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: v5.2.3~88
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1d83b4652e023a0bb86e1689882e46fc28f2184a;p=users%2Fdwmw2%2Flinux.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 46af3a5e92094..726e3f8d65a08 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2878,9 +2878,6 @@ 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();
 		}
 	}