From 18db594a1005d908d995a2fc8f5a7bf4286fdca0 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 6 Nov 2013 10:34:36 +0100 Subject: [PATCH] mac80211: fix scheduled scan rtnl deadlock When changing cfg80211 to use RTNL locking, this caused a deadlock in mac80211 as it calls cfg80211_sched_scan_stopped() from a work item that's on a workqueue that is flushed with the RTNL held. Fix this by simply using schedule_work(), the work only needs to finish running before the wiphy is unregistered, no other synchronisation (e.g. with suspend) is really required since for suspend userspace is already blocked anyway when we flush the workqueue so will only pick up the event after resume. Cc: stable@vger.kernel.org Fixes: 5fe231e87372 ("cfg80211: vastly simplify locking") Reported-and-tested-by: Eliad Peller Signed-off-by: Johannes Berg --- net/mac80211/main.c | 1 + net/mac80211/scan.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 21d5d44444d0..e765f77bb97a 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -1047,6 +1047,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) cancel_work_sync(&local->restart_work); cancel_work_sync(&local->reconfig_filter); + flush_work(&local->sched_scan_stopped_work); ieee80211_clear_tx_pending(local); rate_control_deinitialize(local); diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 5ad66a83ef7f..bcc4833d7542 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -1088,6 +1088,6 @@ void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) trace_api_sched_scan_stopped(local); - ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); + schedule_work(&local->sched_scan_stopped_work); } EXPORT_SYMBOL(ieee80211_sched_scan_stopped);