From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 24 Jul 2012 11:52:04 +0000 (+0100)
Subject: tty: handle NULL parameters in free_tty_struct()
X-Git-Tag: firefly_0821_release~3680^2~1976^2~169
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=dc6802a771e91050fb686dfeeb9de4c6c9cadb79;p=firefly-linux-kernel-4.4.55.git

tty: handle NULL parameters in free_tty_struct()

We sometimes pass NULL pointers to free_tty_struct().  One example where
it can happen is in the error handling code in pty_common_install().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 608749978df4..6784aae210e3 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -181,6 +181,8 @@ struct tty_struct *alloc_tty_struct(void)
 
 void free_tty_struct(struct tty_struct *tty)
 {
+	if (!tty)
+		return;
 	if (tty->dev)
 		put_device(tty->dev);
 	kfree(tty->write_buf);