pve-edge-kernel/patches/kernel/0013-KVM-nVMX-unconditionally-cancel-preemption-timer-in-.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Shier <[email protected]>
Date: Mon, 25 Feb 2019 11:48:06 +0000
Subject: [PATCH] KVM: nVMX: unconditionally cancel preemption timer in
 free_nested (CVE-2019-7221)

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 <[email protected]>
Reported-by: Jim Mattson <[email protected]>
Reviewed-by: Jim Mattson <[email protected]>
Reported-by: Felix Wilhelm <[email protected]>
Cc: [email protected]
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

CVE-2019-7221

(backported from commit ecec76885bcfe3294685dc363fd1273df0d5d65f)
[tyhicks: Backport to 4.18:
 - free_nested() is in arch/x86/kvm/vmx.c]
Signed-off-by: Tyler Hicks <[email protected]>
Signed-off-by: Thomas Lamprecht <[email protected]>
---
 arch/x86/kvm/vmx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7ade6cb125d3..37b095e7f00a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7681,6 +7681,7 @@ static void free_nested(struct vcpu_vmx *vmx)
 	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);