diff --git a/mm/cma.c b/mm/cma.c
index eaa4b5c920a2..4a978e09547a 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -37,6 +37,7 @@
 
 struct cma cma_areas[MAX_CMA_AREAS];
 unsigned cma_area_count;
+static DEFINE_MUTEX(cma_mutex);
 
 phys_addr_t cma_get_base(const struct cma *cma)
 {
@@ -468,9 +469,10 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
 		spin_unlock_irq(&cma->lock);
 
 		pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
+		mutex_lock(&cma_mutex);
 		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
 				     GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
-
+		mutex_unlock(&cma_mutex);
 		if (ret == 0) {
 			page = pfn_to_page(pfn);
 			break;