Commit d77851bf authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

net: mpls: route: perform strict checks also for doit handlers 



Make RTM_GETROUTE's doit handler use strict checks when
NETLINK_F_STRICT_CHK is set.

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0eff0a27

net/mpls/af_mpls.c

+59 −2
Original line number Diff line number Diff line
@@ -2236,6 +2236,64 @@ static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 
		rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);

}



static int mpls_valid_getroute_req(struct sk_buff *skb,

				   const struct nlmsghdr *nlh,

				   struct nlattr **tb,

				   struct netlink_ext_ack *extack)

{

	struct rtmsg *rtm;

	int i, err;



	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {

		NL_SET_ERR_MSG_MOD(extack,

				   "Invalid header for get route request");

		return -EINVAL;

	}



	if (!netlink_strict_get_check(skb))

		return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,

				   rtm_mpls_policy, extack);



	rtm = nlmsg_data(nlh);

	if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||

	    rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||

	    rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {

		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");

		return -EINVAL;

	}

	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {

		NL_SET_ERR_MSG_MOD(extack,

				   "Invalid flags for get route request");

		return -EINVAL;

	}



	err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,

				 rtm_mpls_policy, extack);

	if (err)

		return err;



	if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {

		NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");

		return -EINVAL;

	}



	for (i = 0; i <= RTA_MAX; i++) {

		if (!tb[i])

			continue;



		switch (i) {

		case RTA_DST:

		case RTA_NEWDST:

			break;

		default:

			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");

			return -EINVAL;

		}

	}



	return 0;

}



static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,

			 struct netlink_ext_ack *extack)

{
@@ -2255,8 +2313,7 @@ static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 
	u8 n_labels;

	int err;



	err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX,

			  rtm_mpls_policy, extack);

	err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);

	if (err < 0)

		goto errout;