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 a867a139bb35a9d238de2042d96dc91028e0e52a..d8869d978c341474051a1f21981aca9f859cf3bc 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3228,7 +3228,8 @@ 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);