From patchwork Thu Dec 17 03:57:10 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [133/151] net: Fix userspace RTM_NEWLINK notifications. Date: Wed, 16 Dec 2009 17:57:10 -0000 From: gregkh@suse.de X-Patchwork-Id: 41302 Message-Id: <20091217035700.235380354@mini.kroah.org> To: linux-kernel@vger.kernel.org, stable@kernel.org, David Miller Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, netdev@vger.kernel.org, marcel@holtmann.org, "Eric W. Biederman" 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ 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 --- net/core/dev.c | 11 +++++++++++ net/core/rtnetlink.c | 4 +--- 2 files changed, 12 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4860,6 +4860,11 @@ int register_netdevice(struct net_device 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_ /* 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: --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1334,13 +1334,11 @@ static int rtnetlink_event(struct notifi 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;