1. 18 Mar, 2016 1 commit
    • Johannes Berg's avatar
      wext: fix message delay/ordering · 746ba2ee
      Johannes Berg authored
      [ Upstream commit 8bf86273 ]
      
      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: default avatarBeniamino Galvani <bgalvani@redhat.com>
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      746ba2ee
  2. 17 Mar, 2016 1 commit
  3. 14 Mar, 2016 4 commits
  4. 09 Mar, 2016 34 commits