diff --git a/mm/memory.c b/mm/memory.c
index 8e8c1832..5823698 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2648,6 +2648,7 @@
 		details.last_index = ULONG_MAX;
 	details.i_mmap_lock = &mapping->i_mmap_lock;
 
+	mutex_lock(&mapping->unmap_mutex);
 	spin_lock(&mapping->i_mmap_lock);
 
 	/* Protect against endless unmapping loops */
@@ -2664,6 +2665,7 @@
 	if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
 		unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
 	spin_unlock(&mapping->i_mmap_lock);
+	mutex_unlock(&mapping->unmap_mutex);
 }
 EXPORT_SYMBOL(unmap_mapping_range);