cfg80211: fix regulatory restore upon user hints
Luis R. Rodriguez [Tue, 5 Apr 2011 17:49:03 +0000 (10:49 -0700)]
When we restore regulatory settings its possible CRDA
will not reply because of a bogus user entry. In this
case the bogus entry will prevent any further processing
on cfg80211 for regulatory domains even if we restore
regulatory settings.

To prevent this we suck out all pending requests when
restoring regulatory settings and add them back into the
queue after we have queued up the reset work.

The impact of not having this applied is that a user
with privileges can issue a userspace regulatory hint
while we are disasocciating and this would prevent any
further processing of regulatory domains.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/reg.c

index 3332d5b..7b1a89b 100644 (file)
@@ -1744,6 +1744,8 @@ static void restore_regulatory_settings(bool reset_user)
 {
        char alpha2[2];
        struct reg_beacon *reg_beacon, *btmp;
+       struct regulatory_request *reg_request, *tmp;
+       LIST_HEAD(tmp_reg_req_list);
 
        mutex_lock(&cfg80211_mutex);
        mutex_lock(&reg_mutex);
@@ -1751,6 +1753,25 @@ static void restore_regulatory_settings(bool reset_user)
        reset_regdomains();
        restore_alpha2(alpha2, reset_user);
 
+       /*
+        * If there's any pending requests we simply
+        * stash them to a temporary pending queue and
+        * add then after we've restored regulatory
+        * settings.
+        */
+       spin_lock(&reg_requests_lock);
+       if (!list_empty(&reg_requests_list)) {
+               list_for_each_entry_safe(reg_request, tmp,
+                                        &reg_requests_list, list) {
+                       if (reg_request->initiator !=
+                           NL80211_REGDOM_SET_BY_USER)
+                               continue;
+                       list_del(&reg_request->list);
+                       list_add_tail(&reg_request->list, &tmp_reg_req_list);
+               }
+       }
+       spin_unlock(&reg_requests_lock);
+
        /* Clear beacon hints */
        spin_lock_bh(&reg_pending_beacons_lock);
        if (!list_empty(&reg_pending_beacons)) {
@@ -1785,8 +1806,31 @@ static void restore_regulatory_settings(bool reset_user)
         */
        if (is_an_alpha2(alpha2))
                regulatory_hint_user(user_alpha2);
-}
 
+       if (list_empty(&tmp_reg_req_list))
+               return;
+
+       mutex_lock(&cfg80211_mutex);
+       mutex_lock(&reg_mutex);
+
+       spin_lock(&reg_requests_lock);
+       list_for_each_entry_safe(reg_request, tmp, &tmp_reg_req_list, list) {
+               REG_DBG_PRINT("Adding request for country %c%c back "
+                             "into the queue\n",
+                             reg_request->alpha2[0],
+                             reg_request->alpha2[1]);
+               list_del(&reg_request->list);
+               list_add_tail(&reg_request->list, &reg_requests_list);
+       }
+       spin_unlock(&reg_requests_lock);
+
+       mutex_unlock(&reg_mutex);
+       mutex_unlock(&cfg80211_mutex);
+
+       REG_DBG_PRINT("Kicking the queue\n");
+
+       schedule_work(&reg_work);
+}
 
 void regulatory_hint_disconnect(void)
 {