diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 0e1632f75421..2048194a03be 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -283,7 +283,8 @@ static void swiotlb_init_io_tlb_pool(struct io_tlb_pool *mem, phys_addr_t start,
 	}
 
 	for (i = 0; i < mem->nslabs; i++) {
-		mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
+		mem->slots[i].list = min(IO_TLB_SEGSIZE - io_tlb_offset(i),
+					 mem->nslabs - i);
 		mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
 		mem->slots[i].alloc_size = 0;
 	}