Patch "USB: serial: mos7840: fix NULL-deref at open" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

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

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-serial-mos7840-fix-null-deref-at-open.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 5c75633ef751dd4cd8f443dc35152c1ae563162e Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Tue, 3 Jan 2017 16:39:55 +0100
Subject: USB: serial: mos7840: fix NULL-deref at open

From: Johan Hovold <johan@kernel.org>

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 <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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,


Patches currently in stable-queue which might be from johan@kernel.org are

queue-4.4/usb-serial-io_ti-fix-i-o-after-disconnect.patch
queue-4.4/usb-serial-ti_usb_3410_5052-fix-null-deref-at-open.patch
queue-4.4/usb-serial-kobil_sct-fix-null-deref-in-write.patch
queue-4.4/usb-serial-spcp8x5-fix-null-deref-at-open.patch
queue-4.4/usb-serial-mos7720-fix-parallel-probe.patch
queue-4.4/usb-serial-cyberjack-fix-null-deref-at-open.patch
queue-4.4/usb-serial-mos7720-fix-null-deref-at-open.patch
queue-4.4/usb-serial-garmin_gps-fix-memory-leak-on-failed-urb-submit.patch
queue-4.4/usb-serial-io_ti-fix-null-deref-at-open.patch
queue-4.4/usb-serial-pl2303-fix-null-deref-at-open.patch
queue-4.4/usb-serial-quatech2-fix-sleep-while-atomic-in-close.patch
queue-4.4/usb-serial-iuu_phoenix-fix-null-deref-at-open.patch
queue-4.4/usb-serial-oti6858-fix-null-deref-at-open.patch
queue-4.4/usb-serial-io_edgeport-fix-null-deref-at-open.patch
queue-4.4/usb-serial-mos7720-fix-parport-use-after-free-on-probe-errors.patch
queue-4.4/usb-serial-mos7720-fix-use-after-free-on-probe-errors.patch
queue-4.4/usb-serial-mos7840-fix-null-deref-at-open.patch
queue-4.4/usb-serial-omninet-fix-null-derefs-at-open-and-disconnect.patch
queue-4.4/usb-serial-keyspan_pda-verify-endpoints-at-probe.patch
queue-4.4/usb-serial-io_ti-fix-another-null-deref-at-open.patch