Patch "lockd: lost rollback of set_grace_period() in lockd_down_net()" has been added to the 4.14-stable tree

Patch "lockd: lost rollback of set_grace_period() in lockd_down_net()" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    lockd: lost rollback of set_grace_period() in lockd_down_net()

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     lockd-lost-rollback-of-set_grace_period-in-lockd_down_net.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 3a2b19d1ee5633f76ae8a88da7bc039a5d1732aa Mon Sep 17 00:00:00 2001
From: Vasily Averin <vvs@virtuozzo.com>
Date: Thu, 2 Nov 2017 13:03:42 +0300
Subject: lockd: lost rollback of set_grace_period() in lockd_down_net()

From: Vasily Averin <vvs@virtuozzo.com>

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")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/lockd/svc.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -274,6 +274,8 @@ 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);
 		}


Patches currently in stable-queue which might be from vvs@virtuozzo.com are

queue-4.14/lockd-lost-rollback-of-set_grace_period-in-lockd_down_net.patch