[PATCH 4.19 071/103] KVM/nVMX: Do not validate that posted_intr_desc_addr is page aligned

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: KarimAllah Ahmed <karahmed@amazon.de>

commit 22a7cdcae6a4a3c8974899e62851d270956f58ce upstream.

The spec only requires the posted interrupt descriptor address to be
64-bytes aligned (i.e. bits[0:5] == 0). Using page_address_valid also
forces the address to be page aligned.

Only validate that the address does not cross the maximum physical address
without enforcing a page alignment.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Fixes: 6de84e581c0 ("nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2")
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Krish Sadhuhan <krish.sadhukhan@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
From: Mark Mielke <mark.mielke@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/vmx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11733,7 +11733,7 @@ static int nested_vmx_check_apicv_contro
 	    !nested_exit_intr_ack_set(vcpu) ||
 	    (vmcs12->posted_intr_nv & 0xff00) ||
 	    (vmcs12->posted_intr_desc_addr & 0x3f) ||
-	    (!page_address_valid(vcpu, vmcs12->posted_intr_desc_addr))))
+	    (vmcs12->posted_intr_desc_addr >> cpuid_maxphyaddr(vcpu))))
 		return -EINVAL;
 
 	/* tpr shadow is needed by all apicv features. */