releases/4.4.44/nl80211-fix-sched-scan-netlink-socket-owner-destruction.patch

   1 From 753aacfd2e95df6a0caf23c03dc309020765bea9 Mon Sep 17 00:00:00 2001
   2 From: Johannes Berg <johannes.berg@intel.com>
   3 Date: Thu, 5 Jan 2017 10:57:14 +0100
   4 Subject: nl80211: fix sched scan netlink socket owner destruction
   5
   6 From: Johannes Berg <johannes.berg@intel.com>
   7
   8 commit 753aacfd2e95df6a0caf23c03dc309020765bea9 upstream.
   9
  10 A single netlink socket might own multiple interfaces *and* a
  11 scheduled scan request (which might belong to another interface),
  12 so when it goes away both may need to be destroyed.
  13
  14 Remove the schedule_scan_stop indirection to fix this - it's only
  15 needed for interface destruction because of the way this works
  16 right now, with a single work taking care of all interfaces.
  17
  18 Fixes: 93a1e86ce10e4 ("nl80211: Stop scheduled scan if netlink client disappears")
  19 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21
  22 ---
  23  net/wireless/nl80211.c |   16 +++++++---------
  24  1 file changed, 7 insertions(+), 9 deletions(-)
  25
  26 --- a/net/wireless/nl80211.c
  27 +++ b/net/wireless/nl80211.c
  28 @@ -13168,13 +13168,17 @@ static int nl80211_netlink_notify(struct
  29
  30         list_for_each_entry_rcu(rdev, &cfg80211_rdev_list, list) {
  31                 bool schedule_destroy_work = false;
  32 -               bool schedule_scan_stop = false;
  33                 struct cfg80211_sched_scan_request *sched_scan_req =
  34                         rcu_dereference(rdev->sched_scan_req);
  35
  36                 if (sched_scan_req && notify->portid &&
  37 -                   sched_scan_req->owner_nlportid == notify->portid)
  38 -                       schedule_scan_stop = true;
  39 +                   sched_scan_req->owner_nlportid == notify->portid) {
  40 +                       sched_scan_req->owner_nlportid = 0;
  41 +
  42 +                       if (rdev->ops->sched_scan_stop &&
  43 +                           rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
  44 +                               schedule_work(&rdev->sched_scan_stop_wk);
  45 +               }
  46
  47                 list_for_each_entry_rcu(wdev, &rdev->wdev_list, list) {
  48                         cfg80211_mlme_unregister_socket(wdev, notify->portid);
  49 @@ -13205,12 +13209,6 @@ static int nl80211_netlink_notify(struct
  50                                 spin_unlock(&rdev->destroy_list_lock);
  51                                 schedule_work(&rdev->destroy_work);
  52                         }
  53 -               } else if (schedule_scan_stop) {
  54 -                       sched_scan_req->owner_nlportid = 0;
  55 -
  56 -                       if (rdev->ops->sched_scan_stop &&
  57 -                           rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
  58 -                               schedule_work(&rdev->sched_scan_stop_wk);
  59                 }
  60         }
  61