[PATCH 4.2.y-ckt 183/211] ipv6: keep existing flags when setting IFA_F_OPTIMISTIC

[Kamal Mostafa]

4.2.8-ckt1 -stable review patch.  If anyone has any objections, please let me know.

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

From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn at mork.no>

[ Upstream commit 9a1ec4612c9bfc94d4185e3459055a37a685e575 ]

Commit 64236f3f3d74 ("ipv6: introduce IFA_F_STABLE_PRIVACY flag")
failed to update the setting of the IFA_F_OPTIMISTIC flag, causing
the IFA_F_STABLE_PRIVACY flag to be lost if IFA_F_OPTIMISTIC is set.

Cc: Erik Kline <ek at google.com>
Cc: Fernando Gont <fgont at si6networks.com>
Cc: Lorenzo Colitti <lorenzo at google.com>
Cc: YOSHIFUJI Hideaki/吉藤英明 <hideaki.yoshifuji at miraclelinux.com>
Cc: Hannes Frederic Sowa <hannes at stressinduktion.org>
Fixes: 64236f3f3d74 ("ipv6: introduce IFA_F_STABLE_PRIVACY flag")
Signed-off-by: Bjørn Mork <bjorn at mork.no>
Acked-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/ipv6/addrconf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c8c1fea..6ab56d8 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2386,7 +2386,7 @@ ok:
 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 			if (in6_dev->cnf.optimistic_dad &&
 			    !net->ipv6.devconf_all->forwarding && sllao)
-				addr_flags = IFA_F_OPTIMISTIC;
+				addr_flags |= IFA_F_OPTIMISTIC;
 #endif
 
 			/* Do not allow to create too much of autoconfigured
-- 
1.9.1