CVE-2018-8781

La función udl_fb_mmap en drivers/gpu/drm/udl/udl_fb.c en el kernel de Linux en su versión 3.4 y hasta e incluyendo la versión 4.15 tiene una vulnerabilidad de desbordamiento de enteros que permite que usuarios locales con acceso al controlador udldrmfb obtengan permisos totales de lectura y escritura en páginas físicas del kernel, lo que resulta en la ejecución de código en el espacio del kernel.

A an integer overflow vulnerability was discovered in the Linux kernel, from version 3.4 through 4.15, in the drivers/gpu/drm/udl/udl_fb.c:udl_fb_mmap() function. An attacker with access to the udldrmfb driver could exploit this to obtain full read and write permissions on kernel physical pages, resulting in a code execution in kernel space.

USN-3654-1 fixed vulnerabilities and added mitigations in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 LTS. 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. Various other issues were also addressed.