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 commit efda760fe95e ("lockd: fix lockd shutdown race")
Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
---
fs/lockd/svc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index c1573860..809cbcc 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -277,6 +277,8 @@ static void lockd_down_net(struct svc_serv *serv, struct net *net)
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);
}
--
2.7.4
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