From c8c6bd83bdb540466bef6a8ab89898e8e9ce2fd6 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 9 Feb 2017 12:11:41 +0100 Subject: [PATCH] USB: serial: mos7840: fix another NULL-deref at open commit 5182c2cf2a9bfb7f066ef0bdd2bb6330b94dd74e upstream. Fix another NULL-pointer dereference at open should a malicious device lack an interrupt-in endpoint. Note that the driver has a broken check for an interrupt-in endpoint which means that an interrupt URB has never even been submitted. Fixes: 3f5429746d91 ("USB: Moschip 7840 USB-Serial Driver") Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Willy Tarreau --- drivers/usb/serial/mos7840.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c index 5041b6c5b2d2..3308c43d2313 100644 --- a/drivers/usb/serial/mos7840.c +++ b/drivers/usb/serial/mos7840.c @@ -1041,6 +1041,7 @@ static int mos7840_open(struct tty_struct *tty, struct usb_serial_port *port) * (can't set it up in mos7840_startup as the structures * * were not set up at that time.) */ if (port0->open_ports == 1) { + /* FIXME: Buffer never NULL, so URB is not submitted. */ if (serial->port[0]->interrupt_in_buffer == NULL) { /* set up interrupt urb */ usb_fill_int_urb(serial->port[0]->interrupt_in_urb, @@ -2258,7 +2259,8 @@ static int mos7840_calc_num_ports(struct usb_serial *serial) static int mos7840_attach(struct usb_serial *serial) { if (serial->num_bulk_in < serial->num_ports || - serial->num_bulk_out < serial->num_ports) { + serial->num_bulk_out < serial->num_ports || + serial->num_interrupt_in < 1) { dev_err(&serial->interface->dev, "missing endpoints\n"); return -ENODEV; } -- 2.20.1