Revert "smb: client: Fix netns refcount imbalance causing leaks and use-after-free"

This reverts commit 4e7f1644f2ac6d01dc584f6301c3b1d5aac4eaef.

The commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after
rmmod") is not only a bogus fix for LOCKDEP null-ptr-deref but also
introduces a real issue, TCP sockets leak, which will be explained in
detail in the next revert.

Also, CNA assigned CVE-2024-54680 to it but is rejecting it. [0]

Thus, we are reverting the commit and its follow-up commit 4e7f1644f2ac
("smb: client: Fix netns refcount imbalance causing leaks and
use-after-free").

Link: https://lore.kernel.org/all/2025040248-tummy-smilingly-4240@gregkh/ #[0]
Fixes: 4e7f1644f2ac ("smb: client: Fix netns refcount imbalance causing leaks and use-after-free")
Signed-off-by: Kuniyuki Iwashima <[e-mail]>
Cc: [e-mail]
Signed-off-by: Steve French <[e-mail]>

fs/smb/client/connect.c

···
 			 server->ssocket->flags);
 		sock_release(server->ssocket);
 		server->ssocket = NULL;
-		put_net(cifs_net_ns(server));
 	}
 	server->sequence_number = 0;
 	server->session_estab = false;
···
 		/*
 		 * Grab netns reference for the socket.
 		 *
-		 * This reference will be released in several situations:
-		 * - In the failure path before the cifsd thread is started.
-		 * - In the all place where server->socket is released, it is
-		 *   also set to NULL.
-		 * - Ultimately in clean_demultiplex_info(), during the final
-		 *   teardown.
+		 * It'll be released here, on error, or in clean_demultiplex_info() upon server
+		 * teardown.
 		 */
 		get_net(net);
 
···
 	}
 
 	rc = bind_socket(server);
-	if (rc < 0)
+	if (rc < 0) {
+		put_net(cifs_net_ns(server));
 		return rc;
+	}
 
 	/*
 	 * Eventually check for other socket options to change from
···
 	    server->rfc1001_sessinit == 1 ||
 	    (server->rfc1001_sessinit == -1 && sport == htons(RFC1001_PORT)))
 		rc = ip_rfc1001_connect(server);
+
+	if (rc < 0)
+		put_net(cifs_net_ns(server));
 
 	return rc;
 }