USB: iowarrior: fix use-after-free after driver unbind

Make sure to stop also the asynchronous write URBs on disconnect() to
avoid use-after-free in the completion handler after driver unbind.

Fixes: 946b960d13c1 ("USB: add driver for iowarrior devices.")
Cc: stable <stable@vger.kernel.org>	# 2.6.21: 51a2f077c44e ("USB: introduce usb_anchor")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009104846.5925-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index 6841267..f405fa7 100644 (file)
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -87,6 +87,7 @@ struct iowarrior {
        char chip_serial[9];            /* the serial number string of the chip connected */
        int report_size;                /* number of bytes in a report */
        u16 product_id;
+       struct usb_anchor submitted;
 };
 
 /*--------------*/
@@ -425,11 +426,13 @@ static ssize_t iowarrior_write(struct file *file,
                        retval = -EFAULT;
                        goto error;
                }
+               usb_anchor_urb(int_out_urb, &dev->submitted);
                retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
                if (retval) {
                        dev_dbg(&dev->interface->dev,
                                "submit error %d for urb nr.%d\n",
                                retval, atomic_read(&dev->write_busy));
+                       usb_unanchor_urb(int_out_urb);
                        goto error;
                }
                /* submit was ok */
@@ -770,6 +773,8 @@ static int iowarrior_probe(struct usb_interface *interface,
        iface_desc = interface->cur_altsetting;
        dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 
+       init_usb_anchor(&dev->submitted);
+
        res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
        if (res) {
                dev_err(&interface->dev, "no interrupt-in endpoint found\n");
@@ -885,6 +890,7 @@ static void iowarrior_disconnect(struct usb_interface *interface)
                   Deleting the device is postponed until close() was called.
                 */
                usb_kill_urb(dev->int_in_urb);
+               usb_kill_anchored_urbs(&dev->submitted);
                wake_up_interruptible(&dev->read_wait);
                wake_up_interruptible(&dev->write_wait);
                mutex_unlock(&dev->mutex);