linux-kernel - Re: [ 16/46] NFSv4.1: Remove a bogus BUG_ON() in nfs4_layoutreturn

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

Message-ID: <1347813183.13258.286.camel@deadeye.wl.decadent.org.uk>
Date:	Sun, 16 Sep 2012 17:33:03 +0100
From:	Ben Hutchings <ben@...adent.org.uk>
To:	Trond Myklebust <Trond.Myklebust@...app.com>
Cc:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	Boaz Harrosh <bharrosh@...asas.com>,
	Tigran Mkrtchyan <tigran.mkrtchyan@...y.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [ 16/46] NFSv4.1: Remove a bogus BUG_ON() in
 nfs4_layoutreturn_done

On Wed, 2012-09-12 at 16:39 -0700, Greg Kroah-Hartman wrote:
> From: Greg KH <gregkh@...uxfoundation.org>
> 
> 3.0-stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Trond Myklebust <Trond.Myklebust@...app.com>
> 
> commit 47fbf7976e0b7d9dcdd799e2a1baba19064d9631 upstream.
> 
> Ever since commit 0a57cdac3f (NFSv4.1 send layoutreturn to fence
> disconnected data server) we've been sending layoutreturn calls
> while there is potentially still outstanding I/O to the data
> servers. The reason we do this is to avoid races between replayed
> writes to the MDS and the original writes to the DS.
> 
> When this happens, the BUG_ON() in nfs4_layoutreturn_done can
> be triggered because it assumes that we would never call
> layoutreturn without knowing that all I/O to the DS is
> finished. The fix is to remove the BUG_ON() now that the
> assumptions behind the test are obsolete.
> 
> Reported-by: Boaz Harrosh <bharrosh@...asas.com>
> Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@...y.de>
> Signed-off-by: Trond Myklebust <Trond.Myklebust@...app.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
[...]

The upstream commit has:

    Cc: stable@...r.kernel.org [>=3.5]

and so I ignored it for 3.2.  Is it actually needed for the earlier
stable series?

Ben.

-- 
Ben Hutchings
Experience is what causes a person to make new mistakes instead of old ones.

Download attachment "signature.asc" of type "application/pgp-signature" (829 bytes)