:15 ` [PATCH 2/3] namei: implement AT_THIS_ROOT chroot-like path resolution Aleksa Sarai
2018-09-29 13:15 ` [PATCH 3/3] selftests: vfs: add AT_* path resolution tests Aleksa Sarai
2018-09-29 16:35 ` [PATCH 2/3] namei: implement AT_THIS_ROOT chroot-like path resolution Jann Horn
2018-09-29 17:25 ` Andy Lutomirski
2018-10-01 9:46 ` Aleksa Sarai
2018-10-01 5:44 ` Aleksa Sarai
2018-10-01 10:13 ` Jann Horn
2018-10-01 16:18 ` Aleksa Sarai
2018-10-04 17:27 ` Christian Brauner
2018-10-01 10:42 ` Christian Brauner
2018-10-01 11:29 ` Jann Horn
2018-10-01 12:35 ` Christian Brauner
2018-10-01 13:55 ` Bruce Fields
2018-10-01 14:28 ` Andy Lutomirski
2018-10-02 7:32 ` Aleksa Sarai
2018-10-03 22:09 ` Andy Lutomirski
2018-10-06 20:56 ` Florian Weimer
2018-10-06 21:49 ` Christian Brauner
2018-10-01 14:00 ` Christian Brauner
2018-10-04 16:26 ` Aleksa Sarai
2018-10-04 17:31 ` Christian Brauner
2018-10-04 18:26 ` Jann Horn
2018-10-05 15:07 ` Aleksa Sarai
2018-10-05 15:55 ` Jann Horn
2018-10-06 2:10 ` Aleksa Sarai
2018-10-08 10:50 ` Jann Horn
2018-09-29 14:25 ` [PATCH 0/3] namei: implement various scoping AT_* flags Andy Lutomirski
2018-09-29 15:45 ` Aleksa Sarai
2018-09-29 16:34 ` Andy Lutomirski
2018-09-29 19:44 ` Matthew Wilcox
2018-09-29 14:38 ` Christian Brauner
2018-09-30 4:44 ` Aleksa Sarai
2018-09-30 13:54 ` Alban Crequy
2018-09-30 14:02 ` Christian Brauner
2018-09-30 19:45 ` Mickaël Salaün
2018-09-30 21:46 ` Jann Horn
2018-09-30 22:37 ` Mickaël Salaün
2018-10-01 20:14 ` James Morris
2018-10-01 4:08 ` Dave Chinner
2018-10-01 5:47 ` Aleksa Sarai
2018-10-01 6:14 ` Dave Chinner
2018-10-01 13:28 ` David Laight
2018-10-01 16:15 ` Aleksa Sarai
2018-10-03 13:21 ` David Laight
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