af_unix: Annodate data-races around sk->sk_state for writers.

sk->sk_state is changed under unix_state_lock(), but it's read locklessly
in many places.

This patch adds WRITE_ONCE() on the writer side.

We will add READ_ONCE() to the lockless readers in the following patches.

Fixes: 83301b5367 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Kuniyuki Iwashima 2024-06-04 09:52:28 -07:00 committed by Paolo Abeni
parent 26bfb8b570
commit 942238f973

View File

@ -616,7 +616,7 @@ static void unix_release_sock(struct sock *sk, int embrion)
u->path.dentry = NULL;
u->path.mnt = NULL;
state = sk->sk_state;
sk->sk_state = TCP_CLOSE;
WRITE_ONCE(sk->sk_state, TCP_CLOSE);
skpair = unix_peer(sk);
unix_peer(sk) = NULL;
@ -738,7 +738,8 @@ static int unix_listen(struct socket *sock, int backlog)
if (backlog > sk->sk_max_ack_backlog)
wake_up_interruptible_all(&u->peer_wait);
sk->sk_max_ack_backlog = backlog;
sk->sk_state = TCP_LISTEN;
WRITE_ONCE(sk->sk_state, TCP_LISTEN);
/* set credentials so connect can copy them */
init_peercred(sk);
err = 0;
@ -1401,7 +1402,8 @@ restart:
if (err)
goto out_unlock;
sk->sk_state = other->sk_state = TCP_ESTABLISHED;
WRITE_ONCE(sk->sk_state, TCP_ESTABLISHED);
WRITE_ONCE(other->sk_state, TCP_ESTABLISHED);
} else {
/*
* 1003.1g breaking connected state with AF_UNSPEC
@ -1418,7 +1420,7 @@ restart:
unix_peer(sk) = other;
if (!other)
sk->sk_state = TCP_CLOSE;
WRITE_ONCE(sk->sk_state, TCP_CLOSE);
unix_dgram_peer_wake_disconnect_wakeup(sk, old_peer);
unix_state_double_unlock(sk, other);
@ -1639,7 +1641,7 @@ restart:
copy_peercred(sk, other);
sock->state = SS_CONNECTED;
sk->sk_state = TCP_ESTABLISHED;
WRITE_ONCE(sk->sk_state, TCP_ESTABLISHED);
sock_hold(newsk);
smp_mb__after_atomic(); /* sock_hold() does an atomic_inc() */
@ -2050,7 +2052,7 @@ restart_locked:
unix_peer(sk) = NULL;
unix_dgram_peer_wake_disconnect_wakeup(sk, other);
sk->sk_state = TCP_CLOSE;
WRITE_ONCE(sk->sk_state, TCP_CLOSE);
unix_state_unlock(sk);
unix_dgram_disconnected(sk, other);