From: Vasily Averin Date: Thu, 2 Nov 2017 10:03:42 +0000 (+0300) Subject: lockd: lost rollback of set_grace_period() in lockd_down_net() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=84779085fa10014b9e8208d7e71b54bced73075c;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git lockd: lost rollback of set_grace_period() in lockd_down_net() 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 Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index f04ecfc7ece0..45e96549ebd2 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -274,6 +274,8 @@ 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); }