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>

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index fbcbed6..00968c2 100644 (file)
--- 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);