staging: panel: fix error path

panel_attach() poorly handles errors. On error unregister everything we
have registered.

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 19 insertions, 3 deletions

diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
index aeca01c05e40..3221814a856e 100644
--- a/drivers/staging/panel/panel.c
+++ b/drivers/staging/panel/panel.c
@@ -2124,12 +2124,18 @@ static void panel_attach(struct parport *port)
                                        NULL,
                                        /*PARPORT_DEV_EXCL */
                                        0, (void *)&pprt);
+        if (pprt == NULL) {
+                pr_err("panel_attach(): port->number=%d parport=%d, "
+                       "parport_register_device() failed\n",
+                       port->number, parport);
+                return;
+        }
 
         if (parport_claim(pprt)) {
                 printk(KERN_ERR
                        "Panel: could not claim access to parport%d. "
                        "Aborting.\n", parport);
-                return;
+                goto err_unreg_device;
         }
 
         /* must init LCD first, just in case an IRQ from the keypad is
@@ -2137,13 +2143,23 @@ static void panel_attach(struct parport *port)
          */
         if (lcd_enabled) {
                 lcd_init();
-                misc_register(&lcd_dev);
+                if (misc_register(&lcd_dev))
+                        goto err_unreg_device;
         }
 
         if (keypad_enabled) {
                 keypad_init();
-                misc_register(&keypad_dev);
+                if (misc_register(&keypad_dev))
+                        goto err_lcd_unreg;
         }
+        return;
+
+err_lcd_unreg:
+        if (lcd_enabled)
+                misc_deregister(&lcd_dev);
+err_unreg_device:
+        parport_unregister_device(pprt);
+        pprt = NULL;
 }
 
 static void panel_detach(struct parport *port)