CVE-2019-14821

Description

An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux kernels KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer struct kvm_coalesced_mmio 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.