usb: gadget: r8a66597: Fix a possible sleep-in-atomic-context bugs in r8a66597_queue()
authorJia-Ju Bai <baijiaju1990@gmail.com>
Wed, 20 Jun 2018 03:55:08 +0000 (11:55 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 5 Sep 2018 07:26:26 +0000 (09:26 +0200)
commit43b058dc21cdb8908d01e526a5bb1875ec00bd81
tree94ea27be921106fd1ea1cbc00f156046cf92f115
parent3f41c2d0e61859cef7a9bd91d3f2ca81c7955fda
usb: gadget: r8a66597: Fix a possible sleep-in-atomic-context bugs in r8a66597_queue()

[ 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