From 5871d2d787bc2fc45e43c9f8ecabdd2db37ad666 Mon Sep 17 00:00:00 2001 From: Sujith Manoharan Date: Wed, 14 Aug 2013 09:11:11 +0530 Subject: [PATCH] ath9k: Discard invalid frames early Frames with invalid or zero length can be discarded early, there is no need to check the crypto bits. Signed-off-by: Sujith Manoharan Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath9k/recv.c | 38 ++++++++++++++++----------- 1 file changed, 22 insertions(+), 16 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 83b3fc57cabb..f8cc2b3b38d9 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -764,7 +764,6 @@ static bool ath9k_rx_accept(struct ath_common *common, bool is_mc, is_valid_tkip, strip_mic, mic_error; struct ath_hw *ah = common->ah; __le16 fc; - u8 rx_status_len = ah->caps.rx_status_len; fc = hdr->frame_control; @@ -786,21 +785,6 @@ static bool ath9k_rx_accept(struct ath_common *common, !test_bit(rx_stats->rs_keyix, common->ccmp_keymap)) rx_stats->rs_status &= ~ATH9K_RXERR_KEYMISS; - if (!rx_stats->rs_datalen) { - RX_STAT_INC(rx_len_err); - return false; - } - - /* - * rs_status follows rs_datalen so if rs_datalen is too large - * we can take a hint that hardware corrupted it, so ignore - * those frames. - */ - if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len)) { - RX_STAT_INC(rx_len_err); - return false; - } - /* Only use error bits from the last fragment */ if (rx_stats->rs_more) return true; @@ -949,10 +933,32 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc, struct ath_common *common = ath9k_hw_common(ah); bool discard_current = sc->rx.discard_next; + /* + * Discard corrupt descriptors which are marked in + * ath_get_next_rx_buf(). + */ sc->rx.discard_next = rx_stats->rs_more; if (discard_current) return -EINVAL; + /* + * Discard zero-length packets. + */ + if (!rx_stats->rs_datalen) { + RX_STAT_INC(rx_len_err); + return -EINVAL; + } + + /* + * rs_status follows rs_datalen so if rs_datalen is too large + * we can take a hint that hardware corrupted it, so ignore + * those frames. + */ + if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) { + RX_STAT_INC(rx_len_err); + return -EINVAL; + } + /* * everything but the rate is checked here, the rate check is done * separately to avoid doing two lookups for a rate for each frame. -- 2.20.1