On Thu, Sep 13, 2018 at 02:10:24PM -0700, Matthias Kaehlcke wrote:
From: Mathias Nyman mathias.nyman@linux.intel.com
commit 44a182b9d17765514fa2b1cc911e4e65134eef93 upstream.
KASAN found a use-after-free in xhci_free_virt_device+0x33b/0x38e where xhci_free_virt_device() sets slot id to 0 if udev exists: if (dev->udev && dev->udev->slot_id) dev->udev->slot_id = 0;
dev->udev will be true even if udev is freed because dev->udev is not set to NULL.
set dev->udev pointer to NULL in xhci_free_dev()
The original patch went to stable so this fix needs to be applied there as well.
Fixes: a400efe455f7 ("xhci: zero usb device slot_id member when disabling and freeing a xhci slot") Cc: stable@vger.kernel.org Reported-by: Guenter Roeck linux@roeck-us.net Reviewed-by: Guenter Roeck linux@roeck-us.net Tested-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Matthias Kaehlcke mka@chromium.org
The original fix has been integrated into some recent -stable versions, but wasn't backported to older LTS kernel like v4.9 or v4.4. The context in xhci_free_dev() changed a bit because upstream added xhci_disable_slot().
Now queued up, thanks.
greg k-h