CVE-2018-1087

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 4.16 Linux kernel versions 4.16-rc7 and earlier Linux kernel versions 4.17-rc1 through 4.17-rc3

Description The issue is related to a flaw in the way the Linux kernel's KVM hypervisor handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction after the stack switch is executed. An unprivileged KVM guest user could use this flaw to crash the guest or, potentially, escalate their privileges in the guest.

Recommendations For Linux kernel versions prior to 4.16, update to version 4.16 or later. For Linux kernel versions 4.16-rc7 and earlier, update to a version later than 4.16-rc7. For Linux kernel versions 4.17-rc1 through 4.17-rc3, update to a version later than 4.17-rc3. As a temporary workaround, consider restricting access to the KVM hypervisor to minimize the risk of exploitation.