CVE-2017-7889

El subsistema mm en el kernel de Linux hasta la versión 3.2 no aplica adecuadamente el mecanismo de protección CONFIG_STRICT_DEVMEM, lo que permite a usuarios locales leer o escribir en ubicaciones de la memoria del kernel en el primer megabyte (y eludir restricciones de acceso de asignación de slab) a través de una aplicación que abre el archivo /dev/mem, relacionado con arch/x86/mm/init.c y drivers/char/mem.c

The mm subsystem in the Linux kernel through 4.10.10 does not properly enforce the CONFIG_STRICT_DEVMEM protection mechanism, which allows local users to read or write to kernel memory locations in the first megabyte (and bypass slab-allocation access restrictions) via an application that opens the /dev/mem file, related to arch/x86/mm/init.c and drivers/char/mem.c.

USN-3358-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.04. This update provides the corresponding updates for the Linux Hardware Enablement kernel from Ubuntu 17.04 for Ubuntu 16.04 LTS. Please note that this update changes the Linux HWE kernel to the 4.10 based kernel from Ubuntu 17.04, superseding the 4.8 based HWE kernel from Ubuntu 16.10. Ben Harris discovered that the Linux kernel would strip extended privilege attributes of files when performing a failed unprivileged system call. A local attacker could use this to cause a denial of service. Various other issues were also addressed.