--- zzzz-none-000/linux-4.4.60/mm/cma.c	2017-04-08 07:53:53.000000000 +0000
+++ scorpion-7490-727/linux-4.4.60/mm/cma.c	2021-02-04 17:41:59.000000000 +0000
@@ -385,6 +385,9 @@
 	bitmap_maxno = cma_bitmap_maxno(cma);
 	bitmap_count = cma_bitmap_pages_to_bits(cma, count);
 
+	if (bitmap_count > bitmap_maxno)
+		return NULL;
+
 	for (;;) {
 		mutex_lock(&cma->lock);
 		bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,