CVE-2019-14821: High severity Linux Linux kernel vulnerability

An out-of-bounds access issue was found in the way Linux kernel's KVM hypervisor implements Coalesced MMIO write operation. It operates on a MMIO ring buffer 'struct kvmcoalescedmmio' object, wherein write indices 'ring->first' and 'ring->last' value could be supplied by a host user-space process.

An unprivileged host user/process with access to '/dev/kvm' device could use this flaw to crash the host kernel resulting in DoS OR potentially escalate privileges on the system.

Upstream patch: --------------- -> https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=b60fe990c6b07ef6d4df67bc0530c7c90a62623a

Reference: ---------- -> https://www.openwall.com/lists/oss-security/2019/09/20/1

— Red Hat

An out-of-bounds access issue was found in the way Linux kernel's KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer 'struct kvmcoalescedmmio' object, wherein write indices 'ring->first' and 'ring->last' value could be supplied by a host user-space process. An unprivileged host user or process with access to '/dev/kvm' device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system.