6 files changed, 92 insertions, 47 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 922002105062..11743d48cbc2 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -212,6 +212,39 @@ static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
         rdev_rfkill_poll(rdev);
 }
 
+void cfg80211_stop_p2p_device(struct cfg80211_registered_device *rdev,
+                              struct wireless_dev *wdev)
+{
+        lockdep_assert_held(&rdev->devlist_mtx);
+        lockdep_assert_held(&rdev->sched_scan_mtx);
+
+        if (WARN_ON(wdev->iftype != NL80211_IFTYPE_P2P_DEVICE))
+                return;
+
+        if (!wdev->p2p_started)
+                return;
+
+        rdev_stop_p2p_device(rdev, wdev);
+        wdev->p2p_started = false;
+
+        rdev->opencount--;
+
+        if (rdev->scan_req && rdev->scan_req->wdev == wdev) {
+                bool busy = work_busy(&rdev->scan_done_wk);
+
+                /*
+                 * If the work isn't pending or running (in which case it would
+                 * be waiting for the lock we hold) the driver didn't properly
+                 * cancel the scan when the interface was removed. In this case
+                 * warn and leak the scan request object to not crash later.
+                 */
+                WARN_ON(!busy);
+
+                rdev->scan_req->aborted = true;
+                ___cfg80211_scan_done(rdev, !busy);
+        }
+}
+
 static int cfg80211_rfkill_set_block(void *data, bool blocked)
 {
         struct cfg80211_registered_device *rdev = data;
@@ -221,7 +254,8 @@ static int cfg80211_rfkill_set_block(void *data, bool blocked)
                 return 0;
 
         rtnl_lock();
-        mutex_lock(&rdev->devlist_mtx);
+
+        /* read-only iteration need not hold the devlist_mtx */
 
         list_for_each_entry(wdev, &rdev->wdev_list, list) {
                 if (wdev->netdev) {
@@ -231,18 +265,18 @@ static int cfg80211_rfkill_set_block(void *data, bool blocked)
                 /* otherwise, check iftype */
                 switch (wdev->iftype) {
                 case NL80211_IFTYPE_P2P_DEVICE:
-                        if (!wdev->p2p_started)
-                                break;
-                        rdev_stop_p2p_device(rdev, wdev);
-                        wdev->p2p_started = false;
-                        rdev->opencount--;
+                        /* but this requires it */
+                        mutex_lock(&rdev->devlist_mtx);
+                        mutex_lock(&rdev->sched_scan_mtx);
+                        cfg80211_stop_p2p_device(rdev, wdev);
+                        mutex_unlock(&rdev->sched_scan_mtx);
+                        mutex_unlock(&rdev->devlist_mtx);
                         break;
                 default:
                         break;
                 }
         }
 
-        mutex_unlock(&rdev->devlist_mtx);
         rtnl_unlock();
 
         return 0;
@@ -745,17 +779,13 @@ static void wdev_cleanup_work(struct work_struct *work)
         wdev = container_of(work, struct wireless_dev, cleanup_work);
         rdev = wiphy_to_dev(wdev->wiphy);
 
-        cfg80211_lock_rdev(rdev);
+        mutex_lock(&rdev->sched_scan_mtx);
 
         if (WARN_ON(rdev->scan_req && rdev->scan_req->wdev == wdev)) {
                 rdev->scan_req->aborted = true;
                 ___cfg80211_scan_done(rdev, true);
         }
 
-        cfg80211_unlock_rdev(rdev);
-
-        mutex_lock(&rdev->sched_scan_mtx);
-
         if (WARN_ON(rdev->sched_scan_req &&
                     rdev->sched_scan_req->dev == wdev->netdev)) {
                 __cfg80211_stop_sched_scan(rdev, false);
@@ -781,21 +811,19 @@ void cfg80211_unregister_wdev(struct wireless_dev *wdev)
                 return;
 
         mutex_lock(&rdev->devlist_mtx);
+        mutex_lock(&rdev->sched_scan_mtx);
         list_del_rcu(&wdev->list);
         rdev->devlist_generation++;
 
         switch (wdev->iftype) {
         case NL80211_IFTYPE_P2P_DEVICE:
-                if (!wdev->p2p_started)
-                        break;
-                rdev_stop_p2p_device(rdev, wdev);
-                wdev->p2p_started = false;
-                rdev->opencount--;
+                cfg80211_stop_p2p_device(rdev, wdev);
                 break;
         default:
                 WARN_ON_ONCE(1);
                 break;
         }
+        mutex_unlock(&rdev->sched_scan_mtx);
         mutex_unlock(&rdev->devlist_mtx);
 }
 EXPORT_SYMBOL(cfg80211_unregister_wdev);
@@ -937,6 +965,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
                 cfg80211_update_iface_num(rdev, wdev->iftype, 1);
                 cfg80211_lock_rdev(rdev);
                 mutex_lock(&rdev->devlist_mtx);
+                mutex_lock(&rdev->sched_scan_mtx);
                 wdev_lock(wdev);
                 switch (wdev->iftype) {
 #ifdef CONFIG_CFG80211_WEXT
@@ -968,6 +997,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
                         break;
                 }
                 wdev_unlock(wdev);
+                mutex_unlock(&rdev->sched_scan_mtx);
                 rdev->opencount++;
                 mutex_unlock(&rdev->devlist_mtx);
                 cfg80211_unlock_rdev(rdev);
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 3aec0e429d8a..5845c2b37aa8 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -503,6 +503,9 @@ int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
                                enum nl80211_iftype iftype, int num);
 
