diff --git a/arch/powerpc/mm/mmu_context_64.c b/arch/powerpc/mm/mmu_context_64.c
index 65d18dca266ff0e3b26ed1212ca3da5990ee150c..e2051efa09c58d413d95814615c94f2d683b8b22 100644
--- a/arch/powerpc/mm/mmu_context_64.c
+++ b/arch/powerpc/mm/mmu_context_64.c
@@ -44,7 +44,9 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 		return err;
 
 	if (index > MAX_CONTEXT) {
+		spin_lock(&mmu_context_lock);
 		idr_remove(&mmu_context_idr, index);
+		spin_unlock(&mmu_context_lock);
 		return -ENOMEM;
 	}