nvme: Fix parsing of ANA log page

Check validity of offset into ANA log buffer before accessing
nvme_ana_group_desc. This check ensures the size of ANA log buffer >=
offset + sizeof(nvme_ana_group_desc)

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Prabhath Sajeepa <psajeepa@purestorage.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 103c04fa7746f010d4c880250ccf5c97c6195440..682be6195a9518f248c36abeeb850b8c30c4c9d9 100644 (file)
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -445,8 +445,14 @@ static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data,
 
        for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) {
                struct nvme_ana_group_desc *desc = base + offset;
-               u32 nr_nsids = le32_to_cpu(desc->nnsids);
-               size_t nsid_buf_size = nr_nsids * sizeof(__le32);
+               u32 nr_nsids;
+               size_t nsid_buf_size;
+
+               if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc)))
+                       return -EINVAL;
+
+               nr_nsids = le32_to_cpu(desc->nnsids);
+               nsid_buf_size = nr_nsids * sizeof(__le32);
 
                if (WARN_ON_ONCE(desc->grpid == 0))
                        return -EINVAL;
@@ -466,8 +472,6 @@ static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data,
                        return error;
 
                offset += nsid_buf_size;
-               if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc)))
-                       return -EINVAL;
        }
 
        return 0;