[PATCH 3.16 170/305] mac80211_hwsim: Timer should be initialized before device registered

[Ben Hutchings]

3.16.63-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Vasyl Vavrychuk <vasyl.vavrychuk@xxxxxxxxxxxxxxx>

commit a1881c9b8a1edef0a5ae1d5c1b61406fe3402114 upstream.

Otherwise if network manager starts configuring Wi-Fi interface
immidiatelly after getting notification of its creation, we will get
NULL pointer dereference:

  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [<ffffffff95ae94c8>] hrtimer_active+0x28/0x50
  ...
  Call Trace:
   [<ffffffff95ae9997>] ? hrtimer_try_to_cancel+0x27/0x110
   [<ffffffff95ae9a95>] ? hrtimer_cancel+0x15/0x20
   [<ffffffffc0803bf0>] ? mac80211_hwsim_config+0x140/0x1c0 [mac80211_hwsim]

Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@xxxxxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/wireless/mac80211_hwsim.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -2153,6 +2153,10 @@ static int mac80211_hwsim_create_radio(i
 		schedule_timeout_interruptible(1);
 	}
 
+	tasklet_hrtimer_init(&data->beacon_timer,
+			     mac80211_hwsim_beacon,
+			     CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+
 	err = ieee80211_register_hw(hw);
 	if (err < 0) {
 		printk(KERN_DEBUG "mac80211_hwsim: ieee80211_register_hw failed (%d)\n",
@@ -2174,10 +2178,6 @@ static int mac80211_hwsim_create_radio(i
 				    data->debugfs,
 				    data, &hwsim_simulate_radar);
 
-	tasklet_hrtimer_init(&data->beacon_timer,
-			     mac80211_hwsim_beacon,
-			     CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
-
 	spin_lock_bh(&hwsim_radio_lock);
 	list_add_tail(&data->list, &hwsim_radios);
 	spin_unlock_bh(&hwsim_radio_lock);