Re: [patch] IB/mlx5: stack info leak in mlx5_ib_alloc_ucontext()

Eli Cohen
2013-07-28T07:23:36Z

On Thu, Jul 25, 2013 at 08:04:36PM +0300, Dan Carpenter wrote:
> We don't set "resp.reserved". Since it's at the end of the struct that
> means we don't have to copy it to the user.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> index 8000fff..43dfb84 100644
> --- a/drivers/infiniband/hw/mlx5/main.c
> +++ b/drivers/infiniband/hw/mlx5/main.c
> @@ -619,7 +619,8 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
>
> resp.tot_uuars = req.total_num_uuars;
> resp.num_ports = dev->mdev.caps.num_ports;
> - err = ib_copy_to_udata(udata, &resp, sizeof(resp));
> + err = ib_copy_to_udata(udata, &resp,
> + sizeof(resp) - sizeof(resp.reserved));
> if (err)
> goto out_uars;
>

I don't have strong opinion on this one. The title of the patch is
stack info leak but the only leak of a reserved field. Other opinions?