From 8c6e30936a7893a85f6222084f0f26aceb81137a Mon Sep 17 00:00:00 2001 From: Felix Fietkau <nbd@openwrt.org> Date: Fri, 26 Oct 2012 00:31:11 +0200 Subject: [PATCH] ath9k: fix stale pointers potentially causing access to free'd skbs bf->bf_next is only while buffers are chained as part of an A-MPDU in the tx queue. When a tid queue is flushed (e.g. on tearing down an aggregation session), frames can be enqueued again as normal transmission, without bf_next being cleared. This can lead to the old pointer being dereferenced again later. This patch might fix crashes and "Failed to stop TX DMA!" messages. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Cc: stable@vger.kernel.org Signed-off-by: John W. Linville <linville@tuxdriver.com> --- drivers/net/wireless/ath/ath9k/xmit.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c index 378bd70256b2..1ffca7511fa8 100644 --- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -312,6 +312,7 @@ static struct ath_buf *ath_tx_get_buffer(struct ath_softc *sc) } bf = list_first_entry(&sc->tx.txbuf, struct ath_buf, list); + bf->bf_next = NULL; list_del(&bf->list); spin_unlock_bh(&sc->tx.txbuflock); @@ -1774,6 +1775,7 @@ static void ath_tx_send_normal(struct ath_softc *sc, struct ath_txq *txq, list_add_tail(&bf->list, &bf_head); bf->bf_state.bf_type = 0; + bf->bf_next = NULL; bf->bf_lastbf = bf; ath_tx_fill_desc(sc, bf, txq, fi->framelen); ath_tx_txqaddbuf(sc, txq, &bf_head, false); -- GitLab