Race condition in fs/timerfd.c in the Linux kernel before 4.10.15 allows local users to gain privileges or cause a denial of service (list corruption or use-after-free) via simultaneous file-descriptor operations that leverage improper might_cancel queueing.
https://access.redhat.com/errata/RHSA-2018:3083
https://access.redhat.com/errata/RHSA-2018:3096
https://access.redhat.com/errata/RHSA-2019:4057
https://access.redhat.com/errata/RHSA-2019:4058
https://access.redhat.com/errata/RHSA-2020:0036
https://bugzilla.redhat.com/show_bug.cgi?id=1481136
https://github.com/torvalds/linux/commit/1e38da300e1e395a15048b0af1e5305bd91402f6
https://www.exploit-db.com/exploits/43345/
http://www.debian.org/security/2017/dsa-3981
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.10.15