--- y/mm/mmap.c
+++ m/mm/mmap.c
@@ -674,6 +674,7 @@ int __vma_adjust(struct vm_area_struct *
 	int remove_next = 0;
 	MA_STATE(mas, &mm->mm_mt, 0, 0);
 	struct vm_area_struct *exporter = NULL, *importer = NULL;
+	bool valid_ptr = true;
 
 	if (next && !insert) {
 		if (end >= next->vm_end) {
@@ -760,6 +761,8 @@ again:
 	vma_adjust_trans_huge(orig_vma, start, end, adjust_next);
 
 	if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
+		if (!valid_ptr)
+			return -ENOMEM;
 		if (exporter && exporter->anon_vma)
 			unlink_anon_vmas(importer);
 		return -ENOMEM;
@@ -915,6 +918,7 @@ again:
 			mas_reset(&mas);
 			remove_next = 1;
 			end = next->vm_end;
+			valid_ptr = false;
 			goto again;
 		}
 	}