IB/mlx5: Fix out-of-bound access

commit 0fd27a88c2e4f548937fd7d93fc6e65c4ad7c278 upstream.

When we initialize buffer to create SRQ in kernel,
the number of pages was less than actually used in
following mlx5_fill_page_array().

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 8 deletions

diff --git a/drivers/infiniband/hw/mlx5/srq.c b/drivers/infiniband/hw/mlx5/srq.c
index 729b0696626e..d61fd2c727c0 100644
--- a/drivers/infiniband/hw/mlx5/srq.c
+++ b/drivers/infiniband/hw/mlx5/srq.c
@@ -165,8 +165,6 @@ static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
         int err;
         int i;
         struct mlx5_wqe_srq_next_seg *next;
-        int page_shift;
-        int npages;
 
         err = mlx5_db_alloc(dev->mdev, &srq->db);
         if (err) {
@@ -179,7 +177,6 @@ static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
                 err = -ENOMEM;
                 goto err_db;
         }
-        page_shift = srq->buf.page_shift;
 
         srq->head    = 0;
         srq->tail    = srq->msrq.max - 1;
@@ -191,10 +188,8 @@ static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
                         cpu_to_be16((i + 1) & (srq->msrq.max - 1));
         }
 
-        npages = DIV_ROUND_UP(srq->buf.npages, 1 << (page_shift - PAGE_SHIFT));
-        mlx5_ib_dbg(dev, "buf_size %d, page_shift %d, npages %d, calc npages %d\n",
-                    buf_size, page_shift, srq->buf.npages, npages);
-        in->pas = mlx5_vzalloc(sizeof(*in->pas) * npages);
+        mlx5_ib_dbg(dev, "srq->buf.page_shift = %d\n", srq->buf.page_shift);
+        in->pas = mlx5_vzalloc(sizeof(*in->pas) * srq->buf.npages);
         if (!in->pas) {
                 err = -ENOMEM;
                 goto err_buf;
@@ -210,7 +205,7 @@ static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
         }
         srq->wq_sig = !!srq_signature;
 
-        in->log_page_size = page_shift - MLX5_ADAPTER_PAGE_SHIFT;
+        in->log_page_size = srq->buf.page_shift - MLX5_ADAPTER_PAGE_SHIFT;
         if (MLX5_CAP_GEN(dev->mdev, cqe_version) == MLX5_CQE_VERSION_V1 &&
             in->type == IB_SRQT_XRC)
                 in->user_index = MLX5_IB_DEFAULT_UIDX;