diff mbox series

[4/5] USB: legousbtower: fix use-after-free on release

Message ID 20191009153848.8664-5-johan@kernel.org (mailing list archive)
State Mainlined
Commit 726b55d0e22ca72c69c947af87785c830289ddbc
Headers show
Series USB: misc: fix disconnect bugs | expand

Commit Message

Johan Hovold Oct. 9, 2019, 3:38 p.m. UTC
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.

Fixes: fef526cae700 ("USB: legousbtower: remove custom debug macro")
Cc: stable <stable@vger.kernel.org>     # 3.12
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/misc/legousbtower.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 44d6a3381804..9d4c52a7ebe0 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -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;