This is a note to let you know that I've just added the patch titled
tcp: sk->sk_bound_dev_if once in inet_request_bound_dev_if()
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp-sk-sk_bound_dev_if-once-in-inet_request_bound_de.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7f8905fc5824cd3a22952b1b05f4b8cc279457a5
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri May 13 11:55:43 2022 -0700
tcp: sk->sk_bound_dev_if once in inet_request_bound_dev_if()
[ Upstream commit fdb5fd7f736ec7ae9fb36d2842ea6d9ebc4e7269 ]
inet_request_bound_dev_if() reads sk->sk_bound_dev_if twice
while listener socket is not locked.
Another cpu could change this field under us.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index d3cf5871289b..b29108f0973a 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -117,14 +117,15 @@ static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
static inline int inet_request_bound_dev_if(const struct sock *sk,
struct sk_buff *skb)
{
+ int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
#ifdef CONFIG_NET_L3_MASTER_DEV
struct net *net = sock_net(sk);
- if (!sk->sk_bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
+ if (!bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
#endif
- return sk->sk_bound_dev_if;
+ return bound_dev_if;
}
static inline int inet_sk_bound_l3mdev(const struct sock *sk)
