Patch "usbip: vudc: fix null pointer dereference on udc->lock" has been added to the 4.9-stable tree

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

    usbip: vudc: fix null pointer dereference on udc->lock

to the 4.9-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:
usbip-vudc-fix-null-pointer-dereference-on-udc-lock.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Colin Ian King <[email protected]>
Date: Thu, 22 Feb 2018 17:39:17 +0000
Subject: usbip: vudc: fix null pointer dereference on udc->lock

From: Colin Ian King <[email protected]>

commit df3334c223a033f562645712e832ca4cbb326bbf upstream.

Currently the driver attempts to spin lock on udc->lock before a NULL pointer check is performed on udc, hence there is a potential null pointer dereference on udc->lock. Fix this by moving the null check on udc before the lock occurs.

---
 drivers/usb/usbip/vudc_sysfs.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

@@ -117,10 +117,14 @@ static ssize_t store_sockfd(struct devic
 	if (rv != 0)
 		return -EINVAL;
 
+	if (!udc) {
+		dev_err(dev, "no device");
+		return -ENODEV;
+	}
 	spin_lock_irqsave(&udc->lock, flags);
 	/* Don't export what we don't have */
-	if (!udc || !udc->driver || !udc->pullup) {
-		dev_err(dev, "no device or gadget not bound");
+	if (!udc->driver || !udc->pullup) {
+		dev_err(dev, "gadget not bound");
 		ret = -ENODEV;
 		goto unlock;
 	}

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/mips-ath25-check-for-kzalloc-allocation-failure.patch queue-4.9/usbip-vudc-fix-null-pointer-dereference-on-udc-lock.patch queue-4.9/mips-octeon-irq-check-for-null-return-on-kzalloc-allocation.patch