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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Johannes Berg <johannes.berg@intel.com>,
        Luca Coelho <luciano.coelho@intel.com>,
        Kalle Valo <kvalo@codeaurora.org>
Subject: [PATCH 5.7 144/179] iwlwifi: mvm: dont call iwl_mvm_free_inactive_queue() under RCU
Date:   Mon, 27 Jul 2020 16:05:19 +0200
Message-Id: <20200727134939.661424853@linuxfoundation.org>
In-Reply-To: <20200727134932.659499757@linuxfoundation.org>
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From: Johannes Berg <johannes.berg@intel.com>

commit fbb1461ad1d6eacca9beb69a2f3ce1b5398d399b upstream.

iwl_mvm_free_inactive_queue() will sleep in synchronize_net() under
some circumstances, so don't call it under RCU. There doesn't appear
to be a need for RCU protection around this particular call.

Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20200403112332.0f49448c133d.I17fd308bc4a9491859c9b112f4eb5d2c3fc18d7d@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/wireless/intel/iwlwifi/mvm/sta.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -1184,17 +1184,15 @@ static int iwl_mvm_inactivity_check(stru
 	for_each_set_bit(i, &changetid_queues, IWL_MAX_HW_QUEUES)
 		iwl_mvm_change_queue_tid(mvm, i);
 
+	rcu_read_unlock();
+
 	if (free_queue >= 0 && alloc_for_sta != IWL_MVM_INVALID_STA) {
 		ret = iwl_mvm_free_inactive_queue(mvm, free_queue, queue_owner,
 						  alloc_for_sta);
-		if (ret) {
-			rcu_read_unlock();
+		if (ret)
 			return ret;
-		}
 	}
 
-	rcu_read_unlock();
-
 	return free_queue;
 }