From: Johan Hovold <johan@kernel.org>
Date: Tue, 3 Jan 2017 15:40:03 +0000 (+0100)
Subject: USB: serial: ti_usb_3410_5052: fix NULL-deref at open
X-Git-Tag: v3.2.87~119
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=666d227806459ca178441873f3b1b57cda39e2af

USB: serial: ti_usb_3410_5052: fix NULL-deref at open

commit ef079936d3cd09e63612834fe2698eeada0d8e3f upstream.

Fix NULL-pointer dereference in open() should a malicious device lack
the expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
..
[<bf06a6b0>] (ti_open [ti_usb_3410_5052]) from [<bf02e118>] (serial_port_activate+0x68/0x98 [usbserial])

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index ad0445a68a02..6bf24d10324c 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -438,6 +438,13 @@ static int ti_startup(struct usb_serial *serial)
 		goto free_tdev;
 	}
 
+	if (serial->num_bulk_in < serial->num_ports ||
+			serial->num_bulk_out < serial->num_ports) {
+		dev_err(&serial->interface->dev, "missing endpoints\n");
+		status = -ENODEV;
+		goto free_tdev;
+	}
+
 	/* set up port structures */
 	for (i = 0; i < serial->num_ports; ++i) {
 		tport = kzalloc(sizeof(struct ti_port), GFP_KERNEL);