From c5b8f9b75d8908220f1bedcfd99843f4930fb094 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 13 Jul 2022 13:51:59 -0700 Subject: [PATCH] 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: ddf3fa7765d7 ("net: Allow accepted sockets to be bound to l3mdev domain") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller --- include/net/inet_hashtables.h | 2 +- include/net/inet_sock.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index ebfa3df6f8dc3..fd6b510d114bc 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -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); diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index b29108f0973ad..6395f6b9a5d29 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 -- 2.39.5