From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 17 Nov 2008 07:20:31 +0000 (-0800)
Subject: rtnetlink: propagate error from dev_change_flags in do_setlink()
X-Git-Tag: firefly_0821_release~16788^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5f9021cfdc3524a4c5e3d7ae2d049eb7adcd6776;p=firefly-linux-kernel-4.4.55.git

rtnetlink: propagate error from dev_change_flags in do_setlink()

Unlike ifconfig, iproute doesn't report an error when setting
an interface up fails:

(example: put wireless network mac80211 interface into repeater mode
with iwconfig but do not set a peer MAC address, it should fail with
-ENOLINK)

without patch:
# ip link set wlan0 up ; echo $?
0
#

with patch:
# ip link set wlan0 up ; echo $?
RTNETLINK answers: Link has been severed
2
#

Propagate the return value from dev_change_flags() to fix this.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Tested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 31f29d2989fd..4dfb6b4d4559 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -878,7 +878,9 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 		if (ifm->ifi_change)
 			flags = (flags & ifm->ifi_change) |
 				(dev->flags & ~ifm->ifi_change);
-		dev_change_flags(dev, flags);
+		err = dev_change_flags(dev, flags);
+		if (err < 0)
+			goto errout;
 	}
 
 	if (tb[IFLA_TXQLEN])