linux-kernel - [PATCH 4.9 23/88] ipv6: Fix nlmsg_flags when splitting a multipath route

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200310123611.643941880@linuxfoundation.org>
Date:   Tue, 10 Mar 2020 13:38:31 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Benjamin Poirier <bpoirier@...ulusnetworks.com>,
        Michal Kubecek <mkubecek@...e.cz>,
        David Ahern <dsahern@...il.com>,
        "David S. Miller" <davem@...emloft.net>
Subject: [PATCH 4.9 23/88] ipv6: Fix nlmsg_flags when splitting a multipath route

From: Benjamin Poirier <bpoirier@...ulusnetworks.com>

[ Upstream commit afecdb376bd81d7e16578f0cfe82a1aec7ae18f3 ]

When splitting an RTA_MULTIPATH request into multiple routes and adding the
second and later components, we must not simply remove NLM_F_REPLACE but
instead replace it by NLM_F_CREATE. Otherwise, it may look like the netlink
message was malformed.

For example,
	ip route add 2001:db8::1/128 dev dummy0
	ip route change 2001:db8::1/128 nexthop via fe80::30:1 dev dummy0 \
		nexthop via fe80::30:2 dev dummy0
results in the following warnings:
[ 1035.057019] IPv6: RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE
[ 1035.057517] IPv6: NLM_F_CREATE should be set when creating new route

This patch makes the nlmsg sequence look equivalent for __ip6_ins_rt() to
what it would get if the multipath route had been added in multiple netlink
operations:
	ip route add 2001:db8::1/128 dev dummy0
	ip route change 2001:db8::1/128 nexthop via fe80::30:1 dev dummy0
	ip route append 2001:db8::1/128 nexthop via fe80::30:2 dev dummy0

Fixes: 27596472473a ("ipv6: fix ECMP route replacement")
Signed-off-by: Benjamin Poirier <bpoirier@...ulusnetworks.com>
Reviewed-by: Michal Kubecek <mkubecek@...e.cz>
Reviewed-by: David Ahern <dsahern@...il.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/ipv6/route.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3069,6 +3069,7 @@ static int ip6_route_multipath_add(struc
 		 */
 		cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
 						     NLM_F_REPLACE);
+		cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
 		nhn++;
 	}