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Commit f36b507c authored by Jia-Ju Bai's avatar Jia-Ju Bai Committed by Felipe Balbi
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usb: gadget: r8a66597: Fix a possible sleep-in-atomic-context bugs in r8a66597_queue() 



The driver may sleep in an interrupt handler.
The function call path (from bottom to top) in Linux-4.16.7 is:

[FUNC] r8a66597_queue(GFP_KERNEL)
drivers/usb/gadget/udc/r8a66597-udc.c, 1193:
		r8a66597_queue in get_status
drivers/usb/gadget/udc/r8a66597-udc.c, 1301:
		get_status in setup_packet
drivers/usb/gadget/udc/r8a66597-udc.c, 1381:
		setup_packet in irq_control_stage
drivers/usb/gadget/udc/r8a66597-udc.c, 1508:
		irq_control_stage in r8a66597_irq (interrupt handler)

To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.

This bug is found by my static analysis tool (DSAC-2) and checked by
my code review.

Signed-off-by: default avatarJia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 0602088b

drivers/usb/gadget/udc/r8a66597-udc.c

+1 −1
Original line number Diff line number Diff line
@@ -1190,7 +1190,7 @@ __acquires(r8a66597->lock) 
	r8a66597->ep0_req->length = 2;

	/* AV: what happens if we get called again before that gets through? */

	spin_unlock(&r8a66597->lock);

	r8a66597_queue(r8a66597->gadget.ep0, r8a66597->ep0_req, GFP_KERNEL);

	r8a66597_queue(r8a66597->gadget.ep0, r8a66597->ep0_req, GFP_ATOMIC);

	spin_lock(&r8a66597->lock);

}