CVE-2018-7757

Filtrado de memoria en la función sas_smp_get_phy_events en drivers/scsi/libsas/sas_expander.c en el kernel de Linux, hasta la versión 4.15.7, permite que usuarios locales provoquen una denegación de servicio (consumo de memoria) mediante numerosos accesos de lectura a archivos en el directorio /sys/class/sas_phy, tal y como demuestra el archivo /sys/class/sas_phy/phy-1:0:12/invalid_dword_count.

Memory leak in the sas_smp_get_phy_events function in drivers/scsi/libsas/sas_expander.c in the Linux kernel allows local users to cause a denial of service (kernel memory exhaustion) via multiple read accesses to files in the /sys/class/sas_phy directory.

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.