[PATCH v2 4/4] KVM: arm64: vgic-v4: Restore nr_vpes before freeing the vPE resources

[Fuad Tabba]

vgic_v4_init() truncates its_vm.nr_vpes to the failing index to bound
vgic_v4_teardown()'s free_irq() loop, but its_free_vcpu_irqs() reads
the same field: the vPE irqs and the v4.1 SGI domains at or above that
index are never freed, each one leaking a vpe_id and an LPI pending
table.

Restore the count from online_vcpus before that call. This depends on
the previous patch: a failed vgic_init() keeps admitting vCPUs, so
without that patch's teardown the vPE array outlives the failure while
online_vcpus grows past the size it was allocated with.

Fixes: bdb2d2ccac65 ("KVM: arm/arm64: GICv4: Add doorbell interrupt handling")
Reported-by: Sashiko <sashiko-bot at kernel.org>
Closes: https://lore.kernel.org/all/20260820130616.1A7241F000E9@smtp.kernel.org/
Suggested-by: Marc Zyngier <maz at kernel.org>
Signed-off-by: Fuad Tabba <fuad.tabba at linux.dev>
---
 arch/arm64/kvm/vgic/vgic-v4.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
index ed236f083f0d7..30e1de3fc7d9d 100644
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -333,6 +333,9 @@ void vgic_v4_teardown(struct kvm *kvm)
 		free_irq(irq, vcpu);
 	}
 
+	/* Make sure we free all VM-wide, per-CPU resources */
+	its_vm->nr_vpes = atomic_read(&kvm->online_vcpus);
+
 	its_free_vcpu_irqs(its_vm);
 	kfree(its_vm->vpes);
 	its_vm->nr_vpes = 0;
-- 
2.39.5