linux-kernel - Re: do_remount_sb(RDONLY) race? (was: XFS oops under 2.6.23.9)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Wed, 23 Jan 2008 12:55:04 +0000
From:	Christoph Hellwig <hch@...radead.org>
To:	David Chinner <dgc@....com>
Cc:	Jonathan Woithe <jwoithe@...sics.adelaide.edu.au>,
	linux-kernel@...r.kernel.org
Subject: Re: do_remount_sb(RDONLY) race? (was: XFS oops under 2.6.23.9)

On Wed, Jan 23, 2008 at 04:34:12PM +1100, David Chinner wrote:
> I've had suspicions of a race in the remount-ro code in
> do_remount_sb() w.r.t to the fs_may_remount_ro() check.  That is, we
> do an unlocked check to see if we can remount readonly and then fail
> to check again once we've locked the superblock out and start the
> remount.

This code is inherently racy, and will be replaced with a proper
per-vfsmount writer count in 2.6.25 as part of the per-mount r/o patches.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/