From: Johan Hovold <jhovold@gmail.com>
Date: Tue, 22 Mar 2011 10:12:10 +0000 (+0100)
Subject: USB: cdc-acm: fix potential null-pointer dereference
X-Git-Tag: v2.6.38.2~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c2bf2aa8c59305072aff51fbaa011079f9062c90;p=thirdparty%2Fkernel%2Fstable.git

USB: cdc-acm: fix potential null-pointer dereference

commit 15e5bee33ffc11d0e5c6f819a65e7881c5c407be upstream.

Must check return value of tty_port_tty_get.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 805916675fbc5..fcdd41e0429bb 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -533,6 +533,8 @@ static void acm_softint(struct work_struct *work)
 	if (!ACM_READY(acm))
 		return;
 	tty = tty_port_tty_get(&acm->port);
+	if (!tty)
+		return;
 	tty_wakeup(tty);
 	tty_kref_put(tty);
 }