From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 01/10] locks: close potential race in lease_get_mtime Date: Sun, 24 Aug 2014 08:48:17 -0700 Message-ID: <20140824154817.GA15908@infradead.org> References: <1408804878-1331-1-git-send-email-jlayton@primarydata.com> <1408804878-1331-2-git-send-email-jlayton@primarydata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, cluster-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jeff Layton Return-path: Content-Disposition: inline In-Reply-To: <1408804878-1331-2-git-send-email-jlayton-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On Sat, Aug 23, 2014 at 10:41:09AM -0400, Jeff Layton wrote: > lease_get_mtime is called without the i_lock held, so there's no > guarantee about the stability of the list. Between the time when we > assign "flock" and then dereference it to check whether it's a lease > and for write, the lease could be freed. > > Ensure that that doesn't occur by taking the i_lock before trying > to check the lease. Looks good. Also looks way cleaner than before by being just a tad more verbose.. Reviewed-by: Christoph Hellwig From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from bombadil.infradead.org ([198.137.202.9]:57626 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752789AbaHXPsR (ORCPT ); Sun, 24 Aug 2014 11:48:17 -0400 Date: Sun, 24 Aug 2014 08:48:17 -0700 From: Christoph Hellwig To: Jeff Layton Cc: linux-fsdevel@vger.kernel.org, bfields@fieldses.org, hch@infradead.org, cluster-devel@redhat.com, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org Subject: Re: [PATCH 01/10] locks: close potential race in lease_get_mtime Message-ID: <20140824154817.GA15908@infradead.org> References: <1408804878-1331-1-git-send-email-jlayton@primarydata.com> <1408804878-1331-2-git-send-email-jlayton@primarydata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1408804878-1331-2-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Sat, Aug 23, 2014 at 10:41:09AM -0400, Jeff Layton wrote: > lease_get_mtime is called without the i_lock held, so there's no > guarantee about the stability of the list. Between the time when we > assign "flock" and then dereference it to check whether it's a lease > and for write, the lease could be freed. > > Ensure that that doesn't occur by taking the i_lock before trying > to check the lease. Looks good. Also looks way cleaner than before by being just a tad more verbose.. Reviewed-by: Christoph Hellwig From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Sun, 24 Aug 2014 08:48:17 -0700 Subject: [Cluster-devel] [PATCH 01/10] locks: close potential race in lease_get_mtime In-Reply-To: <1408804878-1331-2-git-send-email-jlayton@primarydata.com> References: <1408804878-1331-1-git-send-email-jlayton@primarydata.com> <1408804878-1331-2-git-send-email-jlayton@primarydata.com> Message-ID: <20140824154817.GA15908@infradead.org> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Sat, Aug 23, 2014 at 10:41:09AM -0400, Jeff Layton wrote: > lease_get_mtime is called without the i_lock held, so there's no > guarantee about the stability of the list. Between the time when we > assign "flock" and then dereference it to check whether it's a lease > and for write, the lease could be freed. > > Ensure that that doesn't occur by taking the i_lock before trying > to check the lease. Looks good. Also looks way cleaner than before by being just a tad more verbose.. Reviewed-by: Christoph Hellwig