mac80211: fix modprobe deadlock by not calling wep_init under rtnl_lock

- ieee80211_wep_init(), which is called with rtnl_lock held, blocks in
   request_module() [waiting for modprobe to load a crypto module].

 - modprobe blocks in a call to flush_workqueue(), when it closes a TTY
   [presumably when it exits].

 - The workqueue item linkwatch_event() blocks on rtnl_lock.

There's no reason for wep_init() to be called with rtnl_lock held, so
just move it outside the critical section.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 9 insertions, 10 deletions

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index fbcbed6cad01..00968c2d22bb 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -909,6 +909,13 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
         if (result < 0)
                 goto fail_sta_info;
 
+        result = ieee80211_wep_init(local);
+        if (result < 0) {
+                printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
+                       wiphy_name(local->hw.wiphy), result);
+                goto fail_wep;
+        }
+
         rtnl_lock();
         result = dev_alloc_name(local->mdev, local->mdev->name);
         if (result < 0)
@@ -930,14 +937,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
                 goto fail_rate;
         }
 
-        result = ieee80211_wep_init(local);
-
-        if (result < 0) {
-                printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
-                       wiphy_name(local->hw.wiphy), result);
-                goto fail_wep;
-        }
-
         /* add one default STA interface if supported */
         if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION)) {
                 result = ieee80211_if_add(local, "wlan%d", NULL,
@@ -967,13 +966,13 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 
         return 0;
 
-fail_wep:
-        rate_control_deinitialize(local);
 fail_rate:
         unregister_netdevice(local->mdev);
         local->mdev = NULL;
 fail_dev:
         rtnl_unlock();
+        ieee80211_wep_free(local);
+fail_wep:
         sta_info_stop(local);
 fail_sta_info:
         debugfs_hw_del(local);