linux-kernel - [PATCH 3.13 049/172] gre: add link local route when local addr is any

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]

Date:	Tue,  4 Mar 2014 12:02:13 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org,
	"Steinar H. Gunderson" <sesse@...fundet.no>,
	Nicolas Dichtel <nicolas.dichtel@...nd.com>,
	"David S. Miller" <davem@...emloft.net>
Subject: [PATCH 3.13 049/172] gre: add link local route when local addr is any

3.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nicolas Dichtel <nicolas.dichtel@...nd.com>

[ Upstream commit 08b44656c08c8c2f73cdac2a058be2880e3361f2 ]

This bug was reported by Steinar H. Gunderson and was introduced by commit
f7cb8886335d ("sit/gre6: don't try to add the same route two times").

root@...gental:~# ip tunnel add foo mode gre remote 1.2.3.4 ttl 64
root@...gental:~# ip link set foo up mtu 1468
root@...gental:~# ip -6 route show dev foo
fe80::/64  proto kernel  metric 256

but after the above commit, no such route shows up.

There is no link local route because dev->dev_addr is 0 (because local ipv4
address is 0), hence no link local address is configured.

In this scenario, the link local address is added manually: 'ip -6 addr add
fe80::1 dev foo' and because prefix is /128, no link local route is added by the
kernel.

Even if the right things to do is to add the link local address with a /64
prefix, we need to restore the previous behavior to avoid breaking userpace.

Reported-by: Steinar H. Gunderson <sesse@...fundet.no>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@...nd.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/ipv6/addrconf.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2726,6 +2726,8 @@ static void addrconf_gre_config(struct n
 	ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
 	if (!ipv6_generate_eui64(addr.s6_addr + 8, dev))
 		addrconf_add_linklocal(idev, &addr);
+	else
+		addrconf_prefix_route(&addr, 64, dev, 0, 0);
 }
 #endif

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/