The hashbin_delete function in net/irda/irqueue.c in the Linux kernel before 4.9.13 improperly manages lock dropping, which allows local users to cause a denial of service (deadlock) via crafted operations on IrDA devices.
https://usn.ubuntu.com/3754-1/
https://github.com/torvalds/linux/commit/4c03b862b12f980456f9de92db6d508a4999b788
http://www.securityfocus.com/bid/96483
http://www.openwall.com/lists/oss-security/2017/02/28/4
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.13