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Commit d0440029 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

net: ipv4: ipmr: perform strict checks also for doit handlers 



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

v2: - improve extack messages (DaveA).

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a00302b6

net/ipv4/ipmr.c

+56 −5
Original line number Diff line number Diff line
@@ -2467,6 +2467,61 @@ static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt) 
	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);

}



static int ipmr_rtm_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(extack, "ipv4: Invalid header for multicast route get request");

		return -EINVAL;

	}



	if (!netlink_strict_get_check(skb))

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

				   rtm_ipv4_policy, extack);



	rtm = nlmsg_data(nlh);

	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||

	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||

	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||

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

		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");

		return -EINVAL;

	}



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

				 rtm_ipv4_policy, extack);

	if (err)

		return err;



	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||

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

		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");

		return -EINVAL;

	}



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

		if (!tb[i])

			continue;



		switch (i) {

		case RTA_SRC:

		case RTA_DST:

		case RTA_TABLE:

			break;

		default:

			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");

			return -EINVAL;

		}

	}



	return 0;

}



static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,

			     struct netlink_ext_ack *extack)

{
@@ -2475,18 +2530,14 @@ static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 
	struct sk_buff *skb = NULL;

	struct mfc_cache *cache;

	struct mr_table *mrt;

	struct rtmsg *rtm;

	__be32 src, grp;

	u32 tableid;

	int err;



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

			  rtm_ipv4_policy, extack);

	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);

	if (err < 0)

		goto errout;



	rtm = nlmsg_data(nlh);



	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;

	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;

	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;