net: ipv6: netconf: perform strict checks also for doit handlers

Make RTM_GETNETCONF'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/addrconf.c b/net/ipv6/addrconf.c
index 339a82cfe5f2482c168438a1ce56c92929a5bd6a..57198b3c86da75922d5a9b062f26b34b84bba342 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -597,6 +597,43 @@ static const struct nla_policy devconf_ipv6_policy[NETCONFA_MAX+1] = {
        [NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN]  = { .len = sizeof(int) },
 };
 
+static int inet6_netconf_valid_get_req(struct sk_buff *skb,
+                                      const struct nlmsghdr *nlh,
+                                      struct nlattr **tb,
+                                      struct netlink_ext_ack *extack)
+{
+       int i, err;
+
+       if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
+               NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf get request");
+               return -EINVAL;
+       }
+
+       if (!netlink_strict_get_check(skb))
+               return nlmsg_parse(nlh, sizeof(struct netconfmsg), tb,
+                                  NETCONFA_MAX, devconf_ipv6_policy, extack);
+
+       err = nlmsg_parse_strict(nlh, sizeof(struct netconfmsg), tb,
+                                NETCONFA_MAX, devconf_ipv6_policy, extack);
+       if (err)
+               return err;
+
+       for (i = 0; i <= NETCONFA_MAX; i++) {
+               if (!tb[i])
+                       continue;
+
+               switch (i) {
+               case NETCONFA_IFINDEX:
+                       break;
+               default:
+                       NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
 static int inet6_netconf_get_devconf(struct sk_buff *in_skb,
                                     struct nlmsghdr *nlh,
                                     struct netlink_ext_ack *extack)
@@ -605,14 +642,12 @@ static int inet6_netconf_get_devconf(struct sk_buff *in_skb,
        struct nlattr *tb[NETCONFA_MAX+1];
        struct inet6_dev *in6_dev = NULL;
        struct net_device *dev = NULL;
-       struct netconfmsg *ncm;
        struct sk_buff *skb;
        struct ipv6_devconf *devconf;
        int ifindex;
        int err;
 
-       err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX,
-                         devconf_ipv6_policy, extack);
+       err = inet6_netconf_valid_get_req(in_skb, nlh, tb, extack);
        if (err < 0)
                return err;