linux-kernel - [PATCH v2 2/3] KVM: x86: force PDPTRs reload on SMM exit

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Mon, 23 Aug 2021 14:46:17 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Joerg Roedel <joro@...tes.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Jim Mattson <jmattson@...gle.com>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND
        64-BIT)), Wanpeng Li <wanpengli@...cent.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Borislav Petkov <bp@...en8.de>,
        Sean Christopherson <seanjc@...gle.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Ingo Molnar <mingo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>
Subject: [PATCH v2 2/3] KVM: x86: force PDPTRs reload on SMM exit

KVM_REQ_GET_NESTED_STATE_PAGES is also used with VM entries that happen
on exit from SMM mode, and in this case PDPTRS must be always reloaded.

Thanks to Sean Christopherson for pointing this out.

Fixes: 0f85722341b0 ("KVM: nVMX: delay loading of PDPTRs to KVM_REQ_GET_NESTED_STATE_PAGES")

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kvm/vmx/vmx.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index fada1055f325..4194fbf5e5d6 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7504,6 +7504,13 @@ static int vmx_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
 	}
 
 	if (vmx->nested.smm.guest_mode) {
+
+		/* Exit from the SMM to the non root mode also uses
+		 * the KVM_REQ_GET_NESTED_STATE_PAGES request,
+		 * but in this case the pdptrs must be always reloaded
+		 */
+		vcpu->arch.pdptrs_from_userspace = false;
+
 		ret = nested_vmx_enter_non_root_mode(vcpu, false);
 		if (ret)
 			return ret;
-- 
2.26.3