| From ecec76885bcfe3294685dc363fd1273df0d5d65f Mon Sep 17 00:00:00 2001 |
| From: Peter Shier <pshier@google.com> |
| Date: Thu, 11 Oct 2018 11:46:46 -0700 |
| Subject: KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221) |
| |
| 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); |
