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 0E7E1C4167B for ; Mon, 15 Nov 2021 18:04:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E664D63253 for ; Mon, 15 Nov 2021 18:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239856AbhKOSEz (ORCPT ); Mon, 15 Nov 2021 13:04:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:50942 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236884AbhKORYp (ORCPT ); Mon, 15 Nov 2021 12:24:45 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CAB63613A3; Mon, 15 Nov 2021 17:17:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636996659; bh=IeOS9kzmGIdBs/D6fMAWn19e1Xh/xb3zoaiFTLJXHJU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nMhRTBPlwabgfZcYE5GRHAOZnVn9hwqxIhRPimpEz4ekj3wu+smytZY5/KuR/w2Fo Fnu5yib2R4qM7M+7gsX/OsIrfUV/dn6M4TMUelSzsHUHQhBxVTmkddzgaA8DKRP2y4 nWHEA5nHUPaOkY2RX0O6n4EdGxltFONk+wnbNWcI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Borkmann , Roopa Prabhu , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 221/355] net, neigh: Fix NTF_EXT_LEARNED in combination with NTF_USE Date: Mon, 15 Nov 2021 18:02:25 +0100 Message-Id: <20211115165320.907759698@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165313.549179499@linuxfoundation.org> References: <20211115165313.549179499@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Borkmann [ Upstream commit e4400bbf5b15750e1b59bf4722d18d99be60c69f ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 f94d405358a21..3a4cf53e38416 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -380,7 +380,7 @@ 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; @@ -413,6 +413,7 @@ do_alloc: 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); @@ -576,19 +577,18 @@ 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; @@ -675,7 +675,7 @@ out_neigh_release: 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); @@ -1945,7 +1945,9 @@ 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; -- 2.33.0