4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> commit 6e22e3af7bb3a7b9dc53cb4687659f6e63fca427 upstream. wdm_in_callback() is a completion handler function for the USB driver. So it should not sleep. But it calls service_outstanding_interrupt(), which calls usb_submit_urb() with GFP_KERNEL. To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC. This bug is found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-wdm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -458,7 +458,7 @@ static int service_outstanding_interrupt set_bit(WDM_RESPONDING, &desc->flags); spin_unlock_irq(&desc->iuspin); - rv = usb_submit_urb(desc->response, GFP_KERNEL); + rv = usb_submit_urb(desc->response, GFP_ATOMIC); spin_lock_irq(&desc->iuspin); if (rv) { dev_err(&desc->intf->dev,