From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold Subject: [PATCH 4.4 042/101] USB: serial: mos7840: fix NULL-deref at open Date: Tue, 10 Jan 2017 14:36:55 +0100 Message-Id: <20170110131524.313257498@linuxfoundation.org> In-Reply-To: <20170110131522.493717794@linuxfoundation.org> References: <20170110131522.493717794@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 5c75633ef751dd4cd8f443dc35152c1ae563162e 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: 3f5429746d91 ("USB: Moschip 7840 USB-Serial Driver") Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/mos7840.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/usb/serial/mos7840.c +++ b/drivers/usb/serial/mos7840.c @@ -2116,6 +2116,17 @@ static int mos7840_calc_num_ports(struct 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 moschip7 .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,