drivers/hid/hid-cp2112.c in the Linux kernel 4.9.x before 4.9.9 uses a spinlock without considering that sleeping is possible in a USB HID request callback, which allows local users to cause a denial of service (deadlock) via unspecified vectors. Upstream patch: https://github.com/torvalds/linux/commit/7a7b5df84b6b4e5d599c7289526eed96541a0654