The driver may sleep in an interrupt handler. The function call path (from bottom to top) in Linux-4.17 is: [FUNC] fotg210_ep_queue(GFP_KERNEL) drivers/usb/gadget/udc/fotg210-udc.c, 744: fotg210_ep_queue in fotg210_get_status drivers/usb/gadget/udc/fotg210-udc.c, 768: fotg210_get_status in fotg210_setup_packet drivers/usb/gadget/udc/fotg210-udc.c, 949: fotg210_setup_packet in fotg210_irq (interrupt handler) To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC. If possible, spin_unlock() and spin_lock() around fotg210_ep_queue() can be also removed. This bug is found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> --- drivers/usb/gadget/udc/fotg210-udc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/udc/fotg210-udc.c b/drivers/usb/gadget/udc/fotg210-udc.c index 53a48f561458..c51510803d1f 100644 --- a/drivers/usb/gadget/udc/fotg210-udc.c +++ b/drivers/usb/gadget/udc/fotg210-udc.c @@ -741,7 +741,7 @@ static void fotg210_get_status(struct fotg210_udc *fotg210, fotg210->ep0_req->length = 2; spin_unlock(&fotg210->lock); - fotg210_ep_queue(fotg210->gadget.ep0, fotg210->ep0_req, GFP_KERNEL); + fotg210_ep_queue(fotg210->gadget.ep0, fotg210->ep0_req, GFP_ATOMIC); spin_lock(&fotg210->lock); } -- 2.17.0
