diff mbox series

[wireless,12/12] wifi: iwlwifi: mvm: Add locking to the rate read flow

Message ID 20230514120631.b52c9ed5c379.I15290b78e0d966c1b68278263776ca9de841d5fe@changeid
State New
Headers show
Series wifi: iwlwifi: fixes for v6.4 2023-05-14 | expand

Commit Message

Greenman, Gregory May 14, 2023, 9:15 a.m. UTC 
From: Ariel Malamud <ariel.malamud@intel.com>

The rs_drv_get_rate flow reads the lq_sta to return the optimal rate
for tx frames. This read flow is not protected thereby leaving
a small window, a few instructions wide, open to contention by an
asynchronous rate update. Indeed this race condition was hit and the
update occurred in the middle of the read.

Fix this by locking the lq_sta struct during read.

Signed-off-by: Ariel Malamud <ariel.malamud@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/rs.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
index a4c1e3bf4ff1..23266d0c9ce4 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
@@ -2691,6 +2691,8 @@  static void rs_drv_get_rate(void *mvm_r, struct ieee80211_sta *sta,
 		return;
 
 	lq_sta = mvm_sta;
+
+	spin_lock(&lq_sta->pers.lock);
 	iwl_mvm_hwrate_to_tx_rate_v1(lq_sta->last_rate_n_flags,
 				     info->band, &info->control.rates[0]);
 	info->control.rates[0].count = 1;
@@ -2705,6 +2707,7 @@  static void rs_drv_get_rate(void *mvm_r, struct ieee80211_sta *sta,
 		iwl_mvm_hwrate_to_tx_rate_v1(last_ucode_rate, info->band,
 					     &txrc->reported_rate);
 	}
+	spin_unlock(&lq_sta->pers.lock);
 }
 
 static void *rs_drv_alloc_sta(void *mvm_rate, struct ieee80211_sta *sta,