CVE-2020-11669

Se detectó un problema en el kernel de Linux versiones anteriores a 5.2, en la plataforma powerpc. El archivo arch/powerpc/kernel/idle_book3s.S no posee la funcionalidad de guardar y restaurar para PNV_POWERSAVE_AMR, PNV_POWERSAVE_UAMOR y PNV_POWERSAVE_AMOR, también se conoce como CID-53a712bae5dd.

A flaw was found in the way Linux kernel running on the Power9 processor saves and restores its registers while going in and coming out of an idle state. The issue occurs when a guest kernel has Kernel Userspace Address Protection (KUAP) feature enabled. The idle_book3s function does not save and restore the Authority Mask Register (AMR), Authority Mask Override Register (AMOR) and User Authority Mask Override Register (UAMOR). A guest user may use this flaw to render the host system unusable resulting in DoS issue.

It was discovered that the Serial CAN interface driver in the Linux kernel did not properly initialize data. A local attacker could use this to expose sensitive information. It was discovered that the linux kernel did not properly validate certain mount options to the tmpfs virtual memory file system. A local attacker with the ability to specify mount options could use this to cause a denial of service. Various other issues were also addressed.