Merge branch 'net-use-strict-checks-in-doit-handlers'

Jakub Kicinski says:

====================
net: use strict checks in doit handlers

This series extends strict argument checking to doit handlers
of the GET* nature.  This is a bit tricky since strict checking
flag has already been released..

iproute2 did not have a release with strick checks enabled,
and it will only need a minor one-liner to pass strick checks
after all the work that DaveA has already done.

Big thanks to Dave Ahern for help and guidence.

v2:
 - remove unnecessary check in patch 5 (Nicolas);
 - add path 7 (DaveA);
 - improve messages in patch 8 (DaveA).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 36 insertions, 2 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index b02fb19df2cc..17f36317363d 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -778,6 +778,41 @@ nla_put_failure:
 	return -EMSGSIZE;
 }
 
+static int rtnl_net_valid_getid_req(struct sk_buff *skb,
+				    const struct nlmsghdr *nlh,
+				    struct nlattr **tb,
+				    struct netlink_ext_ack *extack)
+{
+	int i, err;
+
+	if (!netlink_strict_get_check(skb))
+		return nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
+				   rtnl_net_policy, extack);
+
+	err = nlmsg_parse_strict(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
+				 rtnl_net_policy, extack);
+	if (err)
+		return err;
+
+	for (i = 0; i <= NETNSA_MAX; i++) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case NETNSA_PID:
+		case NETNSA_FD:
+		case NETNSA_NSID:
+		case NETNSA_TARGET_NSID:
+			break;
+		default:
+			NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
 			  struct netlink_ext_ack *extack)
 {
@@ -793,8 +828,7 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
 	struct sk_buff *msg;
 	int err;
 
-	err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
-			  rtnl_net_policy, extack);
+	err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
 	if (err < 0)
 		return err;
 	if (tb[NETNSA_PID]) {