Ubuntu Security Notice 2701-1 – Andy Lutomirski discovered a flaw in the Linux kernel’s handling of nested NMIs (non-maskable interrupts). An unprivileged local user could exploit this flaw to cause a denial of service (system crash) or potentially escalate their privileges. Andy Lutomirski discovered a flaw that allows user to cause the Linux kernel to ignore some NMIs (non-maskable interrupts). A local unprivileged user could exploit this flaw to potentially cause the system to miss important NMIs resulting in unspecified effects. Various other issues were also addressed.