On Thu, Sep 13, 2018 at 02:10:24PM -0700, Matthias Kaehlcke wrote: > From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> > > 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@xxxxxxxxxxxxxxx> > Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> > --- > 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