Re: [net-next] tipc: fix uninit-value in tipc_nl_node_reset_link_stats

[Jakub Kicinski <kuba@kernel.org>]

On Tue,  5 Jul 2022 07:50:57 +0700 Hoang Le wrote:
> Reported-by: syzbot+a73d24a22eeeebe5f244@syzkaller.appspotmail.com
> Acked-by: Jon Maloy <jmaloy@redhat.com>
> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>

Can we get a Fixes tag please?

> diff --git a/net/tipc/node.c b/net/tipc/node.c
> index b48d97cbbe29..23419a599471 100644
> --- a/net/tipc/node.c
> +++ b/net/tipc/node.c
> @@ -2561,6 +2561,7 @@ int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
>  	struct net *net = sock_net(skb->sk);
>  	struct tipc_net *tn = tipc_net(net);
>  	struct tipc_link_entry *le;
> +	int len;
>  
>  	if (!info->attrs[TIPC_NLA_LINK])
>  		return -EINVAL;
> @@ -2574,7 +2575,14 @@ int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
>  	if (!attrs[TIPC_NLA_LINK_NAME])
>  		return -EINVAL;
>  
> +	len = nla_len(attrs[TIPC_NLA_LINK_NAME]);
> +	if (len <= 0)
> +		return -EINVAL;
> +
>  	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
> +	len = min_t(int, len, TIPC_MAX_LINK_NAME);
> +	if (!memchr(link_name, '\0', len))
> +		return -EINVAL;

Should we just change the netlink policy for this attribute to
NLA_NUL_STRING, then?