Commit d2f011a0 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv6: annotate data-races around np->mcast_oif 



np->mcast_oif is read locklessly in some contexts.

Make all accesses to this field lockless, adding appropriate
annotations.

This also makes setsockopt( IPV6_MULTICAST_IF ) lockless.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9a64d4c9

net/dccp/ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -669,7 +669,7 @@ static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 
ipv6_pktoptions:

	if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {

		if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)

			np->mcast_oif = inet6_iif(opt_skb);

			WRITE_ONCE(np->mcast_oif, inet6_iif(opt_skb));

		if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)

			WRITE_ONCE(np->mcast_hops, ipv6_hdr(opt_skb)->hop_limit);

		if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)

net/ipv6/datagram.c

+2 −2
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ static void ip6_datagram_flow_key_init(struct flowi6 *fl6, 


	if (!oif) {

		if (ipv6_addr_is_multicast(&fl6->daddr))

			oif = np->mcast_oif;

			oif = READ_ONCE(np->mcast_oif);

		else

			oif = np->ucast_oif;

	}
@@ -229,7 +229,7 @@ int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, 
		}



		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))

			WRITE_ONCE(sk->sk_bound_dev_if, np->mcast_oif);

			WRITE_ONCE(sk->sk_bound_dev_if, READ_ONCE(np->mcast_oif));



		/* Connect to link-local address requires an interface */

		if (!sk->sk_bound_dev_if) {

net/ipv6/icmp.c

+2 −2
Original line number Diff line number Diff line
@@ -584,7 +584,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, 
	tmp_hdr.icmp6_pointer = htonl(info);



	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))

		fl6.flowi6_oif = np->mcast_oif;

		fl6.flowi6_oif = READ_ONCE(np->mcast_oif);

	else if (!fl6.flowi6_oif)

		fl6.flowi6_oif = np->ucast_oif;
@@ -770,7 +770,7 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) 
	np = inet6_sk(sk);



	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))

		fl6.flowi6_oif = np->mcast_oif;

		fl6.flowi6_oif = READ_ONCE(np->mcast_oif);

	else if (!fl6.flowi6_oif)

		fl6.flowi6_oif = np->ucast_oif;

net/ipv6/ipv6_sockglue.c

+38 −36
Original line number Diff line number Diff line
@@ -509,6 +509,34 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname, 
		if (optlen < sizeof(int))

			return -EINVAL;

		return ip6_sock_set_addr_preferences(sk, val);

	case IPV6_MULTICAST_IF:

		if (sk->sk_type == SOCK_STREAM)

			return -ENOPROTOOPT;

		if (optlen < sizeof(int))

			return -EINVAL;

		if (val) {

			struct net_device *dev;

			int bound_dev_if, midx;



			rcu_read_lock();



			dev = dev_get_by_index_rcu(net, val);

			if (!dev) {

				rcu_read_unlock();

				return -ENODEV;

			}

			midx = l3mdev_master_ifindex_rcu(dev);



			rcu_read_unlock();



			bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);

			if (bound_dev_if &&

			    bound_dev_if != val &&

			    (!midx || midx != bound_dev_if))

				return -EINVAL;

		}

		WRITE_ONCE(np->mcast_oif, val);

		return 0;

	}

	if (needs_rtnl)

		rtnl_lock();
@@ -860,36 +888,6 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname, 
		break;

	}



	case IPV6_MULTICAST_IF:

		if (sk->sk_type == SOCK_STREAM)

			break;

		if (optlen < sizeof(int))

			goto e_inval;



		if (val) {

			struct net_device *dev;

			int midx;



			rcu_read_lock();



			dev = dev_get_by_index_rcu(net, val);

			if (!dev) {

				rcu_read_unlock();

				retv = -ENODEV;

				break;

			}

			midx = l3mdev_master_ifindex_rcu(dev);



			rcu_read_unlock();



			if (sk->sk_bound_dev_if &&

			    sk->sk_bound_dev_if != val &&

			    (!midx || midx != sk->sk_bound_dev_if))

				goto e_inval;

		}

		np->mcast_oif = val;

		retv = 0;

		break;

	case IPV6_ADD_MEMBERSHIP:

	case IPV6_DROP_MEMBERSHIP:

	{
@@ -1161,10 +1159,12 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, 
		sockopt_release_sock(sk);

		if (!skb) {

			if (np->rxopt.bits.rxinfo) {

				int mcast_oif = READ_ONCE(np->mcast_oif);

				struct in6_pktinfo src_info;

				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :



				src_info.ipi6_ifindex = mcast_oif ? :

					np->sticky_pktinfo.ipi6_ifindex;

				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;

				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;

				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);

			}

			if (np->rxopt.bits.rxhlim) {
@@ -1178,10 +1178,12 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, 
				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);

			}

			if (np->rxopt.bits.rxoinfo) {

				int mcast_oif = READ_ONCE(np->mcast_oif);

				struct in6_pktinfo src_info;

				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :



				src_info.ipi6_ifindex = mcast_oif ? :

					np->sticky_pktinfo.ipi6_ifindex;

				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr :

				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr :

								 np->sticky_pktinfo.ipi6_addr;

				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);

			}
@@ -1359,7 +1361,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, 
		break;



	case IPV6_MULTICAST_IF:

		val = np->mcast_oif;

		val = READ_ONCE(np->mcast_oif);

		break;



	case IPV6_MULTICAST_ALL:

net/ipv6/ping.c

+2 −2
Original line number Diff line number Diff line
@@ -107,7 +107,7 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 
		oif = np->sticky_pktinfo.ipi6_ifindex;



	if (!oif && ipv6_addr_is_multicast(daddr))

		oif = np->mcast_oif;

		oif = READ_ONCE(np->mcast_oif);

	else if (!oif)

		oif = np->ucast_oif;
@@ -157,7 +157,7 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 
	rt = (struct rt6_info *) dst;



	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))

		fl6.flowi6_oif = np->mcast_oif;

		fl6.flowi6_oif = READ_ONCE(np->mcast_oif);

	else if (!fl6.flowi6_oif)

		fl6.flowi6_oif = np->ucast_oif;