From: Vasily Averin <vvs@virtuozzo.com>

Date: Fri, 20 Oct 2017 17:33:18 +0300

Subject: [PATCH] lockd: double unregister of inetaddr notifiers

Git-commit: dc3033e16c59a2c4e62b31341258a5786cbcee56

Patch-mainline: v4.15

References: git-fixes

lockd_up() can call lockd_unregister_notifiers twice:

inside lockd_start_svc() when it calls lockd_svc_exit_thread()

and then in error path of lockd_up()

Patch forces lockd_start_svc() to unregister notifiers in all error cases

and removes extra unregister in error path of lockd_up().

Fixes: cb7d224f82e4 "lockd: unregister notifier blocks if the service ..."

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>

Cc: stable@vger.kernel.org

Reviewed-by: Jeff Layton <jlayton@kernel.org>

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Acked-by: NeilBrown <neilb@suse.com>

---

 fs/lockd/svc.c |   20 +++++++++-----------

 1 file changed, 9 insertions(+), 11 deletions(-)

--- a/fs/lockd/svc.c

+++ b/fs/lockd/svc.c

@@ -369,6 +369,7 @@ static int lockd_start_svc(struct svc_se

 		printk(KERN_WARNING

 			"lockd_up: svc_rqst allocation failed, error=%d\n",

 			error);

+		lockd_unregister_notifiers();

 		goto out_rqst;

 	}

@@ -459,13 +460,16 @@ int lockd_up(struct net *net)

 	}

 	error = lockd_up_net(serv, net);

-	if (error < 0)

-		goto err_net;

+	if (error < 0) {

+		lockd_unregister_notifiers();

+		goto err_put;

+	}

 	error = lockd_start_svc(serv);

-	if (error < 0)

-		goto err_start;

-

+	if (error < 0) {

+		lockd_down_net(serv, net);

+		goto err_put;

+	}

 	nlmsvc_users++;

 	/*

 	 * Note: svc_serv structures have an initial use count of 1,

@@ -476,12 +480,6 @@ err_put:

 err_create:

 	mutex_unlock(&nlmsvc_mutex);

 	return error;

-

-err_start:

-	lockd_down_net(serv, net);

-err_net:

-	lockd_unregister_notifiers();

-	goto err_put;

 }

 EXPORT_SYMBOL_GPL(lockd_up);