IB/mlx4: Potential buffer overflow in _mlx4_set_path()

Smatch complains about this code:

    drivers/infiniband/hw/mlx4/qp.c:1827 _mlx4_set_path()
    error: buffer overflow 'dev->dev->caps.gid_table_len' 3 <= 255

The mlx4_ib_gid_index_to_real_index() does check that "port" is within
bounds, but we don't check the return value for errors.  It seems simple
enough to add a check for that.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index 013049bcdb53d5fb95ca61d1ab9640aaa62b0756..817257f105aadbcfca450a1bc2b9582e01185b7a 100644 (file)
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -1824,6 +1824,8 @@ static int _mlx4_set_path(struct mlx4_ib_dev *dev,
                        mlx4_ib_gid_index_to_real_index(dev, port,
                                                        grh->sgid_index);
 
+               if (real_sgid_index < 0)
+                       return real_sgid_index;
                if (real_sgid_index >= dev->dev->caps.gid_table_len[port]) {
                        pr_err("sgid_index (%u) too large. max is %d\n",
                               real_sgid_index, dev->dev->caps.gid_table_len[port] - 1);