Commit 85775787 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman

USB: serial: mos7840: fix NULL-deref at open

commit 5c75633e upstream.

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 mos7840_open+0x88/0x8dc [mos7840]

Note that we continue to treat the interrupt-in endpoint as optional for
now.

Fixes: 3f542974 ("USB: Moschip 7840 USB-Serial Driver")
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1b1fdc71
......@@ -2116,6 +2116,17 @@ static int mos7840_calc_num_ports(struct usb_serial *serial)
return mos7840_num_ports;
}
static int mos7840_attach(struct usb_serial *serial)
{
if (serial->num_bulk_in < serial->num_ports ||
serial->num_bulk_out < serial->num_ports) {
dev_err(&serial->interface->dev, "missing endpoints\n");
return -ENODEV;
}
return 0;
}
static int mos7840_port_probe(struct usb_serial_port *port)
{
struct usb_serial *serial = port->serial;
......@@ -2391,6 +2402,7 @@ static struct usb_serial_driver moschip7840_4port_device = {
.tiocmset = mos7840_tiocmset,
.tiocmiwait = usb_serial_generic_tiocmiwait,
.get_icount = usb_serial_generic_get_icount,
.attach = mos7840_attach,
.port_probe = mos7840_port_probe,
.port_remove = mos7840_port_remove,
.read_bulk_callback = mos7840_bulk_in_callback,
......
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