From a56c14bb21b296fb6d395164ab62ef2e419e5069 Mon Sep 17 00:00:00 2001 From: Shuah Khan Date: Sat, 13 Feb 2021 07:58:47 +0200 Subject: [PATCH] ath9k: fix ath_tx_process_buffer() potential null ptr dereference ath_tx_process_buffer() references ieee80211_find_sta_by_ifaddr() return pointer (sta) outside null check. Fix it by moving the code block under the null check. This problem was found while reviewing code to debug RCU warn from ath10k_wmi_tlv_parse_peer_stats_info() and a subsequent manual audit of other callers of ieee80211_find_sta_by_ifaddr() that don't hold RCU read lock. Signed-off-by: Shuah Khan Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/43ed9abb9e8d7112f3cc168c2f8c489e253635ba.1613090339.git.skhan@linuxfoundation.org --- drivers/net/wireless/ath/ath9k/xmit.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c index e60d473..828b96b 100644 --- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -708,20 +708,24 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq, ath_tx_count_airtime(sc, sta, bf, ts, tid->tidno); if (ts->ts_status & (ATH9K_TXERR_FILT | ATH9K_TXERR_XRETRY)) tid->clear_ps_filter = true; - } - if (!bf_isampdu(bf)) { - if (!flush) { - info = IEEE80211_SKB_CB(bf->bf_mpdu); - memcpy(info->control.rates, bf->rates, - sizeof(info->control.rates)); - ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok); - ath_dynack_sample_tx_ts(sc->sc_ah, bf->bf_mpdu, ts, - sta); + if (!bf_isampdu(bf)) { + if (!flush) { + info = IEEE80211_SKB_CB(bf->bf_mpdu); + memcpy(info->control.rates, bf->rates, + sizeof(info->control.rates)); + ath_tx_rc_status(sc, bf, ts, 1, + txok ? 0 : 1, txok); + ath_dynack_sample_tx_ts(sc->sc_ah, + bf->bf_mpdu, ts, sta); + } + ath_tx_complete_buf(sc, bf, txq, bf_head, sta, + ts, txok); + } else { + ath_tx_complete_aggr(sc, txq, bf, bf_head, sta, + tid, ts, txok); } - ath_tx_complete_buf(sc, bf, txq, bf_head, sta, ts, txok); - } else - ath_tx_complete_aggr(sc, txq, bf, bf_head, sta, tid, ts, txok); + } if (!flush) ath_txq_schedule(sc, txq); -- 2.7.4