CVE-2017-18221

La función __munlock_pagevec en mm/mlock.c en el kernel de Linux, en versiones anteriores a la 4.11.4, permite que usuarios locales provoquen una denegación de servicio (corrupción de contabilidad NR_MLOCK) mediante el uso manipulado de llamadas del sistema mlockall y munlockall.

Jann Horn and Ken Johnson discovered that microprocessors utilizing speculative execution of a memory read may allow unauthorized memory reads via a sidechannel attack. This flaw is known as Spectre Variant 4. A local attacker could use this to expose sensitive information, including kernel memory. Jan H. Schonherr discovered that the Xen subsystem did not properly handle block IO merges correctly in some situations. An attacker in a guest vm could use this to cause a denial of service or possibly gain administrative privileges in the host. Various other issues were also addressed.