On Thu, Oct 04, 2018 at 02:33:46PM -0700, David Ahern wrote:
> From: David Ahern <[email protected]>
>
> Update inet6_dump_ifinfo for strict data checking. If the flag is
> set, the dump request is expected to have an ifinfomsg 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 <[email protected]>
> ---
> net/ipv6/addrconf.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index f749a3ad721a..693199a29426 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -5628,6 +5628,31 @@ static int inet6_fill_ifinfo(struct sk_buff *skb,
> struct inet6_dev *idev,
> return -EMSGSIZE;
> }
>
> +static int inet6_valid_dump_ifinfo(const struct nlmsghdr *nlh,
> + struct netlink_ext_ack *extack)
> +{
> + struct ifinfomsg *ifm;
> +
> + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
> + NL_SET_ERR_MSG(extack, "Invalid header");
> + return -EINVAL;
> + }
> +
> + if (nlh->nlmsg_len > nlmsg_msg_size(sizeof(*ifm))) {
Shouldn't ipv6 specific dump requests at least support IFA_TARGET_NETNSID?
> + NL_SET_ERR_MSG(extack, "Invalid data after header");
> + return -EINVAL;
> + }
> +
> + ifm = nlmsg_data(nlh);
> + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
> + ifm->ifi_change || ifm->ifi_index) {
> + NL_SET_ERR_MSG(extack, "Invalid values in header for dump
> request");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback
> *cb)
> {
> struct net *net = sock_net(skb->sk);
> @@ -5637,6 +5662,16 @@ static int inet6_dump_ifinfo(struct sk_buff *skb,
> struct netlink_callback *cb)
> struct inet6_dev *idev;
> struct hlist_head *head;
>
> + /* only requests using strict checking can pass data to
> + * influence the dump
> + */
> + if (cb->strict_check) {
> + int err = inet6_valid_dump_ifinfo(cb->nlh, cb->extack);
> +
> + if (err)
> + return err;
> + }
> +
> s_h = cb->args[0];
> s_idx = cb->args[1];
>
> --
> 2.11.0
>
