From 726b55d0e22ca72c69c947af87785c830289ddbc Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 9 Oct 2019 17:38:47 +0200 Subject: [PATCH] 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. Fixes: fef526cae700 ("USB: legousbtower: remove custom debug macro") Cc: stable # 3.12 Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20191009153848.8664-5-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/legousbtower.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c index 44d6a33..9d4c52a 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; -- 2.7.4