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 --- drivers/usb/host/xhci.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 9b27798..711da33 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3621,6 +3621,7 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev) del_timer_sync(&virt_dev->eps[i].stop_cmd_timer); } xhci_debugfs_remove_slot(xhci, udev->slot_id); + virt_dev->udev = NULL; ret = xhci_disable_slot(xhci, udev->slot_id); if (ret) xhci_free_virt_device(xhci, udev->slot_id);