ipv6: no more dev_put() in inet6_bind()

Avoids touching device refcount in inet6_bind(), thanks to RCU

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 8 deletions

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index b6d058818673..9105b25defe5 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -314,6 +314,7 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                 if (addr_type != IPV6_ADDR_ANY) {
                         struct net_device *dev = NULL;
 
+                        rcu_read_lock();
                         if (addr_type & IPV6_ADDR_LINKLOCAL) {
                                 if (addr_len >= sizeof(struct sockaddr_in6) &&
                                     addr->sin6_scope_id) {
@@ -326,12 +327,12 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                                 /* Binding to link-local address requires an interface */
                                 if (!sk->sk_bound_dev_if) {
                                         err = -EINVAL;
-                                        goto out;
+                                        goto out_unlock;
                                 }
-                                dev = dev_get_by_index(net, sk->sk_bound_dev_if);
+                                dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
                                 if (!dev) {
                                         err = -ENODEV;
-                                        goto out;
+                                        goto out_unlock;
                                 }
                         }
 
@@ -342,14 +343,11 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                         if (!(addr_type & IPV6_ADDR_MULTICAST)) {
                                 if (!ipv6_chk_addr(net, &addr->sin6_addr,
                                                    dev, 0)) {
-                                        if (dev)
-                                                dev_put(dev);
                                         err = -EADDRNOTAVAIL;
-                                        goto out;
+                                        goto out_unlock;
                                 }
                         }
-                        if (dev)
-                                dev_put(dev);
+                        rcu_read_unlock();
                 }
         }
 
@@ -381,6 +379,9 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 out:
         release_sock(sk);
         return err;
+out_unlock:
+        rcu_read_unlock();
+        goto out;
 }
 
 EXPORT_SYMBOL(inet6_bind);