CVE-2018-8897 (https://nvd.nist.gov/vuln/detail/CVE-2018-8897): A flaw was found in the way the Linux kernel handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction after the stack switch is executed. An unprivileged system user could use this flaw to crash the system kernel resulting in the denial of service.
Upstream fix: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9
Fixed in >=sys-kernel/gentoo-sources-4.4.125, 4.4.128 is currently being stabilized in bug 653958 >=sys-kernel/gentoo-sources-4.9.91, 4.9.95 is currently being stabilized in bug 653956
Long been stabilized