Commit 9b3757b0 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

rtnetlink: ifinfo: perform strict checks also for doit handler 



Make RTM_GETLINK'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 6300acb2

net/core/rtnetlink.c

+48 −1
Original line number Diff line number Diff line
@@ -3242,6 +3242,53 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, 
	return ret;

}



static int rtnl_valid_getlink_req(struct sk_buff *skb,

				  const struct nlmsghdr *nlh,

				  struct nlattr **tb,

				  struct netlink_ext_ack *extack)

{

	struct ifinfomsg *ifm;

	int i, err;



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

		NL_SET_ERR_MSG(extack, "Invalid header for get link");

		return -EINVAL;

	}



	if (!netlink_strict_get_check(skb))

		return nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,

				   extack);



	ifm = nlmsg_data(nlh);

	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||

	    ifm->ifi_change) {

		NL_SET_ERR_MSG(extack, "Invalid values in header for get link request");

		return -EINVAL;

	}



	err = nlmsg_parse_strict(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,

				 extack);

	if (err)

		return err;



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

		if (!tb[i])

			continue;



		switch (i) {

		case IFLA_IFNAME:

		case IFLA_EXT_MASK:

		case IFLA_TARGET_NETNSID:

			break;

		default:

			NL_SET_ERR_MSG(extack, "Unsupported attribute in get link request");

			return -EINVAL;

		}

	}



	return 0;

}



static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,

			struct netlink_ext_ack *extack)

{
@@ -3256,7 +3303,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, 
	int err;

	u32 ext_filter_mask = 0;



	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);

	err = rtnl_valid_getlink_req(skb, nlh, tb, extack);

	if (err < 0)

		return err;