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

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 <[email protected]> know about it.

From: Vasily Averin <[email protected]>
Date: Thu, 2 Nov 2017 13:03:42 +0300
Subject: lockd: lost rollback of set_grace_period() in lockd_down_net()

From: Vasily Averin <[email protected]>

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.

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

@@ -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 [email protected] are

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