From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: [PATCH] KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221) Date: Thu, 7 Feb 2019 19:09:05 +0100 Message-ID: <1549562945-5503-3-git-send-email-pbonzini@redhat.com> Cc: Peter Shier , stable@kernel.org To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org From: Peter Shier Bugzilla: 1671904 There are multiple code paths where an hrtimer may have been started to emulate an L1 VMX preemption timer that can result in a call to free_nested without an intervening L2 exit where the hrtimer is normally cancelled. Unconditionally cancel in free_nested to cover all cases. Embargoed until Feb 7th 2019. Signed-off-by: Peter Shier Reported-by: Jim Mattson Reviewed-by: Jim Mattson Reported-by: Felix Wilhelm Cc: stable@kernel.org Message-Id: <20181011184646.154065-1-pshier@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 8ff20523661b..d8ea4ebd79e7 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -211,6 +211,7 @@ static void free_nested(struct kvm_vcpu *vcpu) if (!vmx->nested.vmxon && !vmx->nested.smm.vmxon) return; + hrtimer_cancel(&vmx->nested.preemption_timer); vmx->nested.vmxon = false; vmx->nested.smm.vmxon = false; free_vpid(vmx->nested.vpid02); -- 1.8.3.1