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 <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index af8fedd..4ed010d 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -139,6 +139,7 @@
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 @@
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 @@
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 @@
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 @@
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 2e42752..fe73fc5 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -268,6 +268,7 @@
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 @@
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 @@
common->rx_bufsize,
DMA_FROM_DEVICE);
dev_kfree_skb(skb);
+ bf->bf_buf_addr = 0;
+ bf->bf_mpdu = NULL;
}
}
@@ -1733,6 +1737,7 @@
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 b053058..d077186 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1643,6 +1643,7 @@
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 @@
}
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 @@
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