3 files changed, 23 insertions, 9 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index fb306814576a..a6893602f87a 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2582,7 +2582,7 @@ static int ieee80211_cancel_roc(struct ieee80211_local *local,
                         list_del(&dep->list);
                         mutex_unlock(&local->mtx);
 
-                        ieee80211_roc_notify_destroy(dep);
+                        ieee80211_roc_notify_destroy(dep, true);
                         return 0;
                 }
 
@@ -2622,7 +2622,7 @@ static int ieee80211_cancel_roc(struct ieee80211_local *local,
                         ieee80211_start_next_roc(local);
                 mutex_unlock(&local->mtx);
 
-                ieee80211_roc_notify_destroy(found);
+                ieee80211_roc_notify_destroy(found, true);
         } else {
                 /* work may be pending so use it all the time */
                 found->abort = true;
@@ -2632,6 +2632,8 @@ static int ieee80211_cancel_roc(struct ieee80211_local *local,
 
                 /* work will clean up etc */
                 flush_delayed_work(&found->work);
+                WARN_ON(!found->to_be_freed);
+                kfree(found);
         }
 
         return 0;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 388580a1bada..7bdefd901f9d 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -309,6 +309,7 @@ struct ieee80211_roc_work {
         struct ieee80211_channel *chan;
 
         bool started, abort, hw_begun, notified;
+        bool to_be_freed;
 
         unsigned long hw_start_time;
 
@@ -1347,7 +1348,7 @@ void ieee80211_offchannel_return(struct ieee80211_local *local);
 void ieee80211_roc_setup(struct ieee80211_local *local);
 void ieee80211_start_next_roc(struct ieee80211_local *local);
 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata);
-void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc);
+void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free);
 void ieee80211_sw_roc_work(struct work_struct *work);
 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc);
 
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index cc79b4a2e821..430bd254e496 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -297,10 +297,13 @@ void ieee80211_start_next_roc(struct ieee80211_local *local)
         }
 }
 
-void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
+void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free)
 {
         struct ieee80211_roc_work *dep, *tmp;
 
+        if (WARN_ON(roc->to_be_freed))
+                return;
+
         /* was never transmitted */
         if (roc->frame) {
                 cfg80211_mgmt_tx_status(&roc->sdata->wdev,
@@ -316,9 +319,12 @@ void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
                                                    GFP_KERNEL);
 
         list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
-                ieee80211_roc_notify_destroy(dep);
+                ieee80211_roc_notify_destroy(dep, true);
 
-        kfree(roc);
+        if (free)
+                kfree(roc);
+        else
+                roc->to_be_freed = true;
 }
 
 void ieee80211_sw_roc_work(struct work_struct *work)
@@ -331,6 +337,9 @@ void ieee80211_sw_roc_work(struct work_struct *work)
 
         mutex_lock(&local->mtx);
 
+        if (roc->to_be_freed)
+                goto out_unlock;
+
         if (roc->abort)
                 goto finish;
 
@@ -370,7 +379,7 @@ void ieee80211_sw_roc_work(struct work_struct *work)
  finish:
                 list_del(&roc->list);
                 started = roc->started;
-                ieee80211_roc_notify_destroy(roc);
+                ieee80211_roc_notify_destroy(roc, !roc->abort);
 
                 if (started) {
                         drv_flush(local, false);
@@ -410,7 +419,7 @@ static void ieee80211_hw_roc_done(struct work_struct *work)
 
         list_del(&roc->list);
 
-        ieee80211_roc_notify_destroy(roc);
+        ieee80211_roc_notify_destroy(roc, true);
 
         /* if there's another roc, start it now */
         ieee80211_start_next_roc(local);
@@ -460,12 +469,14 @@ void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
         list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
                 if (local->ops->remain_on_channel) {
                         list_del(&roc->list);
-                        ieee80211_roc_notify_destroy(roc);
+                        ieee80211_roc_notify_destroy(roc, true);
                 } else {
                         ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
 
                         /* work will clean up etc */
                         flush_delayed_work(&roc->work);
+                        WARN_ON(!roc->to_be_freed);
+                        kfree(roc);
                 }
         }