diff options
Diffstat (limited to 'freed-ora/current/f24/wext-fix-message-delay-ordering.patch')
| -rw-r--r-- | freed-ora/current/f24/wext-fix-message-delay-ordering.patch | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/freed-ora/current/f24/wext-fix-message-delay-ordering.patch b/freed-ora/current/f24/wext-fix-message-delay-ordering.patch new file mode 100644 index 000000000..109b68da3 --- /dev/null +++ b/freed-ora/current/f24/wext-fix-message-delay-ordering.patch @@ -0,0 +1,122 @@ +From 8bf862739a7786ae72409220914df960a0aa80d8 Mon Sep 17 00:00:00 2001 +From: Johannes Berg <johannes.berg@intel.com> +Date: Wed, 27 Jan 2016 12:37:52 +0100 +Subject: wext: fix message delay/ordering + +Beniamino reported that he was getting an RTM_NEWLINK message for a +given interface, after the RTM_DELLINK for it. It turns out that the +message is a wireless extensions message, which was sent because the +interface had been connected and disconnection while it was deleted +caused a wext message. + +For its netlink messages, wext uses RTM_NEWLINK, but the message is +without all the regular rtnetlink attributes, so "ip monitor link" +prints just rudimentary information: + +5: wlan1: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default + link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff +Deleted 5: wlan1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default + link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff +5: wlan1: <BROADCAST,MULTICAST,UP> + link/ether +(from my hwsim reproduction) + +This can cause userspace to get confused since it doesn't expect an +RTM_NEWLINK message after RTM_DELLINK. + +The reason for this is that wext schedules a worker to send out the +messages, and the scheduling delay can cause the messages to get out +to userspace in different order. + +To fix this, have wext register a netdevice notifier and flush out +any pending messages when netdevice state changes. This fixes any +ordering whenever the original message wasn't sent by a notifier +itself. + +Cc: stable@vger.kernel.org +Reported-by: Beniamino Galvani <bgalvani@redhat.com> +Signed-off-by: Johannes Berg <johannes.berg@intel.com> +--- + net/wireless/wext-core.c | 51 +++++++++++++++++++++++++++++++++++++----------- + 1 file changed, 40 insertions(+), 11 deletions(-) + +diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c +index c8717c1..87dd619 100644 +--- a/net/wireless/wext-core.c ++++ b/net/wireless/wext-core.c +@@ -342,6 +342,39 @@ static const int compat_event_type_size[] = { + + /* IW event code */ + ++static void wireless_nlevent_flush(void) ++{ ++ struct sk_buff *skb; ++ struct net *net; ++ ++ ASSERT_RTNL(); ++ ++ for_each_net(net) { ++ while ((skb = skb_dequeue(&net->wext_nlevents))) ++ rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, ++ GFP_KERNEL); ++ } ++} ++ ++static int wext_netdev_notifier_call(struct notifier_block *nb, ++ unsigned long state, void *ptr) ++{ ++ /* ++ * When a netdev changes state in any way, flush all pending messages ++ * to avoid them going out in a strange order, e.g. RTM_NEWLINK after ++ * RTM_DELLINK, or with IFF_UP after without IFF_UP during dev_close() ++ * or similar - all of which could otherwise happen due to delays from ++ * schedule_work(). ++ */ ++ wireless_nlevent_flush(); ++ ++ return NOTIFY_OK; ++} ++ ++static struct notifier_block wext_netdev_notifier = { ++ .notifier_call = wext_netdev_notifier_call, ++}; ++ + static int __net_init wext_pernet_init(struct net *net) + { + skb_queue_head_init(&net->wext_nlevents); +@@ -360,7 +393,12 @@ static struct pernet_operations wext_pernet_ops = { + + static int __init wireless_nlevent_init(void) + { +- return register_pernet_subsys(&wext_pernet_ops); ++ int err = register_pernet_subsys(&wext_pernet_ops); ++ ++ if (err) ++ return err; ++ ++ return register_netdevice_notifier(&wext_netdev_notifier); + } + + subsys_initcall(wireless_nlevent_init); +@@ -368,17 +406,8 @@ subsys_initcall(wireless_nlevent_init); + /* Process events generated by the wireless layer or the driver. */ + static void wireless_nlevent_process(struct work_struct *work) + { +- struct sk_buff *skb; +- struct net *net; +- + rtnl_lock(); +- +- for_each_net(net) { +- while ((skb = skb_dequeue(&net->wext_nlevents))) +- rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, +- GFP_KERNEL); +- } +- ++ wireless_nlevent_flush(); + rtnl_unlock(); + } + +-- +cgit v0.12 + |
