Commit 942238f9 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Paolo Abeni
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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: 83301b53 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 26bfb8b5

net/unix/af_unix.c

+8 −6
Original line number Diff line number Diff line
@@ -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 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, 
		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 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, 


		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 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, 
	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 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, 
			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);