From: Sean Christopherson <sean.j.christopherson@intel.com>
Date: Tue, 7 May 2019 16:06:26 +0000 (-0700)
Subject: KVM: nVMX: Don't dump VMCS if virtual APIC page can't be mapped
X-Git-Tag: v5.1.20~73
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ff7d3d1986f7c8ae88b943f43d46f1362ac8d07;p=thirdparty%2Fkernel%2Fstable.git

KVM: nVMX: Don't dump VMCS if virtual APIC page can't be mapped

commit 73cb85568433feadb79e963bf2efba9b3e9ae3df upstream.

... as a malicious userspace can run a toy guest to generate invalid
virtual-APIC page addresses in L1, i.e. flood the kernel log with error
messages.

Fixes: 690908104e39d ("KVM: nVMX: allow tests to use bad virtual-APIC page address")
Cc: stable@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 4ca834d221691..dffada006af25 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2891,9 +2891,6 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
 			 */
 			vmcs_clear_bits(CPU_BASED_VM_EXEC_CONTROL,
 					CPU_BASED_TPR_SHADOW);
-		} else {
-			printk("bad virtual-APIC page address\n");
-			dump_vmcs();
 		}
 	}