| Date | Fri, 08 Jun 2012 05:19:06 +0100 | From | Ben Hutchings <> | Subject | [ 26/82] ath9k: fix a use-after-free-bug when ath_tx_setup_buffer() fails |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Felix Fietkau <nbd@openwrt.org>
commit 81357a281dcc454841532c46b30e6f2ba12b73ea upstream.
ath_tx_setup_buffer() can fail if there is no ath_buf left, or if mapping DMA failed. In this case it frees the skb passed to it. If ath_tx_setup_buffer is called from ath_tx_form_aggr, the skb is still linked into the tid buffer list and must be dequeued before being released.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/net/wireless/ath/ath9k/xmit.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)
--- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -64,7 +64,8 @@ static struct ath_buf *ath_tx_setup_buffer(struct ath_softc *sc, struct ath_txq *txq, struct ath_atx_tid *tid, - struct sk_buff *skb); + struct sk_buff *skb, + bool dequeue); enum { MCS_HT20, @@ -761,7 +762,7 @@ fi = get_frame_info(skb); bf = fi->bf; if (!fi->bf) - bf = ath_tx_setup_buffer(sc, txq, tid, skb); + bf = ath_tx_setup_buffer(sc, txq, tid, skb, true); if (!bf) continue; @@ -1669,7 +1670,7 @@ return; } - bf = ath_tx_setup_buffer(sc, txctl->txq, tid, skb); + bf = ath_tx_setup_buffer(sc, txctl->txq, tid, skb, false); if (!bf) return; @@ -1696,7 +1697,7 @@ bf = fi->bf; if (!bf) - bf = ath_tx_setup_buffer(sc, txq, tid, skb); + bf = ath_tx_setup_buffer(sc, txq, tid, skb, false); if (!bf) return; @@ -1761,7 +1762,8 @@ static struct ath_buf *ath_tx_setup_buffer(struct ath_softc *sc, struct ath_txq *txq, struct ath_atx_tid *tid, - struct sk_buff *skb) + struct sk_buff *skb, + bool dequeue) { struct ath_common *common = ath9k_hw_common(sc->sc_ah); struct ath_frame_info *fi = get_frame_info(skb); @@ -1802,6 +1804,8 @@ return bf; error: + if (dequeue) + __skb_unlink(skb, &tid->buf_q); dev_kfree_skb_any(skb); return NULL; } @@ -1833,7 +1837,7 @@ */ ath_tx_send_ampdu(sc, tid, skb, txctl); } else { - bf = ath_tx_setup_buffer(sc, txctl->txq, tid, skb); + bf = ath_tx_setup_buffer(sc, txctl->txq, tid, skb, false); if (!bf) goto out;
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