[PATCH 4.16 107/272] iwlwifi: mvm: take RCU lock before dereferencing

Greg Kroah-Hartman
2018-05-28T11:08:58Z

From: Sara Sharon <sara.sharon@intel.com>

[ Upstream commit f4f155e5ec04d381b2f0870817d93dbdc259aa63 ]

RCU isn't properly locked.

Fixes: 46d372af9935 ("iwlwifi: mvm: rs: new rate scale API - add FW notifications")
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/intel/iwlwifi/mvm/rs-fw.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/intel/iwlwifi/mvm/rs-fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs-fw.c
@@ -234,13 +234,15 @@ void iwl_mvm_tlc_update_notif(struct iwl
struct iwl_mvm_sta *mvmsta;
struct iwl_lq_sta_rs_fw *lq_sta;

+ rcu_read_lock();
+
notif = (void *)pkt->data;
mvmsta = iwl_mvm_sta_from_staid_rcu(mvm, notif->sta_id);

if (!mvmsta) {
IWL_ERR(mvm, "Invalid sta id (%d) in FW TLC notification\n",
notif->sta_id);
- return;
+ goto out;
}

lq_sta = &mvmsta->lq_sta.rs_fw;
@@ -251,6 +253,8 @@ void iwl_mvm_tlc_update_notif(struct iwl
IWL_DEBUG_RATE(mvm, "new rate_n_flags: 0x%X\n",
lq_sta->last_rate_n_flags);
}
+out:
+ rcu_read_unlock();
}

void rs_fw_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta *sta,