USB: serial: oti6858: fix NULL-deref at open

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

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at oti6858_open+0x30/0x1d0 [oti6858]

Note that a missing interrupt-in endpoint would have caused open() to
fail.

Fixes: 49cdee0ed0 ("USB: oti6858 usb-serial driver (in Nokia CA-42
cable)")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2017-01-03 16:39:59 +01:00
parent a5bc01949e
commit 5afeef2366

View File

@ -134,6 +134,7 @@ static int oti6858_chars_in_buffer(struct tty_struct *tty);
static int oti6858_tiocmget(struct tty_struct *tty);
static int oti6858_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear);
static int oti6858_attach(struct usb_serial *serial);
static int oti6858_port_probe(struct usb_serial_port *port);
static int oti6858_port_remove(struct usb_serial_port *port);
@ -158,6 +159,7 @@ static struct usb_serial_driver oti6858_device = {
.write_bulk_callback = oti6858_write_bulk_callback,
.write_room = oti6858_write_room,
.chars_in_buffer = oti6858_chars_in_buffer,
.attach = oti6858_attach,
.port_probe = oti6858_port_probe,
.port_remove = oti6858_port_remove,
};
@ -324,6 +326,20 @@ static void send_data(struct work_struct *work)
usb_serial_port_softint(port);
}
static int oti6858_attach(struct usb_serial *serial)
{
unsigned char num_ports = serial->num_ports;
if (serial->num_bulk_in < num_ports ||
serial->num_bulk_out < num_ports ||
serial->num_interrupt_in < num_ports) {
dev_err(&serial->interface->dev, "missing endpoints\n");
return -ENODEV;
}
return 0;
}
static int oti6858_port_probe(struct usb_serial_port *port)
{
struct oti6858_private *priv;