net/9p: Fix a potential socket leak in p9_socket_open

stable inclusion
from stable-v5.10.158
commit e01c1542379fb395e7da53706df598f38905dfbf
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7NTXH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e01c1542379fb395e7da53706df598f38905dfbf

--------------------------------

[ Upstream commit dcc14cfd ]

Both p9_fd_create_tcp() and p9_fd_create_unix() will call
p9_socket_open(). If the creation of p9_trans_fd fails,
p9_fd_create_tcp() and p9_fd_create_unix() will return an
error directly instead of releasing the cscoket, which will
result in a socket leak.

This patch adds sock_release() to fix the leak issue.

Fixes: 6b18662e ("9p connect fixes")
Signed-off-by: NWang Hai <wanghai38@huawei.com>
ACKed-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>

net/9p/trans_fd.c

@@ -852,8 +852,10 @@ static int p9_socket_open(struct p9_client *client, struct socket *csocket)
 	struct file *file;
 
 	p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
-	if (!p)
+	if (!p) {
+		sock_release(csocket);
 		return -ENOMEM;
+	}
 
 	csocket->sk->sk_allocation = GFP_NOIO;
 	file = sock_alloc_file(csocket, 0, NULL);