Commit 08a75f10 authored Jul 13, 2022 by Kuniyuki Iwashima Committed by David S. Miller Jul 15, 2022

tcp: Fix data-races around sysctl_tcp_l3mdev_accept.



While reading sysctl_tcp_l3mdev_accept, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 6dd9a14e ("net: Allow accepted sockets to be bound to l3mdev domain")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 1a0008f9

include/net/inet_hashtables.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -179,7 +179,7 @@ static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,
		int dif, int sdif)
		{
		#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
		return inet_bound_dev_eq(!!net->ipv4.sysctl_tcp_l3mdev_accept,
		return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
		bound_dev_if, dif, sdif);
		#else
		return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);

include/net/inet_sock.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -121,7 +121,7 @@ static inline int inet_request_bound_dev_if(const struct sock *sk,
		#ifdef CONFIG_NET_L3_MASTER_DEV
		struct net *net = sock_net(sk);

		if (!bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
		if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
		return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
		#endif

		@@ -133,7 +133,7 @@ static inline int inet_sk_bound_l3mdev(const struct sock *sk)
		#ifdef CONFIG_NET_L3_MASTER_DEV
		struct net *net = sock_net(sk);

		if (!net->ipv4.sysctl_tcp_l3mdev_accept)
		if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
		return l3mdev_master_ifindex_by_index(net,
		sk->sk_bound_dev_if);
		#endif