drivers/tty: add error handling for pcmcia_loop_config

BugLink: https://bugs.launchpad.net/bugs/1798770

[ Upstream commit 85c634e9 ]

When pcmcia_loop_config fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling pcmcia_loop_config.
Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/tty/serial/8250/serial_cs.c

@@ -629,8 +629,10 @@ static int serial_config(struct pcmcia_device * link)
 	    (link->has_func_id) &&
 	    (link->socket->pcmcia_pfc == 0) &&
 	    ((link->func_id == CISTPL_FUNCID_MULTI) ||
-	     (link->func_id == CISTPL_FUNCID_SERIAL)))
-		pcmcia_loop_config(link, serial_check_for_multi, info);
+	     (link->func_id == CISTPL_FUNCID_SERIAL))) {
+		if (pcmcia_loop_config(link, serial_check_for_multi, info))
+			goto failed;
+	}
 
 	/*
 	 * Apply any multi-port quirk.