From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 4177f545895b1da08447a80692f30617154efa6e ]
While reading sysctl_tcp_migrate_req, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: f9ac779f881c ("net: Introduce net.ipv4.tcp_migrate_req.") Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/sock_reuseport.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c index 3f00a28fe762..5daa1fa54249 100644 --- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -387,7 +387,7 @@ void reuseport_stop_listen_sock(struct sock *sk) prog = rcu_dereference_protected(reuse->prog, lockdep_is_held(&reuseport_lock));
- if (sock_net(sk)->ipv4.sysctl_tcp_migrate_req || + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_migrate_req) || (prog && prog->expected_attach_type == BPF_SK_REUSEPORT_SELECT_OR_MIGRATE)) { /* Migration capable, move sk from the listening section * to the closed section. @@ -545,7 +545,7 @@ struct sock *reuseport_migrate_sock(struct sock *sk, hash = migrating_sk->sk_hash; prog = rcu_dereference(reuse->prog); if (!prog || prog->expected_attach_type != BPF_SK_REUSEPORT_SELECT_OR_MIGRATE) { - if (sock_net(sk)->ipv4.sysctl_tcp_migrate_req) + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_migrate_req)) goto select_by_hash; goto failure; }