nvme: Fix u32 overflow in the number of namespace list calculation

[ Upstream commit c8e8c77b3bdbade6e26e8e76595f141ede12b692 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 35d2202ee2fd1b0c055e802504a4f5aca936e215..3a390b2c754022230a4eee475b6af2b548cd1286 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3397,7 +3397,8 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn)
 {
        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);