Commit ba5838ab authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: x86: Inject #GP if WRMSR sets reserved bits in APIC Self-IPI 



Inject a #GP if the guest attempts to set reserved bits in the x2APIC-only
Self-IPI register.  Bits 7:0 hold the vector, all other bits are reserved.

Reported-by: default avatarMarc Orr <marcorr@google.com>
Cc: Ben Gardon <bgardon@google.com>
Cc: Venkatesh Srinivas <venkateshs@chromium.org>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20230107011025.565472-2-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 85e64d09

arch/x86/kvm/lapic.c

+7 −3
Original line number Diff line number Diff line
@@ -2324,10 +2324,14 @@ static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) 
		break;



	case APIC_SELF_IPI:

		if (apic_x2apic_mode(apic))

			kvm_apic_send_ipi(apic, APIC_DEST_SELF | (val & APIC_VECTOR_MASK), 0);

		else

		/*

		 * Self-IPI exists only when x2APIC is enabled.  Bits 7:0 hold

		 * the vector, everything else is reserved.

		 */

		if (!apic_x2apic_mode(apic) || (val & ~APIC_VECTOR_MASK))

			ret = 1;

		else

			kvm_apic_send_ipi(apic, APIC_DEST_SELF | val, 0);

		break;

	default:

		ret = 1;