Re: [PATCH] net: randomize layout of struct net_device

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Jun 02, 2025 at 07:29:32PM +0530, Pranav Tyagi wrote:
> Add __randomize_layout to struct net_device to support structure layout
> randomization if CONFIG_RANDSTRUCT is enabled else the macro expands to
> do nothing. This enhances kernel protection by making it harder to
> predict the memory layout of this structure.
> 
> Link: https://github.com/KSPP/linux/issues/188
> Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
> ---
>  include/linux/netdevice.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 7ea022750e4e..0caff664ef3a 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -2077,7 +2077,11 @@ enum netdev_reg_state {
>   *	moves out.
>   */
>  
> +#ifdef CONFIG_RANDSTRUCT
> +struct __randomize_layout net_device {
> +#else
>  struct net_device {
> +#endif

Are you sure the #ifdef is needed?

thanks,

greg k-h