Patch "af_unix: Pass struct sock to unix_autobind()." has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    af_unix: Pass struct sock to unix_autobind().

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     af_unix-pass-struct-sock-to-unix_autobind.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6e28b0638dc4a6110a6b56646b3b62d9619a0076
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx>
Date:   Wed Nov 24 11:14:20 2021 +0900

    af_unix: Pass struct sock to unix_autobind().
    
    [ Upstream commit f7ed31f4615f4e1d97c0e4325c5b8a240e10073c ]
    
    We do not use struct socket in unix_autobind() and pass struct sock to
    unix_bind_bsd() and unix_bind_abstract().  Let's pass it to unix_autobind()
    as well.
    
    Also, this patch fixes these errors by checkpatch.pl.
    
      ERROR: do not use assignment in if condition
      #1795: FILE: net/unix/af_unix.c:1795:
      +     if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
    
      CHECK: Logical continuations should be on the previous line
      #1796: FILE: net/unix/af_unix.c:1796:
      +     if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
      +         && (err = unix_autobind(sock)) != 0)
    
    Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx>
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Stable-dep-of: a9bf9c7dc6a5 ("af_unix: Annotate data-race of sk->sk_state in unix_stream_connect().")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 7d58067ffd3f8..1fc3022510093 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -951,15 +951,13 @@ static int unix_release(struct socket *sock)
 	return 0;
 }
 
-static int unix_autobind(struct socket *sock)
+static int unix_autobind(struct sock *sk)
 {
-	struct sock *sk = sock->sk;
-	struct net *net = sock_net(sk);
 	struct unix_sock *u = unix_sk(sk);
-	static u32 ordernum = 1;
 	struct unix_address *addr;
-	int err;
 	unsigned int retries = 0;
+	static u32 ordernum = 1;
+	int err;
 
 	err = mutex_lock_interruptible(&u->bindlock);
 	if (err)
@@ -986,7 +984,8 @@ static int unix_autobind(struct socket *sock)
 	spin_lock(&unix_table_lock);
 	ordernum = (ordernum+1)&0xFFFFF;
 
-	if (__unix_find_socket_byname(net, addr->name, addr->len, addr->hash)) {
+	if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
+				      addr->hash)) {
 		spin_unlock(&unix_table_lock);
 		/*
 		 * __unix_find_socket_byname() may take long time if many names
@@ -1162,7 +1161,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		return -EINVAL;
 
 	if (addr_len == offsetof(struct sockaddr_un, sun_path))
-		return unix_autobind(sock);
+		return unix_autobind(sk);
 
 	err = unix_mkname(sunaddr, addr_len, &hash);
 	if (err < 0)
@@ -1230,8 +1229,11 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 		alen = err;
 
 		if (test_bit(SOCK_PASSCRED, &sock->flags) &&
-		    !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
-			goto out;
+		    !unix_sk(sk)->addr) {
+			err = unix_autobind(sk);
+			if (err)
+				goto out;
+		}
 
 restart:
 		other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
@@ -1344,9 +1346,11 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 		goto out;
 	addr_len = err;
 
-	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
-	    (err = unix_autobind(sock)) != 0)
-		goto out;
+	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) {
+		err = unix_autobind(sk);
+		if (err)
+			goto out;
+	}
 
 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 
@@ -1798,9 +1802,11 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 			goto out;
 	}
 
-	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
-	    && (err = unix_autobind(sock)) != 0)
-		goto out;
+	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) {
+		err = unix_autobind(sk);
+		if (err)
+			goto out;
+	}
 
 	err = -EMSGSIZE;
 	if (len > sk->sk_sndbuf - 32)