On Thu, Oct 04, 2018 at 02:33:53PM -0700, David Ahern wrote:
> From: David Ahern <dsah...@gmail.com>
>
> Update ip6addrlbl_dump for strict data checking. If the flag is set,
> the dump request is expected to have an ifaddrlblmsg struct as the
> header. All elements of the struct are expected to be 0 and no
> attributes can be appended.
>
> Signed-off-by: David Ahern <dsah...@gmail.com>
Acked-by: Christian Brauner <christ...@brauner.io>
> ---
> net/ipv6/addrlabel.c | 35 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
> index 1d6ced37ad71..10556049cc44 100644
> --- a/net/ipv6/addrlabel.c
> +++ b/net/ipv6/addrlabel.c
> @@ -458,20 +458,53 @@ static int ip6addrlbl_fill(struct sk_buff *skb,
> return 0;
> }
>
> +static int ip6addrlbl_valid_dump_req(const struct nlmsghdr *nlh,
> + struct netlink_ext_ack *extack)
> +{
> + struct ifaddrlblmsg *ifal;
> +
> + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifal))) {
> + NL_SET_ERR_MSG(extack, "Invalid header");
> + return -EINVAL;
> + }
> +
> + ifal = nlmsg_data(nlh);
> + if (ifal->__ifal_reserved || ifal->ifal_prefixlen ||
> + ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) {
> + NL_SET_ERR_MSG(extack,
> + "Invalid values in header for dump request");
> + return -EINVAL;
> + }
> +
> + if (nlh->nlmsg_len != nlmsg_msg_size(sizeof(*ifal))) {
> + NL_SET_ERR_MSG(extack, "Invalid data after header");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
> {
> + const struct nlmsghdr *nlh = cb->nlh;
> struct net *net = sock_net(skb->sk);
> struct ip6addrlbl_entry *p;
> int idx = 0, s_idx = cb->args[0];
> int err;
>
> + if (cb->strict_check) {
> + err = ip6addrlbl_valid_dump_req(nlh, cb->extack);
> + if (err)
> + return err;
> + }
> +
> rcu_read_lock();
> hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
> if (idx >= s_idx) {
> err = ip6addrlbl_fill(skb, p,
> net->ipv6.ip6addrlbl_table.seq,
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWADDRLABEL,
> NLM_F_MULTI);
> if (err < 0)
> --
> 2.11.0
>
