From: Johan Hovold <johan@kernel.org>
Date: Fri, 21 Oct 2016 10:56:27 +0000 (+0200)
Subject: USB: serial: fix potential NULL-dereference at probe
X-Git-Tag: v4.1.36~43
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7fbfac87fbf5b452c7c9ba3c4a566a41dca032e2;p=platform%2Fkernel%2Flinux-exynos.git

USB: serial: fix potential NULL-dereference at probe

[ Upstream commit 126d26f66d9890a69158812a6caa248c05359daa ]

Make sure we have at least one port before attempting to register a
console.

Currently, at least one driver binds to a "dummy" interface and requests
zero ports for it. Should such an interface also lack endpoints, we get
a NULL-deref during probe.

Fixes: e5b1e2062e05 ("USB: serial: make minor allocation dynamic")
Cc: stable <stable@vger.kernel.org>	# 3.11
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index a0ca291..e7e29c7 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -1077,7 +1077,8 @@ static int usb_serial_probe(struct usb_interface *interface,
 
 	serial->disconnected = 0;
 
-	usb_serial_console_init(serial->port[0]->minor);
+	if (num_ports > 0)
+		usb_serial_console_init(serial->port[0]->minor);
 exit:
 	module_put(type->driver.owner);
 	return 0;