Commit 7212462f authored Jun 01, 2017 by Nicolas Dichtel Committed by David S. Miller Jun 01, 2017

netlink: don't send unknown nsid

The NETLINK_F_LISTEN_ALL_NSID otion enables to listen all netns that have a
nsid assigned into the netns where the netlink socket is opened.
The nsid is sent as metadata to userland, but the existence of this nsid is
checked only for netns that are different from the socket netns. Thus, if
no nsid is assigned to the socket netns, NETNSA_NSID_NOT_ASSIGNED is
reported to the userland. This value is confusing and useless.
After this patch, only valid nsid are sent to userland.

Reported-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5ea6d691

net/netlink/af_netlink.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -62,6 +62,7 @@
		#include <asm/cacheflush.h>
		#include <linux/hash.h>
		#include <linux/genetlink.h>
		#include <linux/net_namespace.h>

		#include <net/net_namespace.h>
		#include <net/sock.h>
		@@ -1415,6 +1416,7 @@ static void do_one_broadcast(struct sock *sk,
		goto out;
		}
		NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net);
		if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED)
		NETLINK_CB(p->skb2).nsid_is_set = true;
		val = netlink_broadcast_deliver(sk, p->skb2);
		if (val < 0) {

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