patch "USB: legousbtower: fix use-after-free on release" added to usb-linus

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

USB: legousbtower: fix use-after-free on release

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 726b55d0e22ca72c69c947af87785c830289ddbc Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Wed, 9 Oct 2019 17:38:47 +0200
Subject: USB: legousbtower: fix use-after-free on release

The driver was accessing its struct usb_device in its release() callback without holding a reference. This would lead to a use-after-free whenever the device was disconnected while the character device was still open.

---
 drivers/usb/misc/legousbtower.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

index 44d6a3381804..9d4c52a7ebe0 100644
@@ -296,6 +296,7 @@ static inline void tower_delete (struct lego_usb_tower *dev)
 	kfree (dev->read_buffer);
 	kfree (dev->interrupt_in_buffer);
 	kfree (dev->interrupt_out_buffer);
+	usb_put_dev(dev->udev);
 	kfree (dev);
 }
 

@@ -810,7 +811,7 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
 
 	mutex_init(&dev->lock);
 
-	dev->udev = udev;
+	dev->udev = usb_get_dev(udev);
 	dev->open_count = 0;
 	dev->disconnected = 0;
 

2.23.0