Re: [PATCH v1 net-next] ipv6: Restore fib6_config validation for SIOCADDRT.

[David Ahern <dsahern@kernel.org>]

On 4/28/25 6:46 PM, Kuniyuki Iwashima wrote:
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index d0351e95d916..4c1e86e968f8 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -4496,6 +4496,53 @@ void rt6_purge_dflt_routers(struct net *net)
>  	rcu_read_unlock();
>  }
>  
> +static int fib6_config_validate(struct fib6_config *cfg,
> +				struct netlink_ext_ack *extack)
> +{
> +	/* RTF_PCPU is an internal flag; can not be set by userspace */
> +	if (cfg->fc_flags & RTF_PCPU) {
> +		NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
> +		goto errout;
> +	}
> +
> +	/* RTF_CACHE is an internal flag; can not be set by userspace */
> +	if (cfg->fc_flags & RTF_CACHE) {
> +		NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
> +		goto errout;
> +	}
> +
> +	if (cfg->fc_type > RTN_MAX) {
> +		NL_SET_ERR_MSG(extack, "Invalid route type");
> +		goto errout;
> +	}
> +
> +	if (cfg->fc_dst_len > 128) {
> +		NL_SET_ERR_MSG(extack, "Invalid prefix length");
> +		goto errout;
> +	}
> +
> +#ifdef CONFIG_IPV6_SUBTREES
> +	if (cfg->fc_src_len > 128) {
> +		NL_SET_ERR_MSG(extack, "Invalid source address length");
> +		goto errout;
> +	}
> +
> +	if (cfg->fc_nh_id &&  cfg->fc_src_len) {

extra space after '&&'



Reviewed-by: David Ahern <dsahern@kernel.org>