From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:53410 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966216AbeEXJld (ORCPT ); Thu, 24 May 2018 05:41:33 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vasily Averin , "J. Bruce Fields" , Ben Hutchings Subject: [PATCH 3.18 18/45] lockd: lost rollback of set_grace_period() in lockd_down_net() Date: Thu, 24 May 2018 11:38:26 +0200 Message-Id: <20180524093122.781930188@linuxfoundation.org> In-Reply-To: <20180524093120.599252450@linuxfoundation.org> References: <20180524093120.599252450@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vasily Averin commit 3a2b19d1ee5633f76ae8a88da7bc039a5d1732aa upstream. Commit efda760fe95ea ("lockd: fix lockd shutdown race") is incorrect, it removes lockd_manager and disarm grace_period_end for init_net only. If nfsd was started from another net namespace lockd_up_net() calls set_grace_period() that adds lockd_manager into per-netns list and queues grace_period_end delayed work. These action should be reverted in lockd_down_net(). Otherwise it can lead to double list_add on after restart nfsd in netns, and to use-after-free if non-disarmed delayed work will be executed after netns destroy. Fixes: efda760fe95e ("lockd: fix lockd shutdown race") Cc: stable@vger.kernel.org Signed-off-by: Vasily Averin Signed-off-by: J. Bruce Fields Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- fs/lockd/svc.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -271,6 +271,8 @@ static void lockd_down_net(struct svc_se if (ln->nlmsvc_users) { if (--ln->nlmsvc_users == 0) { nlm_shutdown_hosts_net(net); + cancel_delayed_work_sync(&ln->grace_period_end); + locks_end_grace(&ln->lockd_manager); svc_shutdown_net(serv, net); dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net); }