diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 25a39052bf6b5653c3ab0317298864a2873fd911..9c6f3fd580597e5fdfcc5fc46031d9be0aaac74b 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -830,7 +830,7 @@ int __cpu_disable(void)
 
 	/* Update sibling maps */
 	base = cpu_first_thread_sibling(cpu);
-	for (i = 0; i < threads_per_core; i++) {
+	for (i = 0; i < threads_per_core && base + i < nr_cpu_ids; i++) {
 		cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
 		cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
 		cpumask_clear_cpu(cpu, cpu_core_mask(base + i));