High
Canonical Ubuntu
Nick Peterson discovered that the Linux kernel did not properly handle debug exceptions following a MOV/POP to SS instruction. A local attacker could use this to cause a denial of service (system crash). This issue only affected the amd64 architecture. (CVE-2018-8897)
Andy Lutomirski discovered that the KVM subsystem of the Linux kernel did not properly emulate the ICEBP instruction following a MOV/POP to SS instruction. A local attacker in a KVM virtual machine could use this to cause a denial of service (guest VM crash) or possibly escalate privileges inside of the virtual machine. This issue only affected the i386 and amd64 architectures. (CVE-2018-1087)
Andy Lutomirski discovered that the Linux kernel did not properly perform error handling on virtualized debug registers. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-1000199)
Severity is high unless otherwise noted.
OSS users are strongly encouraged to follow one of the mitigations below: