kernel: KVM: nVMX: missing IBPB when exiting from nested guest can lead to Spectre v2 attacks

A flaw was found in the KVM's Intel nested virtualization feature nVMX. Since L1 and L2 shared branch prediction modes guest-user and guest-kernel, KVM did not protect indirect branches in L1 from steering by a malicious agent in L2. This could allow a malicious nested guest to carry out Spectre ...

LSN-0081-1: Kernel Live Patch Security Notice

Maxim Levitsky discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not properly prevent a guest VM from enabling AVIC in nested guest VMs. An attacker in a guest VM could use this to write to portions of the host's physical memory.CVE-2021-3653 Maxim...

USN-5072-1: Linux kernel vulnerabilities

Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel allowed a guest VM to disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a guest VM could use this to read or write portions of the host's physical memory...

USN-4300-1: Linux kernel vulnerabilities

It was discovered that the KVM implementation in the Linux kernel, when paravirtual TLB flushes are enabled in guests, the hypervisor in some situations could miss deferred TLB flushes or otherwise mishandle them. An attacker in a guest VM could use this to expose sensitive information read memor...

USN-4303-1 linux, linux-aws, linux-kvm vulnerability

Paulo Bonzini discovered that the KVM hypervisor implementation in the Linux kernel could improperly let a nested level 2 guest access the resources of a parent level 1 guest in certain situations. An attacker could use this to expose sensitive information...

USN-4303-2 linux-lts-xenial, linux-aws vulnerability

USN-4303-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement HWE kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 ESM. Paulo Bonzini discovered that the KVM hypervisor implementation in the Linux kernel...

USN-4303-2: Linux kernel (HWE) vulnerability

USN-4303-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement HWE kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 ESM. Paulo Bonzini discovered that the KVM hypervisor implementation in the Linux kernel...

Ubuntu: Security Advisory (USN-4301-1)

The remote host is missing an update for the SPDX-FileCopyrightText: 2020 Greenbone AG Some text descriptions might be excerpted from a referenced sources, and are Copyright C by the respective right holders. SPDX-License-Identifier: GPL-2.0-only ifdescription...

Ubuntu: Security Advisory (USN-4303-1)

The remote host is missing an update for the SPDX-FileCopyrightText: 2020 Greenbone AG Some text descriptions might be excerpted from a referenced sources, and are Copyright C by the respective right holders. SPDX-License-Identifier: GPL-2.0-only ifdescription...