netdev - [PATCH net-next-2.6] ipv6: no more dev_put() in inet6

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 02 Nov 2009 12:10:39 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	"David S. Miller" <davem@...emloft.net>
CC:	Linux Netdev List <netdev@...r.kernel.org>
Subject: [PATCH net-next-2.6] 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@...il.com>
---
 net/ipv6/af_inet6.c |   17 +++++++++--------
 1 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index b6d0588..9105b25 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);
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html