linux-kernel - [PATCH 5.14 060/172] KVM: nVMX: Fix nested bus lock VM 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,  4 Oct 2021 14:51:50 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Chenyi Qiang <chenyi.qiang@...el.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Xiaoyao Li <xiaoyao.li@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 5.14 060/172] KVM: nVMX: Fix nested bus lock VM exit

From: Chenyi Qiang <chenyi.qiang@...el.com>

commit 24a996ade34d00deef5dee2c33aacd8fda91ec31 upstream.

Nested bus lock VM exits are not supported yet. If L2 triggers bus lock
VM exit, it will be directed to L1 VMM, which would cause unexpected
behavior. Therefore, handle L2's bus lock VM exits in L0 directly.

Fixes: fe6b6bc802b4 ("KVM: VMX: Enable bus lock VM exit")
Signed-off-by: Chenyi Qiang <chenyi.qiang@...el.com>
Reviewed-by: Sean Christopherson <seanjc@...gle.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@...el.com>
Message-Id: <20210914095041.29764-1-chenyi.qiang@...el.com>
Cc: stable@...r.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/x86/kvm/vmx/nested.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5898,6 +5898,12 @@ static bool nested_vmx_l0_wants_exit(str
 	case EXIT_REASON_VMFUNC:
 		/* VM functions are emulated through L2->L0 vmexits. */
 		return true;
+	case EXIT_REASON_BUS_LOCK:
+		/*
+		 * At present, bus lock VM exit is never exposed to L1.
+		 * Handle L2's bus locks in L0 directly.
+		 */
+		return true;
 	default:
 		break;
 	}