drivers/char/tty_io.c: Avoid panic when no console is configured.

When no console is configured tty_open tries to call kref_get on a NULL pointer, return ENODEV instead. Signed-off-by: Will Newton <[email protected]> Signed-off-by: Alan Cox <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
RyanHsu · Dec 1, 2008 · 296fa7f · 296fa7f
1 parent b4dcfbe
commit 296fa7f
Showing 1 changed file with 9 additions and 6 deletions.
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
@@ -1795,12 +1795,15 @@ static int __tty_open(struct inode *inode, struct file *filp)
 	}
 #endif
 	if (device == MKDEV(TTYAUX_MAJOR, 1)) {
-		driver = tty_driver_kref_get(console_device(&index));
-		if (driver) {
-			/* Don't let /dev/console block */
-			filp->f_flags |= O_NONBLOCK;
-			noctty = 1;
-			goto got_driver;
+		struct tty_driver *console_driver = console_device(&index);
+		if (console_driver) {
+			driver = tty_driver_kref_get(console_driver);
+			if (driver) {
+				/* Don't let /dev/console block */
+				filp->f_flags |= O_NONBLOCK;
+				noctty = 1;
+				goto got_driver;
+			}
 		}
 		mutex_unlock(&tty_mutex);
 		return -ENODEV;