5.15-stable review patch. If anyone has any objections, please let me know.
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From: Kuniyuki Iwashima kuniyu@amazon.com
[ 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@amazon.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 914e40697f00a..616d6c34d6102 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -542,7 +542,7 @@ 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; @@ -664,7 +664,8 @@ 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; @@ -1254,7 +1255,8 @@ 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 @@ -1271,7 +1273,7 @@ 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); @@ -1484,7 +1486,7 @@ 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() */ @@ -1880,7 +1882,7 @@ 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);