net: ipv6: 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 <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 40b225f..8e11f9a 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -4822,6 +4822,73 @@ int rt6_dump_route(struct fib6_info *rt, void *p_arg)
                             arg->cb->nlh->nlmsg_seq, flags);
 }
 
+static int inet6_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_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_ipv6_policy, extack);
+
+       rtm = nlmsg_data(nlh);
+       if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
+           (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
+           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_ipv6_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_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
+               return -EINVAL;
+       }
+
+       for (i = 0; i <= RTA_MAX; i++) {
+               if (!tb[i])
+                       continue;
+
+               switch (i) {
+               case RTA_SRC:
+               case RTA_DST:
+               case RTA_IIF:
+               case RTA_OIF:
+               case RTA_MARK:
+               case RTA_UID:
+               case RTA_SPORT:
+               case RTA_DPORT:
+               case RTA_IP_PROTO:
+                       break;
+               default:
+                       NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
                              struct netlink_ext_ack *extack)
 {
@@ -4836,8 +4903,7 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
        struct flowi6 fl6 = {};
        bool fibmatch;
 
-       err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy,
-                         extack);
+       err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
        if (err < 0)
                goto errout;