+void cfg80211_stop_p2p_device(struct cfg80211_registered_device *rdev,
+                              struct wireless_dev *wdev);
+
 #define CFG80211_MAX_NUM_DIFFERENT_CHANNELS 10
 
 #ifdef CONFIG_CFG80211_DEVELOPER_WARNINGS
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d44ab216c0ec..58e13a8c95f9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4702,14 +4702,19 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
         if (!rdev->ops->scan)
                 return -EOPNOTSUPP;
 
-        if (rdev->scan_req)
-                return -EBUSY;
+        mutex_lock(&rdev->sched_scan_mtx);
+        if (rdev->scan_req) {
+                err = -EBUSY;
+                goto unlock;
+        }
 
         if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
                 n_channels = validate_scan_freqs(
                                 info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]);
-                if (!n_channels)
-                        return -EINVAL;
+                if (!n_channels) {
+                        err = -EINVAL;
+                        goto unlock;
+                }
         } else {
                 enum ieee80211_band band;
                 n_channels = 0;
@@ -4723,23 +4728,29 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
                 nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_SSIDS], tmp)
                         n_ssids++;
 
-        if (n_ssids > wiphy->max_scan_ssids)
-                return -EINVAL;
+        if (n_ssids > wiphy->max_scan_ssids) {
+                err = -EINVAL;
+                goto unlock;
+        }
 
         if (info->attrs[NL80211_ATTR_IE])
                 ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
         else
                 ie_len = 0;
 
-        if (ie_len > wiphy->max_scan_ie_len)
-                return -EINVAL;
+        if (ie_len > wiphy->max_scan_ie_len) {
+                err = -EINVAL;
+                goto unlock;
+        }
 
         request = kzalloc(sizeof(*request)
                         + sizeof(*request->ssids) * n_ssids
                         + sizeof(*request->channels) * n_channels
                         + ie_len, GFP_KERNEL);
-        if (!request)
-                return -ENOMEM;
+        if (!request) {
+                err = -ENOMEM;
+                goto unlock;
+        }
 
         if (n_ssids)
                 request->ssids = (void *)&request->channels[n_channels];
@@ -4876,6 +4887,8 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
                 kfree(request);
         }
 
+ unlock:
+        mutex_unlock(&rdev->sched_scan_mtx);
         return err;
 }
 
@@ -7749,20 +7762,9 @@ static int nl80211_stop_p2p_device(struct sk_buff *skb, struct genl_info *info)
         if (!rdev->ops->stop_p2p_device)
                 return -EOPNOTSUPP;
 
-        if (!wdev->p2p_started)
-                return 0;
-
-        rdev_stop_p2p_device(rdev, wdev);
-        wdev->p2p_started = false;
-
-        mutex_lock(&rdev->devlist_mtx);
-        rdev->opencount--;
-        mutex_unlock(&rdev->devlist_mtx);
-
-        if (WARN_ON(rdev->scan_req && rdev->scan_req->wdev == wdev)) {
-                rdev->scan_req->aborted = true;
-                ___cfg80211_scan_done(rdev, true);
-        }
+        mutex_lock(&rdev->sched_scan_mtx);
+        cfg80211_stop_p2p_device(rdev, wdev);
+        mutex_unlock(&rdev->sched_scan_mtx);
 
         return 0;
 }
@@ -8486,7 +8488,7 @@ static int nl80211_add_scan_req(struct sk_buff *msg,
         struct nlattr *nest;
         int i;
 
-        ASSERT_RDEV_LOCK(rdev);
+        lockdep_assert_held(&rdev->sched_scan_mtx);
 
         if (WARN_ON(!req))
                 return 0;
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index e93bd31d23bb..fd99ea495b7e 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -169,7 +169,7 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
         union iwreq_data wrqu;
 #endif
 
-        ASSERT_RDEV_LOCK(rdev);
+        lockdep_assert_held(&rdev->sched_scan_mtx);
 
         request = rdev->scan_req;
 
@@ -230,9 +230,9 @@ void __cfg80211_scan_done(struct work_struct *wk)
         rdev = container_of(wk, struct cfg80211_registered_device,
                             scan_done_wk);
 
