From: Jaesoo Lee <jalee@purestorage.com>
Date: Mon, 3 Jun 2019 16:42:28 -0700
Subject: nvme: Fix u32 overflow in the number of namespace list calculation
Patch-mainline: v5.2-rc4
Git-commit: c8e8c77b3bdbade6e26e8e76595f141ede12b692
References: git-fixes

The Number of Namespaces (nn) field in the identify controller data structure is
defined as u32 and the maximum allowed value in NVMe specification is
0xFFFFFFFEUL. This change fixes the possible overflow of the DIV_ROUND_UP()
operation used in nvme_scan_ns_list() by casting the nn to u64.

Signed-off-by: Jaesoo Lee <jalee@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/core.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3275,7 +3275,8 @@ static int nvme_scan_ns_list(struct nvme
 {
 	struct nvme_ns *ns;
 	__le32 *ns_list;
-	unsigned i, j, nsid, prev = 0, num_lists = DIV_ROUND_UP(nn, 1024);
+	unsigned i, j, nsid, prev = 0;
+	unsigned num_lists = DIV_ROUND_UP_ULL((u64)nn, 1024);
 	int ret = 0;
 
 	ns_list = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);