On Fri, Jul 17, 2020 at 12:05:09AM +0200, Andrew Lunn wrote:
> When the netlink interface code is disabled, a stub version of
> netlink_run_handler() is used. This stub version needs to handle the
> case when there is no possibility for a command to fall back to the
> IOCTL call. The two cable tests commands have no such fallback, and if
> we don't handle this, ethtool tries to jump through a NULL pointer
> resulting in a segfault.
> 
> Reported-by: Chris Healy <cphealy@gmail.com>
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>

Applied, thank you. I'll need to be more thorough with teseting the
--disable-netlink builds.

Michal

> ---
>  netlink/extapi.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/netlink/extapi.h b/netlink/extapi.h
> index c5bfde9..a35d5f2 100644
> --- a/netlink/extapi.h
> +++ b/netlink/extapi.h
> @@ -46,6 +46,12 @@ void nl_monitor_usage(void);
>  static inline void netlink_run_handler(struct cmd_context *ctx,
>  				       nl_func_t nlfunc, bool no_fallback)
>  {
> +	if (no_fallback) {
> +		fprintf(stderr,
> +			"Command requires kernel netlink support which is not "
> +			"enabled in this ethtool binary\n");
> +		exit(1);
> +	}
>  }
>  
>  static inline int nl_monitor(struct cmd_context *ctx)
> -- 
> 2.27.0
>