IB/mlx5: Fix data validation in mlx5_ib_alloc_ucontext

The wrong buffer size was passed to ib_is_udata_cleared.

Signed-off-by: Haggai Abramovsky <hagaya@mellanox.com>
Reviewed-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index f509dcb85665..f82336699c3e 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -845,6 +845,9 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
         if (!dev->ib_active)
                 return ERR_PTR(-EAGAIN);
 
+        if (udata->inlen < sizeof(struct ib_uverbs_cmd_hdr))
+                return ERR_PTR(-EINVAL);
+
         reqlen = udata->inlen - sizeof(struct ib_uverbs_cmd_hdr);
         if (reqlen == sizeof(struct mlx5_ib_alloc_ucontext_req))
                 ver = 0;
@@ -871,7 +874,7 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
 
         if (reqlen > sizeof(req) &&
             !ib_is_udata_cleared(udata, sizeof(req),
-                                 udata->inlen - sizeof(req)))
+                                 reqlen - sizeof(req)))
                 return ERR_PTR(-EOPNOTSUPP);
 
         req.total_num_uuars = ALIGN(req.total_num_uuars,