[PATCH 5.4 108/138] iwlwifi: mvm: dont call iwl_mvm_free_inactive_queue() under RCU

From: Greg Kroah-Hartman
Date: Mon Jul 27 2020 - 10:32:49 EST


From: Johannes Berg <johannes.berg@xxxxxxxxx>

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@xxxxxxxxxxxxxxx # v5.4+
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/iwlwifi.20200403112332.0f49448c133d.I17fd308bc4a9491859c9b112f4eb5d2c3fc18d7d@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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;
}