From 6a028d9a26446a937fa5c2eaca9407985ef98add Mon Sep 17 00:00:00 2001 From: Eyal Shapira Date: Sun, 7 Dec 2014 18:18:27 +0200 Subject: [PATCH] iwlwifi: mvm: rs: fix max rate allowed if no rate is allowed In case the rate mask for one of the modulations was zero the max rate idx for that modulation was set to 32 (BITS_PER_LONG). This is bad as it would later lead to an out of bounds access to the expected tpt table. In most cases there was no real effect as the expected tpt was set to 0 and this led to avoiding the modulation effectively. Fix the out of bounds access and explicitly skip the modulation in case there's no rate allowed in it. Signed-off-by: Eyal Shapira Signed-off-by: Emmanuel Grumbach --- drivers/net/wireless/iwlwifi/mvm/rs.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/mvm/rs.c b/drivers/net/wireless/iwlwifi/mvm/rs.c index b9682d7..999efc3 100644 --- a/drivers/net/wireless/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/iwlwifi/mvm/rs.c @@ -1318,6 +1318,13 @@ static void rs_set_stay_in_table(struct iwl_mvm *mvm, u8 is_legacy, lq_sta->visited_columns = 0; } +static inline int rs_get_max_rate_from_mask(unsigned long rate_mask) +{ + if (rate_mask) + return find_last_bit(&rate_mask, BITS_PER_LONG); + return IWL_RATE_INVALID; +} + static int rs_get_max_allowed_rate(struct iwl_lq_sta *lq_sta, const struct rs_tx_column *column) { @@ -1613,8 +1620,12 @@ static enum rs_column rs_get_next_column(struct iwl_mvm *mvm, continue; max_rate = rs_get_max_allowed_rate(lq_sta, next_col); - if (WARN_ON_ONCE(max_rate == IWL_RATE_INVALID)) + if (max_rate == IWL_RATE_INVALID) { + IWL_DEBUG_RATE(mvm, + "Skip column %d: no rate is allowed in this column\n", + next_col_id); continue; + } max_expected_tpt = expected_tpt_tbl[max_rate]; if (tpt >= max_expected_tpt) { @@ -2765,12 +2776,12 @@ void iwl_mvm_rs_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta *sta, if (IWL_MVM_RS_DISABLE_MIMO) lq_sta->active_mimo2_rate = 0; - lq_sta->max_legacy_rate_idx = find_last_bit(&lq_sta->active_legacy_rate, - BITS_PER_LONG); - lq_sta->max_siso_rate_idx = find_last_bit(&lq_sta->active_siso_rate, - BITS_PER_LONG); - lq_sta->max_mimo2_rate_idx = find_last_bit(&lq_sta->active_mimo2_rate, - BITS_PER_LONG); + lq_sta->max_legacy_rate_idx = + rs_get_max_rate_from_mask(lq_sta->active_legacy_rate); + lq_sta->max_siso_rate_idx = + rs_get_max_rate_from_mask(lq_sta->active_siso_rate); + lq_sta->max_mimo2_rate_idx = + rs_get_max_rate_from_mask(lq_sta->active_mimo2_rate); IWL_DEBUG_RATE(mvm, "RATE MASK: LEGACY=%lX SISO=%lX MIMO2=%lX VHT=%d LDPC=%d STBC%d\n", -- 2.7.4