6ad155377d
(generated with debian/scripts/import-upstream-tag) Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
39 lines
1.3 KiB
Diff
39 lines
1.3 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
|
|
Date: Fri, 31 Jan 2020 08:06:40 -0300
|
|
Subject: [PATCH] x86/kvm: Be careful not to clear KVM_VCPU_FLUSH_TLB bit
|
|
|
|
CVE-2019-3016
|
|
CVE-2020-3016
|
|
|
|
kvm_steal_time_set_preempted() may accidentally clear KVM_VCPU_FLUSH_TLB
|
|
bit if it is called more than once while VCPU is preempted.
|
|
|
|
This is part of CVE-2019-3016.
|
|
|
|
(This bug was also independently discovered by Jim Mattson
|
|
<jmattson@google.com>)
|
|
|
|
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
|
|
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
|
|
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
|
|
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
|
|
---
|
|
arch/x86/kvm/x86.c | 3 +++
|
|
1 file changed, 3 insertions(+)
|
|
|
|
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
|
|
index 9c45e6ca30fd..80e860bd39d5 100644
|
|
--- a/arch/x86/kvm/x86.c
|
|
+++ b/arch/x86/kvm/x86.c
|
|
@@ -3399,6 +3399,9 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
|
|
if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
|
|
return;
|
|
|
|
+ if (vcpu->arch.st.steal.preempted)
|
|
+ return;
|
|
+
|
|
vcpu->arch.st.steal.preempted = KVM_VCPU_PREEMPTED;
|
|
|
|
kvm_write_guest_offset_cached(vcpu->kvm, &vcpu->arch.st.stime,
|