Commit e5fccaa1 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: core: add READ_ONCE/WRITE_ONCE annotations for sk->sk_bound_dev_if 



sock_bindtoindex_locked() needs to use WRITE_ONCE(sk->sk_bound_dev_if, val),
because other cpus/threads might locklessly read this field.

sock_getbindtodevice(), sock_getsockopt() need READ_ONCE()
because they run without socket lock held.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fdb5fd7f

net/core/sock.c

+7 −4
Original line number Diff line number Diff line
@@ -635,7 +635,9 @@ static int sock_bindtoindex_locked(struct sock *sk, int ifindex) 
	if (ifindex < 0)

		goto out;



	sk->sk_bound_dev_if = ifindex;

	/* Paired with all READ_ONCE() done locklessly. */

	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);



	if (sk->sk_prot->rehash)

		sk->sk_prot->rehash(sk);

	sk_dst_reset(sk);
@@ -713,10 +715,11 @@ static int sock_getbindtodevice(struct sock *sk, char __user *optval, 
{

	int ret = -ENOPROTOOPT;

#ifdef CONFIG_NETDEVICES

	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);

	struct net *net = sock_net(sk);

	char devname[IFNAMSIZ];



	if (sk->sk_bound_dev_if == 0) {

	if (bound_dev_if == 0) {

		len = 0;

		goto zero;

	}
@@ -725,7 +728,7 @@ static int sock_getbindtodevice(struct sock *sk, char __user *optval, 
	if (len < IFNAMSIZ)

		goto out;



	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);

	ret = netdev_get_name(net, devname, bound_dev_if);

	if (ret)

		goto out;
@@ -1861,7 +1864,7 @@ int sock_getsockopt(struct socket *sock, int level, int optname, 
		break;



	case SO_BINDTOIFINDEX:

		v.val = sk->sk_bound_dev_if;

		v.val = READ_ONCE(sk->sk_bound_dev_if);

		break;



	case SO_NETNS_COOKIE: