Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.18 040/158] tcp: sk->sk_bound_dev_if once in inet_request_bound_dev_if() | Date | Wed, 27 Jul 2022 18:11:44 +0200 |
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From: Eric Dumazet <edumazet@google.com>
[ 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@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- include/net/inet_sock.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
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) -- 2.35.1
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