[PATCH 3.16 057/136] USB: iowarrior: fix use-after-free after driver unbind

Ben Hutchings
2019-12-17T00:58:51Z

From: Johan Hovold <johan@kernel.org>

commit b5f8d46867ca233d773408ffbe691a8062ed718f upstream.

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.")
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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/misc/iowarrior.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -89,6 +89,7 @@ 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;
};

/*--------------*/
@@ -437,11 +438,13 @@ static ssize_t iowarrior_write(struct fi
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 */
@@ -788,6 +791,8 @@ static int iowarrior_probe(struct usb_in
iface_desc = interface->cur_altsetting;
dev->product_id = le16_to_cpu(udev->descriptor.idProduct);

+ init_usb_anchor(&dev->submitted);
+
/* set up the endpoint information */
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
endpoint = &iface_desc->endpoint[i].desc;
@@ -917,6 +922,7 @@ static void iowarrior_disconnect(struct
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);