From: Kuniyuki Iwashima Date: Wed, 13 Jul 2022 20:51:59 +0000 (-0700) Subject: tcp: Fix data-races around sysctl_tcp_l3mdev_accept. X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9ba9cd43b5776c27d25e5a32dde9e80bdeb1c6a1;p=linux.git tcp: Fix data-races around sysctl_tcp_l3mdev_accept. [ Upstream commit 08a75f10679470552a3a443f9aefd1399604d31d ] While reading sysctl_tcp_l3mdev_accept, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 6dd9a14e92e5 ("net: Allow accepted sockets to be bound to l3mdev domain") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index 98e1ec1a14f03..749bb1e460871 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -207,7 +207,7 @@ 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); diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index e71827aa2dfb1..c307a547d2cb4 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -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