From d77851bf68f48430a136af433783763ea7a35c3a Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 18 Jan 2019 10:46:25 -0800 Subject: 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: Jakub Kicinski Signed-off-by: David S. Miller --- net/mpls/af_mpls.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 59 insertions(+), 2 deletions(-) (limited to 'net/mpls/af_mpls.c') diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 7d55d4c04088..733c86db551b 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -2236,6 +2236,64 @@ errout: 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; -- cgit v1.2.3-58-ga151