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ath9k: Null out references to stale pointers.

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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 <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Ben Greear 2010-10-14 12:45:30 -07:00 committed by John W. Linville
parent c1739eb3e6
commit 6cf9e995f9
3 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/net/wireless/ath/ath9k/beacon.c
View File

@ -139,6 +139,7 @@ static struct ath_buf *ath_beacon_generate(struct ieee80211_hw *hw,
dma_unmap_single(sc->dev, bf->bf_buf_addr, dma_unmap_single(sc->dev, bf->bf_buf_addr,
skb->len, DMA_TO_DEVICE); skb->len, DMA_TO_DEVICE);
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
bf->bf_buf_addr = 0;
} }
/* Get a new beacon from mac80211 */ /* 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))) { if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) {
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
ath_print(common, ATH_DBG_FATAL, ath_print(common, ATH_DBG_FATAL,
"dma_mapping_error on beaconing\n"); "dma_mapping_error on beaconing\n");
return NULL; return NULL;
@ -255,6 +257,7 @@ int ath_beacon_alloc(struct ath_wiphy *aphy, struct ieee80211_vif *vif)
skb->len, DMA_TO_DEVICE); skb->len, DMA_TO_DEVICE);
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
} }
/* NB: the beacon data buffer must be 32-bit aligned. */ /* 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))) { if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) {
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
ath_print(common, ATH_DBG_FATAL, ath_print(common, ATH_DBG_FATAL,
"dma_mapping_error on beacon alloc\n"); "dma_mapping_error on beacon alloc\n");
return -ENOMEM; return -ENOMEM;
@ -326,6 +330,7 @@ void ath_beacon_return(struct ath_softc *sc, struct ath_vif *avp)
skb->len, DMA_TO_DEVICE); skb->len, DMA_TO_DEVICE);
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
} }
list_add_tail(&bf->list, &sc->beacon.bbuf); list_add_tail(&bf->list, &sc->beacon.bbuf);

5
drivers/net/wireless/ath/ath9k/recv.c
View File

@ -268,6 +268,7 @@ static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
bf->bf_buf_addr))) { bf->bf_buf_addr))) {
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
ath_print(common, ATH_DBG_FATAL, ath_print(common, ATH_DBG_FATAL,
"dma_mapping_error() on RX init\n"); "dma_mapping_error() on RX init\n");
error = -ENOMEM; error = -ENOMEM;
@ -358,6 +359,7 @@ int ath_rx_init(struct ath_softc *sc, int nbufs)
bf->bf_buf_addr))) { bf->bf_buf_addr))) {
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
ath_print(common, ATH_DBG_FATAL, ath_print(common, ATH_DBG_FATAL,
"dma_mapping_error() on RX init\n"); "dma_mapping_error() on RX init\n");
error = -ENOMEM; error = -ENOMEM;
@ -392,6 +394,8 @@ void ath_rx_cleanup(struct ath_softc *sc)
common->rx_bufsize, common->rx_bufsize,
DMA_FROM_DEVICE); DMA_FROM_DEVICE);
dev_kfree_skb(skb); 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))) { bf->bf_buf_addr))) {
dev_kfree_skb_any(requeue_skb); dev_kfree_skb_any(requeue_skb);
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
ath_print(common, ATH_DBG_FATAL, ath_print(common, ATH_DBG_FATAL,
"dma_mapping_error() on RX\n"); "dma_mapping_error() on RX\n");
ath_rx_send_to_mac80211(hw, sc, skb, rxs); ath_rx_send_to_mac80211(hw, sc, skb, rxs);

6
drivers/net/wireless/ath/ath9k/xmit.c
View File

@ -1643,6 +1643,7 @@ static int ath_tx_setup_buffer(struct ieee80211_hw *hw, struct ath_buf *bf,
skb->len, DMA_TO_DEVICE); skb->len, DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) { if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) {
bf->bf_mpdu = NULL; bf->bf_mpdu = NULL;
bf->bf_buf_addr = 0;
ath_print(ath9k_hw_common(sc->sc_ah), ATH_DBG_FATAL, ath_print(ath9k_hw_common(sc->sc_ah), ATH_DBG_FATAL,
"dma_mapping_error() on TX\n"); "dma_mapping_error() on TX\n");
return -ENOMEM; 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); 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 (bf->bf_state.bfs_paprd) {
if (time_after(jiffies, 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_debug_stat_tx(sc, txq, bf, ts);
ath_tx_complete(sc, skb, bf->aphy, tx_flags); 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 * Return the list of ath_buf of this mpdu to free queue