From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B3F1C43217 for ; Mon, 11 Oct 2021 12:12:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2363460F92 for ; Mon, 11 Oct 2021 12:12:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234910AbhJKMOt (ORCPT ); Mon, 11 Oct 2021 08:14:49 -0400 Received: from www62.your-server.de ([213.133.104.62]:36932 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234675AbhJKMOr (ORCPT ); Mon, 11 Oct 2021 08:14:47 -0400 Received: from 226.206.1.85.dynamic.wline.res.cust.swisscom.ch ([85.1.206.226] helo=localhost) by www62.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1mZuAg-000Edr-59; Mon, 11 Oct 2021 14:12:46 +0200 From: Daniel Borkmann To: davem@davemloft.net, kuba@kernel.org Cc: roopa@nvidia.com, dsahern@kernel.org, m@lambda.lt, john.fastabend@gmail.com, netdev@vger.kernel.org, bpf@vger.kernel.org, Daniel Borkmann Subject: [PATCH net-next 1/4] net, neigh: Fix NTF_EXT_LEARNED in combination with NTF_USE Date: Mon, 11 Oct 2021 14:12:35 +0200 Message-Id: <20211011121238.25542-2-daniel@iogearbox.net> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20211011121238.25542-1-daniel@iogearbox.net> References: <20211011121238.25542-1-daniel@iogearbox.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.103.3/26319/Mon Oct 11 10:18:47 2021) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The NTF_EXT_LEARNED neigh flag is usually propagated back to user space upon dump of the neighbor table. However, when used in combination with NTF_USE flag this is not the case despite exempting the entry from the garbage collector. This results in inconsistent state since entries are typically marked in neigh->flags with NTF_EXT_LEARNED, but here they are not. Fix it by propagating the creation flag to ___neigh_create(). Before fix: # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE [...] After fix: # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE [...] Fixes: 9ce33e46531d ("neighbour: support for NTF_EXT_LEARNED flag") Signed-off-by: Daniel Borkmann Acked-by: Roopa Prabhu --- net/core/neighbour.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 2d5bc3a75fae..8457d5f97022 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -379,7 +379,7 @@ EXPORT_SYMBOL(neigh_ifdown); static struct neighbour *neigh_alloc(struct neigh_table *tbl, struct net_device *dev, - bool exempt_from_gc) + u8 flags, bool exempt_from_gc) { struct neighbour *n = NULL; unsigned long now = jiffies; @@ -412,6 +412,7 @@ static struct neighbour *neigh_alloc(struct neigh_table *tbl, n->updated = n->used = now; n->nud_state = NUD_NONE; n->output = neigh_blackhole; + n->flags = flags; seqlock_init(&n->hh.hh_lock); n->parms = neigh_parms_clone(&tbl->parms); timer_setup(&n->timer, neigh_timer_handler, 0); @@ -575,19 +576,18 @@ struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, } EXPORT_SYMBOL(neigh_lookup_nodev); -static struct neighbour *___neigh_create(struct neigh_table *tbl, - const void *pkey, - struct net_device *dev, - bool exempt_from_gc, bool want_ref) +static struct neighbour * +___neigh_create(struct neigh_table *tbl, const void *pkey, + struct net_device *dev, u8 flags, + bool exempt_from_gc, bool want_ref) { - struct neighbour *n1, *rc, *n = neigh_alloc(tbl, dev, exempt_from_gc); - u32 hash_val; - unsigned int key_len = tbl->key_len; - int error; + u32 hash_val, key_len = tbl->key_len; + struct neighbour *n1, *rc, *n; struct neigh_hash_table *nht; + int error; + n = neigh_alloc(tbl, dev, flags, exempt_from_gc); trace_neigh_create(tbl, dev, pkey, n, exempt_from_gc); - if (!n) { rc = ERR_PTR(-ENOBUFS); goto out; @@ -674,7 +674,7 @@ static struct neighbour *___neigh_create(struct neigh_table *tbl, struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, struct net_device *dev, bool want_ref) { - return ___neigh_create(tbl, pkey, dev, false, want_ref); + return ___neigh_create(tbl, pkey, dev, 0, false, want_ref); } EXPORT_SYMBOL(__neigh_create); @@ -1942,7 +1942,9 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, exempt_from_gc = ndm->ndm_state & NUD_PERMANENT || ndm->ndm_flags & NTF_EXT_LEARNED; - neigh = ___neigh_create(tbl, dst, dev, exempt_from_gc, true); + neigh = ___neigh_create(tbl, dst, dev, + ndm->ndm_flags & NTF_EXT_LEARNED, + exempt_from_gc, true); if (IS_ERR(neigh)) { err = PTR_ERR(neigh); goto out; -- 2.27.0