From: Eric W. Biederman Date: Mon, 14 Dec 2009 06:39:28 +0000 (-0800) Subject: net: Fix userspace RTM_NEWLINK notifications. X-Git-Tag: firefly_0821_release~11625^2~503 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ad496b34c6835a89dd3a8f6c07dfcf8a0dd7c277;p=firefly-linux-kernel-4.4.55.git net: Fix userspace RTM_NEWLINK notifications. commit d90a909e1f3e006a1d57fe11fd417173b6494701 upstream. I received some bug reports about userspace programs having problems because after RTM_NEWLINK was received they could not immeidate access files under /proc/sys/net/ because they had not been registered yet. The problem was trivailly fixed by moving the userspace notification from rtnetlink_event to the end of register_netdevice. Signed-off-by: Eric W. Biederman Cc: David Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/core/dev.c b/net/core/dev.c index fe10551d3671..584046eef9cb 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4860,6 +4860,11 @@ int register_netdevice(struct net_device *dev) rollback_registered(dev); dev->reg_state = NETREG_UNREGISTERED; } + /* + * Prevent userspace races by waiting until the network + * device is fully setup before sending notifications. + */ + rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); out: return ret; @@ -5398,6 +5403,12 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char /* Notify protocols, that a new device appeared. */ call_netdevice_notifiers(NETDEV_REGISTER, dev); + /* + * Prevent userspace races by waiting until the network + * device is fully setup before sending notifications. + */ + rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); + synchronize_net(); err = 0; out: diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index eb42873f2a3a..d4fd895e8712 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1334,13 +1334,11 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi case NETDEV_UNREGISTER: rtmsg_ifinfo(RTM_DELLINK, dev, ~0U); break; - case NETDEV_REGISTER: - rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); - break; case NETDEV_UP: case NETDEV_DOWN: rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING); break; + case NETDEV_REGISTER: case NETDEV_CHANGE: case NETDEV_GOING_DOWN: break;