6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
[ Upstream commit 942238f9735a4a4ebf8274b218d9a910158941d1 ]
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: 83301b5367a9 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/unix/af_unix.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 348f9e34f6696..bd2af62f58605 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -617,7 +617,7 @@ 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;
@@ -739,7 +739,8 @@ 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;
@@ -1411,7 +1412,8 @@ 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
@@ -1428,7 +1430,7 @@ 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);
@@ -1644,7 +1646,7 @@ 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() */
@@ -2027,7 +2029,7 @@ 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);
--
2.43.0
