From 5c75633ef751dd4cd8f443dc35152c1ae563162e Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 3 Jan 2017 16:39:55 +0100 Subject: [PATCH] USB: serial: mos7840: 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 mos7840_open+0x88/0x8dc [mos7840] Note that we continue to treat the interrupt-in endpoint as optional for now. Fixes: 3f5429746d91 ("USB: Moschip 7840 USB-Serial Driver") Cc: stable Signed-off-by: Johan Hovold --- drivers/usb/serial/mos7840.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c index 9a220b8e810f..bb933c6321e5 100644 --- a/drivers/usb/serial/mos7840.c +++ b/drivers/usb/serial/mos7840.c @@ -2113,6 +2113,17 @@ 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; @@ -2388,6 +2399,7 @@ 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, -- 2.20.1