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Commit 4efd805f authored by Radim Krčmář's avatar Radim Krčmář Committed by Paolo Bonzini
Browse files

KVM: x86: fix *NULL on invalid low-prio irq 



Smatch noticed a NULL dereference in kvm_intr_is_single_vcpu_fast that
happens if VM already warned about invalid lowest-priority interrupt.

Create a function for common code while fixing it.

Fixes: 6228a0da ("KVM: x86: Add lowest-priority support for vt-d posted-interrupts")
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 78db6a50

arch/x86/kvm/lapic.c

+13 −18
Original line number Diff line number Diff line
@@ -685,6 +685,15 @@ int kvm_vector_to_index(u32 vector, u32 dest_vcpus, 
	return idx;

}



static void kvm_apic_disabled_lapic_found(struct kvm *kvm)

{

	if (!kvm->arch.disabled_lapic_found) {

		kvm->arch.disabled_lapic_found = true;

		printk(KERN_INFO

		       "Disabled LAPIC found during irq injection\n");

	}

}



bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,

		struct kvm_lapic_irq *irq, int *r, unsigned long *dest_map)

{
@@ -763,15 +772,8 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, 
			idx = kvm_vector_to_index(irq->vector,

				dest_vcpus, &bitmap, 16);



			/*

			 * We may find a hardware disabled LAPIC here, if that

			 * is the case, print out a error message once for each

			 * guest and return.

			 */

			if (!dst[idx] && !kvm->arch.disabled_lapic_found) {

				kvm->arch.disabled_lapic_found = true;

				printk(KERN_INFO

					"Disabled LAPIC found during irq injection\n");

			if (!dst[idx]) {

				kvm_apic_disabled_lapic_found(kvm);

				goto out;

			}
@@ -859,16 +861,9 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq, 
			idx = kvm_vector_to_index(irq->vector, dest_vcpus,

						  &bitmap, 16);



			/*

			 * We may find a hardware disabled LAPIC here, if that

			 * is the case, print out a error message once for each

			 * guest and return

			 */

			dst = map->logical_map[cid][idx];

			if (!dst && !kvm->arch.disabled_lapic_found) {

				kvm->arch.disabled_lapic_found = true;

				printk(KERN_INFO

					"Disabled LAPIC found during irq injection\n");

			if (!dst) {

				kvm_apic_disabled_lapic_found(kvm);

				goto out;

			}