1 files changed, 22 insertions, 22 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index fbd106edbe59..af372d0957fe 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -404,8 +404,8 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
         struct tun_struct *tun;
         struct net_device *dev;
 
-        tun = rcu_dereference_protected(tfile->tun,
-                                        lockdep_rtnl_is_held());
+        tun = rtnl_dereference(tfile->tun);
+
         if (tun) {
                 u16 index = tfile->queue_index;
                 BUG_ON(index >= tun->numqueues);
@@ -414,8 +414,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
                 rcu_assign_pointer(tun->tfiles[index],
                                    tun->tfiles[tun->numqueues - 1]);
                 rcu_assign_pointer(tfile->tun, NULL);
-                ntfile = rcu_dereference_protected(tun->tfiles[index],
-                                                   lockdep_rtnl_is_held());
+                ntfile = rtnl_dereference(tun->tfiles[index]);
                 ntfile->queue_index = index;
 
                 --tun->numqueues;
@@ -429,8 +428,10 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
                 /* Drop read queue */
                 skb_queue_purge(&tfile->sk.sk_receive_queue);
                 tun_set_real_num_queues(tun);
-        } else if (tfile->detached && clean)
+        } else if (tfile->detached && clean) {
                 tun = tun_enable_queue(tfile);
+                sock_put(&tfile->sk);
+        }
 
         if (clean) {
                 if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
@@ -458,8 +459,7 @@ static void tun_detach_all(struct net_device *dev)
         int i, n = tun->numqueues;
 
         for (i = 0; i < n; i++) {
-                tfile = rcu_dereference_protected(tun->tfiles[i],
-                                                  lockdep_rtnl_is_held());
+                tfile = rtnl_dereference(tun->tfiles[i]);
                 BUG_ON(!tfile);
                 wake_up_all(&tfile->wq.wait);
                 rcu_assign_pointer(tfile->tun, NULL);
@@ -469,8 +469,7 @@ static void tun_detach_all(struct net_device *dev)
 
         synchronize_net();
         for (i = 0; i < n; i++) {
-                tfile = rcu_dereference_protected(tun->tfiles[i],
-                                                  lockdep_rtnl_is_held());
+                tfile = rtnl_dereference(tun->tfiles[i]);
                 /* Drop read queue */
                 skb_queue_purge(&tfile->sk.sk_receive_queue);
                 sock_put(&tfile->sk);
@@ -481,6 +480,9 @@ static void tun_detach_all(struct net_device *dev)
                 sock_put(&tfile->sk);
         }
         BUG_ON(tun->numdisabled != 0);
+
+        if (tun->flags & TUN_PERSIST)
+                module_put(THIS_MODULE);
 }
 
 static int tun_attach(struct tun_struct *tun, struct file *file)
@@ -489,7 +491,7 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
         int err;
 
         err = -EINVAL;
-        if (rcu_dereference_protected(tfile->tun, lockdep_rtnl_is_held()))
+        if (rtnl_dereference(tfile->tun))
                 goto out;
 
         err = -EBUSY;
@@ -1544,6 +1546,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
         struct net_device *dev;
         int err;
 
+        if (tfile->detached)
+                return -EINVAL;
+
         dev = __dev_get_by_name(net, ifr->ifr_name);
         if (dev) {
                 if (ifr->ifr_flags & IFF_TUN_EXCL)
@@ -1738,8 +1743,7 @@ static void tun_detach_filter(struct tun_struct *tun, int n)
         struct tun_file *tfile;
 
         for (i = 0; i < n; i++) {
-                tfile = rcu_dereference_protected(tun->tfiles[i],
-                                                  lockdep_rtnl_is_held());
+                tfile = rtnl_dereference(tun->tfiles[i]);
                 sk_detach_filter(tfile->socket.sk);
         }
 
@@ -1752,8 +1756,7 @@ static int tun_attach_filter(struct tun_struct *tun)
         struct tun_file *tfile;
 
         for (i = 0; i < tun->numqueues; i++) {
-                tfile = rcu_dereference_protected(tun->tfiles[i],
-                                                  lockdep_rtnl_is_held());
+                tfile = rtnl_dereference(tun->tfiles[i]);
                 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
                 if (ret) {
                         tun_detach_filter(tun, i);
@@ -1771,8 +1774,7 @@ static void tun_set_sndbuf(struct tun_struct *tun)
         int i;
 
         for (i = 0; i < tun->numqueues; i++) {
-                tfile = rcu_dereference_protected(tun->tfiles[i],
-                                                lockdep_rtnl_is_held());
+                tfile = rtnl_dereference(tun->tfiles[i]);
                 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
         }
 }
@@ -1789,13 +1791,10 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
                 tun = tfile->detached;
                 if (!tun)
                         ret = -EINVAL;
-                else if (tun_not_capable(tun))
-                        ret = -EPERM;
                 else
                         ret = tun_attach(tun, file);
         } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
-                tun = rcu_dereference_protected(tfile->tun,
-                                                lockdep_rtnl_is_held());
+                tun = rtnl_dereference(tfile->tun);
                 if (!tun || !(tun->flags & TUN_TAP_MQ))
                         ret = -EINVAL;
                 else
@@ -1880,10 +1879,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
                 /* Disable/Enable persist mode. Keep an extra reference to the
                  * module to prevent the module being unprobed.
                  */
-                if (arg) {
+                if (arg && !(tun->flags & TUN_PERSIST)) {
                         tun->flags |= TUN_PERSIST;
                         __module_get(THIS_MODULE);
-                } else {
+                }
+                if (!arg && (tun->flags & TUN_PERSIST)) {
                         tun->flags &= ~TUN_PERSIST;
                         module_put(THIS_MODULE);
                 }