4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jia-Ju Bai baijiaju1990@gmail.com
[ Upstream commit f36b507c14c4b6e634463a610294e9cb0065c8ea ]
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: Jia-Ju Bai baijiaju1990@gmail.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/udc/r8a66597-udc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/gadget/udc/r8a66597-udc.c +++ b/drivers/usb/gadget/udc/r8a66597-udc.c @@ -1193,7 +1193,7 @@ __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); }