From 6cf9e995f91e5bbffb2bef85feef490e5b67605d Mon Sep 17 00:00:00 2001 From: Ben Greear Date: Thu, 14 Oct 2010 12:45:30 -0700 Subject: [PATCH] ath9k: Null out references to stale pointers. This doesn't fix any problem that I'm aware of, but should make it harder to add use-after-free type bugs in the future. Signed-off-by: Ben Greear Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath9k/beacon.c | 5 +++++ drivers/net/wireless/ath/ath9k/recv.c | 5 +++++ drivers/net/wireless/ath/ath9k/xmit.c | 6 ++++++ 3 files changed, 16 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c index af8fedda001b..4ed010d4ef96 100644 --- a/drivers/net/wireless/ath/ath9k/beacon.c +++ b/drivers/net/wireless/ath/ath9k/beacon.c @@ -139,6 +139,7 @@ static struct ath_buf *ath_beacon_generate(struct ieee80211_hw *hw, dma_unmap_single(sc->dev, bf->bf_buf_addr, skb->len, DMA_TO_DEVICE); dev_kfree_skb_any(skb); + bf->bf_buf_addr = 0; } /* Get a new beacon from mac80211 */ @@ -167,6 +168,7 @@ static struct ath_buf *ath_beacon_generate(struct ieee80211_hw *hw, if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) { dev_kfree_skb_any(skb); bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; ath_print(common, ATH_DBG_FATAL, "dma_mapping_error on beaconing\n"); return NULL; @@ -255,6 +257,7 @@ int ath_beacon_alloc(struct ath_wiphy *aphy, struct ieee80211_vif *vif) skb->len, DMA_TO_DEVICE); dev_kfree_skb_any(skb); bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; } /* NB: the beacon data buffer must be 32-bit aligned. */ @@ -300,6 +303,7 @@ int ath_beacon_alloc(struct ath_wiphy *aphy, struct ieee80211_vif *vif) if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) { dev_kfree_skb_any(skb); bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; ath_print(common, ATH_DBG_FATAL, "dma_mapping_error on beacon alloc\n"); return -ENOMEM; @@ -326,6 +330,7 @@ void ath_beacon_return(struct ath_softc *sc, struct ath_vif *avp) skb->len, DMA_TO_DEVICE); dev_kfree_skb_any(skb); bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; } list_add_tail(&bf->list, &sc->beacon.bbuf); diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 2e427522672d..fe73fc50082a 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -268,6 +268,7 @@ static int ath_rx_edma_init(struct ath_softc *sc, int nbufs) bf->bf_buf_addr))) { dev_kfree_skb_any(skb); bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; ath_print(common, ATH_DBG_FATAL, "dma_mapping_error() on RX init\n"); error = -ENOMEM; @@ -358,6 +359,7 @@ int ath_rx_init(struct ath_softc *sc, int nbufs) bf->bf_buf_addr))) { dev_kfree_skb_any(skb); bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; ath_print(common, ATH_DBG_FATAL, "dma_mapping_error() on RX init\n"); error = -ENOMEM; @@ -392,6 +394,8 @@ void ath_rx_cleanup(struct ath_softc *sc) common->rx_bufsize, DMA_FROM_DEVICE); dev_kfree_skb(skb); + bf->bf_buf_addr = 0; + bf->bf_mpdu = NULL; } } @@ -1733,6 +1737,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) bf->bf_buf_addr))) { dev_kfree_skb_any(requeue_skb); bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; ath_print(common, ATH_DBG_FATAL, "dma_mapping_error() on RX\n"); ath_rx_send_to_mac80211(hw, sc, skb, rxs); diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c index b053058ae5ea..d077186da870 100644 --- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -1643,6 +1643,7 @@ static int ath_tx_setup_buffer(struct ieee80211_hw *hw, struct ath_buf *bf, skb->len, DMA_TO_DEVICE); if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) { bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; ath_print(ath9k_hw_common(sc->sc_ah), ATH_DBG_FATAL, "dma_mapping_error() on TX\n"); return -ENOMEM; @@ -1912,6 +1913,7 @@ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf, } dma_unmap_single(sc->dev, bf->bf_buf_addr, skb->len, DMA_TO_DEVICE); + bf->bf_buf_addr = 0; if (bf->bf_state.bfs_paprd) { if (time_after(jiffies, @@ -1924,6 +1926,10 @@ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf, ath_debug_stat_tx(sc, txq, bf, ts); ath_tx_complete(sc, skb, bf->aphy, tx_flags); } + /* At this point, skb (bf->bf_mpdu) is consumed...make sure we don't + * accidentally reference it later. + */ + bf->bf_mpdu = NULL; /* * Return the list of ath_buf of this mpdu to free queue -- 2.20.1