CVE-2017-18208

La función madvise_willneed en mm/madvise.c en el kernel de Linux, en versiones anteriores a la 4.14.4, permite que usuarios locales provoquen una denegación de servicio (bucle infinito) desencadenando el uso de MADVISE_WILLNEED para un mapeo DAX.

The madvise_willneed function in the Linux kernel allows local users to cause a denial of service (infinite loop) by triggering use of MADVISE_WILLNEED for a DAX mapping.

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.