-        cfg80211_lock_rdev(rdev);
+        mutex_lock(&rdev->sched_scan_mtx);
         ___cfg80211_scan_done(rdev, false);
-        cfg80211_unlock_rdev(rdev);
+        mutex_unlock(&rdev->sched_scan_mtx);
 }
 
 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
@@ -1062,6 +1062,7 @@ int cfg80211_wext_siwscan(struct net_device *dev,
         if (IS_ERR(rdev))
                 return PTR_ERR(rdev);
 
+        mutex_lock(&rdev->sched_scan_mtx);
         if (rdev->scan_req) {
                 err = -EBUSY;
                 goto out;
@@ -1168,6 +1169,7 @@ int cfg80211_wext_siwscan(struct net_device *dev,
                 dev_hold(dev);
         }
  out:
+        mutex_unlock(&rdev->sched_scan_mtx);
         kfree(creq);
         cfg80211_unlock_rdev(rdev);
         return err;
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index f432bd3755b1..09d994d192ff 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -85,6 +85,7 @@ static int cfg80211_conn_scan(struct wireless_dev *wdev)
         ASSERT_RTNL();
         ASSERT_RDEV_LOCK(rdev);
         ASSERT_WDEV_LOCK(wdev);
+        lockdep_assert_held(&rdev->sched_scan_mtx);
 
         if (rdev->scan_req)
                 return -EBUSY;
@@ -320,11 +321,9 @@ void cfg80211_sme_scan_done(struct net_device *dev)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
 
-        mutex_lock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
         wdev_lock(wdev);
         __cfg80211_sme_scan_done(dev);
         wdev_unlock(wdev);
-        mutex_unlock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
 }
 
 void cfg80211_sme_rx_auth(struct net_device *dev,
@@ -924,9 +923,12 @@ int cfg80211_connect(struct cfg80211_registered_device *rdev,
         int err;
 
         mutex_lock(&rdev->devlist_mtx);
+        /* might request scan - scan_mtx -> wdev_mtx dependency */
+        mutex_lock(&rdev->sched_scan_mtx);
         wdev_lock(dev->ieee80211_ptr);
         err = __cfg80211_connect(rdev, dev, connect, connkeys, NULL);
         wdev_unlock(dev->ieee80211_ptr);
+        mutex_unlock(&rdev->sched_scan_mtx);
         mutex_unlock(&rdev->devlist_mtx);
 
         return err;
diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c
index fb9622f6d99c..e79cb5c0655a 100644
--- a/net/wireless/wext-sme.c
+++ b/net/wireless/wext-sme.c
@@ -89,6 +89,7 @@ int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
 
         cfg80211_lock_rdev(rdev);
         mutex_lock(&rdev->devlist_mtx);
+        mutex_lock(&rdev->sched_scan_mtx);
         wdev_lock(wdev);
 
         if (wdev->sme_state != CFG80211_SME_IDLE) {
@@ -135,6 +136,7 @@ int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
         err = cfg80211_mgd_wext_connect(rdev, wdev);
  out:
         wdev_unlock(wdev);
+        mutex_unlock(&rdev->sched_scan_mtx);
         mutex_unlock(&rdev->devlist_mtx);
         cfg80211_unlock_rdev(rdev);
         return err;
@@ -190,6 +192,7 @@ int cfg80211_mgd_wext_siwessid(struct net_device *dev,
 
         cfg80211_lock_rdev(rdev);
         mutex_lock(&rdev->devlist_mtx);
+        mutex_lock(&rdev->sched_scan_mtx);
         wdev_lock(wdev);
 
         err = 0;
@@ -223,6 +226,7 @@ int cfg80211_mgd_wext_siwessid(struct net_device *dev,
         err = cfg80211_mgd_wext_connect(rdev, wdev);
  out:
         wdev_unlock(wdev);
+        mutex_unlock(&rdev->sched_scan_mtx);
         mutex_unlock(&rdev->devlist_mtx);
         cfg80211_unlock_rdev(rdev);
         return err;
@@ -285,6 +289,7 @@ int cfg80211_mgd_wext_siwap(struct net_device *dev,
 
         cfg80211_lock_rdev(rdev);
         mutex_lock(&rdev->devlist_mtx);
+        mutex_lock(&rdev->sched_scan_mtx);
         wdev_lock(wdev);
 
         if (wdev->sme_state != CFG80211_SME_IDLE) {
@@ -313,6 +318,7 @@ int cfg80211_mgd_wext_siwap(struct net_device *dev,
         err = cfg80211_mgd_wext_connect(rdev, wdev);
  out:
         wdev_unlock(wdev);
+        mutex_unlock(&rdev->sched_scan_mtx);
         mutex_unlock(&rdev->devlist_mtx);
         cfg80211_unlock_rdev(rdev);
         return err;