The futex_requeue function in kernel/futex.c in the Linux kernel before 4.14.15 might allow attackers to cause a denial of service (integer overflow) or possibly have unspecified other impact by triggering a negative wake or requeue value.
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.15
https://www.debian.org/security/2018/dsa-4187
https://usn.ubuntu.com/3698-2/
https://usn.ubuntu.com/3698-1/
https://usn.ubuntu.com/3697-2/
https://usn.ubuntu.com/3697-1/
https://usn.ubuntu.com/3619-2/
https://usn.ubuntu.com/3619-1/
https://lists.debian.org/debian-lts-announce/2018/05/msg00000.html
https://github.com/torvalds/linux/commit/fbe0e839d1e22d88810f3ee3e2f1479be4c0aa4a
https://access.redhat.com/errata/RHSA-2018:1062
https://access.redhat.com/errata/RHSA-2018:0676
https://access.redhat.com/errata/RHSA-2018:0654