linux-kernel - [PATCH stable-4.19 2/2] KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190725104645.30642-3-vkuznets@redhat.com>
Date:   Thu, 25 Jul 2019 12:46:45 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     stable@...r.kernel.org
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>
Subject: [PATCH stable-4.19 2/2] KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested

From: Jan Kiszka <jan.kiszka@...mens.com>

[ Upstream commit cf64527bb33f6cec2ed50f89182fc4688d0056b6 ]

Letting this pend may cause nested_get_vmcs12_pages to run against an
invalid state, corrupting the effective vmcs of L1.

This was triggerable in QEMU after a guest corruption in L2, followed by
a L1 reset.

Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
Reviewed-by: Liran Alon <liran.alon@...cle.com>
Cc: stable@...r.kernel.org
Fixes: 7f7f1ba33cf2 ("KVM: x86: do not load vmcs12 pages while still in SMM")
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/vmx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 880bc36a0d5d..4cf16378dffe 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8490,6 +8490,8 @@ static void free_nested(struct vcpu_vmx *vmx)
 	if (!vmx->nested.vmxon && !vmx->nested.smm.vmxon)
 		return;
 
+	kvm_clear_request(KVM_REQ_GET_VMCS12_PAGES, &vmx->vcpu);
+
 	hrtimer_cancel(&vmx->nested.preemption_timer);
 	vmx->nested.vmxon = false;
 	vmx->nested.smm.vmxon = false;
-- 
2.20.1