From 7402fb48efff67be21392e81df8a6c51bc491c6f Mon Sep 17 00:00:00 2001 From: Ariel Malamud Date: Sun, 14 May 2023 12:15:55 +0300 Subject: [PATCH] wifi: iwlwifi: mvm: Add locking to the rate read flow [ Upstream commit a8938bc881d2a03f9b77f19fae924fe798a01285 ] 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 Signed-off-by: Gregory Greenman Link: https://lore.kernel.org/r/20230514120631.b52c9ed5c379.I15290b78e0d966c1b68278263776ca9de841d5fe@changeid Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- drivers/net/wireless/intel/iwlwifi/mvm/rs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c index 0b50b816684a..2be6801d48ac 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c @@ -2692,6 +2692,8 @@ 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; @@ -2706,6 +2708,7 @@ 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,