| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.20 341/352] KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221) | Date | Mon, 11 Feb 2019 15:19:28 +0100 |
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4.20-stable review patch. If anyone has any objections, please let me know.
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From: Peter Shier <pshier@google.com>
commit ecec76885bcfe3294685dc363fd1273df0d5d65f upstream.
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 <pshier@google.com> Reported-by: Jim Mattson <jmattson@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reported-by: Felix Wilhelm <fwilhelm@google.com> Cc: stable@kernel.org Message-Id: <20181011184646.154065-1-pshier@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/kvm/vmx.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8509,6 +8509,7 @@ static void free_nested(struct kvm_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);
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