diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index add45eb9ea97..3184f03605a3 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -212,7 +212,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 		mm = alloc->vma_vm_mm;
 
 	if (mm) {
-		down_read(&mm->mmap_sem);
+		down_write(&mm->mmap_sem);
 		vma = alloc->vma;
 	}
 
@@ -271,7 +271,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 		/* vm_insert_page does not seem to increment the refcount */
 	}
 	if (mm) {
-		up_read(&mm->mmap_sem);
+		up_write(&mm->mmap_sem);
 		mmput(mm);
 	}
 	return 0;
@@ -304,7 +304,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 	}
 err_no_vma:
 	if (mm) {
-		up_read(&mm->mmap_sem);
+		up_write(&mm->mmap_sem);
 		mmput(mm);
 	}
 	return vma ? -ENOMEM : -ESRCH;