USB: serial: ti_usb_3410_5052: fix NULL-deref at open
authorJohan Hovold <johan@kernel.org>
Tue, 3 Jan 2017 15:40:03 +0000 (16:40 +0100)
committerBen Hutchings <ben@decadent.org.uk>
Thu, 16 Mar 2017 02:18:38 +0000 (02:18 +0000)
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>
drivers/usb/serial/ti_usb_3410_5052.c

index ad0445a..6bf24d1 100644 (file)
@@ -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);