From: Mike Waychison <Michael.Waychison@Sun.COM>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
raven@themaw.net
Subject: Re: [PATCH 12/28] VFS: Remove (now bogus) check_mnt
Date: Mon, 25 Oct 2004 11:15:34 -0400 [thread overview]
Message-ID: <417D1896.4080901@sun.com> (raw)
In-Reply-To: <20041025150941.GA1682@infradead.org>
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Christoph Hellwig wrote:
> On Mon, Oct 25, 2004 at 10:44:33AM -0400, Mike Waychison wrote:
>
>>check_mnt used to be used to see if a mountpoint was actually grafted or not
>>to a namespace. This was done because we didn't support mountpoints being
>>attached to one another if they weren't associated with a namespace. We now
>>support this, so all check_mnt calls are bogus. The only exception is that
>>pivot_root still requires all participants to exist within the same
>>namespace.
>
>
> did you audit the namespace code that it doesn't allow attachign to other
> namespaces than the current?
>
So, I don't see how that is possible, other than through relative
resolution from a cwd in the other namespace. Arguably, you aren't
buying any security by denying the mountpoint if you already let other
processes in your namespace.
Auditting the original code, it appeared that doing such a thing was a
no-no only because the locking semantics of current->namespace->sem made
this difficult.
- --
Mike Waychison
Sun Microsystems, Inc.
1 (650) 352-5299 voice
1 (416) 202-8336 voice
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NOTICE: The opinions expressed in this email are held by me,
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next prev parent reply other threads:[~2004-10-25 15:15 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-25 14:38 [PATCH 0/28] Autofs NG Patchset 0.2 Mike Waychison
2004-10-25 14:39 ` [PATCH 1/28] VFS: Unexport umount_tree Mike Waychison
2004-10-25 14:39 ` [PATCH 2/28] VFS: mnt_fslink -> mnt_expire Mike Waychison
2004-10-25 14:40 ` [PATCH 3/28] VFS: Move expiry into vfs Mike Waychison
2004-10-25 14:40 ` [PATCH 4/28] VFS: Stat shouldn't stop expire Mike Waychison
2004-10-25 14:41 ` [PATCH 5/28] VFS: Make expiry timeout configurable Mike Waychison
2004-10-25 14:41 ` [PATCH 6/28] VFS: Make expiry recursive Mike Waychison
2004-10-25 14:42 ` [PATCH 7/28] AFS: Update AFS to use new expiry interface Mike Waychison
2004-10-25 14:42 ` [PATCH 8/28] VFS: Remove MNT_EXPIRE support Mike Waychison
2004-10-25 14:43 ` [PATCH 9/28] VFS: Give sane expiry semantics Mike Waychison
2004-10-25 14:43 ` [PATCH 10/28] VFS: Move next_mnt() Mike Waychison
2004-10-25 14:44 ` [PATCH 11/28] VFS: Allow for detachable subtrees Mike Waychison
2004-10-25 14:44 ` [PATCH 12/28] VFS: Remove (now bogus) check_mnt Mike Waychison
2004-10-25 14:45 ` [PATCH 13/28] VFS: Introduce soft reference counts Mike Waychison
2004-10-25 15:25 ` Christoph Hellwig
2004-10-25 15:35 ` [PATCH 14/28] VFS: Introduce Mountpoint file descriptors (resend) Mike Waychison
2004-10-25 17:20 ` [PATCH 13/28] VFS: Introduce soft reference counts Mika Penttilä
2004-10-25 17:25 ` Mike Waychison
2004-10-25 17:52 ` Mika Penttilä
2004-10-25 17:56 ` [PATCH 11/28] VFS: Allow for detachable subtrees (resend) Mike Waychison
2004-10-25 15:09 ` [PATCH 12/28] VFS: Remove (now bogus) check_mnt Christoph Hellwig
2004-10-25 15:15 ` Mike Waychison [this message]
2004-10-25 15:04 ` [PATCH 8/28] VFS: Remove MNT_EXPIRE support Christoph Hellwig
2004-10-25 15:12 ` Mike Waychison
2004-10-25 15:16 ` Christoph Hellwig
2004-10-25 15:30 ` Mike Waychison
2004-10-25 17:16 ` Mike Waychison
2004-10-25 17:29 ` Mike Waychison
2004-10-25 15:04 ` [PATCH 6/28] VFS: Make expiry recursive Christoph Hellwig
2004-10-26 10:27 ` [PATCH 4/28] VFS: Stat shouldn't stop expire Christoph Hellwig
2004-10-27 18:36 ` Mike Waychison
2004-10-25 14:59 ` [PATCH 3/28] VFS: Move expiry into vfs Christoph Hellwig
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