From: Xin Long <lucien.xin@gmail.com>
Subject: rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlink
Patch-mainline: v4.14-rc6
Git-commit: 64ff90cc2e6f42596d7a0c37e41dc95292bb63b1
References: git-fixes

The check 'status & DO_SETLINK_NOTIFY' in do_setlink doesn't really
work after status & DO_SETLINK_MODIFIED, as:

  DO_SETLINK_MODIFIED 0x1
  DO_SETLINK_NOTIFY 0x3

Considering that notifications are suppposed to be sent only when
status have the flag DO_SETLINK_NOTIFY, the right check would be:

  (status & DO_SETLINK_NOTIFY) == DO_SETLINK_NOTIFY

This would avoid lots of duplicated notifications when setting some
properties of a link.

Fixes: ba9989069f4e ("rtnl/do_setlink(): notify when a netdev is modified")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Denis Kirjanov <dkirjanov@suse.com>
---
 net/core/rtnetlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index ab98c1c8b6f3..3e98fb557598 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2248,7 +2248,7 @@ static int do_setlink(const struct sk_buff *skb,
 
 errout:
 	if (status & DO_SETLINK_MODIFIED) {
-		if (status & DO_SETLINK_NOTIFY)
+		if ((status & DO_SETLINK_NOTIFY) == DO_SETLINK_NOTIFY)
 			netdev_state_change(dev);
 
 		if (err < 0)
-- 
2.12.3