Commit 33dcee99 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'af_unix-fix-two-data-races-reported-by-kcsan' 

Kuniyuki Iwashima says:

====================
af_unix: Fix two data races reported by KCSAN.

KCSAN reported data races around these two fields for AF_UNIX sockets.

  * sk->sk_receive_queue->qlen
  * sk->sk_shutdown

Let's annotate them properly.
====================

Link: https://lore.kernel.org/r/20230510003456.42357-1-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 5bca1d08 e1d09c2c

net/unix/af_unix.c

+13 −9
Original line number Diff line number Diff line
@@ -603,7 +603,7 @@ static void unix_release_sock(struct sock *sk, int embrion) 
	/* Clear state */

	unix_state_lock(sk);

	sock_orphan(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;

	WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);

	path	     = u->path;

	u->path.dentry = NULL;

	u->path.mnt = NULL;
@@ -628,7 +628,7 @@ static void unix_release_sock(struct sock *sk, int embrion) 
		if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {

			unix_state_lock(skpair);

			/* No more writes */

			skpair->sk_shutdown = SHUTDOWN_MASK;

			WRITE_ONCE(skpair->sk_shutdown, SHUTDOWN_MASK);

			if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)

				WRITE_ONCE(skpair->sk_err, ECONNRESET);

			unix_state_unlock(skpair);
@@ -1442,7 +1442,7 @@ static long unix_wait_for_peer(struct sock *other, long timeo) 


	sched = !sock_flag(other, SOCK_DEAD) &&

		!(other->sk_shutdown & RCV_SHUTDOWN) &&

		unix_recvq_full(other);

		unix_recvq_full_lockless(other);



	unix_state_unlock(other);
@@ -3008,7 +3008,7 @@ static int unix_shutdown(struct socket *sock, int mode) 
	++mode;



	unix_state_lock(sk);

	sk->sk_shutdown |= mode;

	WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | mode);

	other = unix_peer(sk);

	if (other)

		sock_hold(other);
@@ -3028,7 +3028,7 @@ static int unix_shutdown(struct socket *sock, int mode) 
		if (mode&SEND_SHUTDOWN)

			peer_mode |= RCV_SHUTDOWN;

		unix_state_lock(other);

		other->sk_shutdown |= peer_mode;

		WRITE_ONCE(other->sk_shutdown, other->sk_shutdown | peer_mode);

		unix_state_unlock(other);

		other->sk_state_change(other);

		if (peer_mode == SHUTDOWN_MASK)
@@ -3160,16 +3160,18 @@ static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wa 
{

	struct sock *sk = sock->sk;

	__poll_t mask;

	u8 shutdown;



	sock_poll_wait(file, sock, wait);

	mask = 0;

	shutdown = READ_ONCE(sk->sk_shutdown);



	/* exceptional events? */

	if (READ_ONCE(sk->sk_err))

		mask |= EPOLLERR;

	if (sk->sk_shutdown == SHUTDOWN_MASK)

	if (shutdown == SHUTDOWN_MASK)

		mask |= EPOLLHUP;

	if (sk->sk_shutdown & RCV_SHUTDOWN)

	if (shutdown & RCV_SHUTDOWN)

		mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;



	/* readable? */
@@ -3203,9 +3205,11 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock, 
	struct sock *sk = sock->sk, *other;

	unsigned int writable;

	__poll_t mask;

	u8 shutdown;



	sock_poll_wait(file, sock, wait);

	mask = 0;

	shutdown = READ_ONCE(sk->sk_shutdown);



	/* exceptional events? */

	if (READ_ONCE(sk->sk_err) ||
@@ -3213,9 +3217,9 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock, 
		mask |= EPOLLERR |

			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);



	if (sk->sk_shutdown & RCV_SHUTDOWN)

	if (shutdown & RCV_SHUTDOWN)

		mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;

	if (sk->sk_shutdown == SHUTDOWN_MASK)

	if (shutdown == SHUTDOWN_MASK)

		mask |= EPOLLHUP;



	/* readable? */