[ 48/76] mac80211: use ieee80211_free_txskb to fix possible skb leaks

Greg Kroah-Hartman
2012-10-19T02:49:15Z

From: Felix Fietkau <nbd@openwrt.org>

commit c3e7724b6bc2f25e46c38dbe68f09d71fafeafb8 upstream.

A few places free skbs using dev_kfree_skb even though they're called
after ieee80211_subif_start_xmit might have cloned it for tracking tx
status. Use ieee80211_free_txskb here to prevent skb leaks.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/mac80211/status.c | 4 ++--
net/mac80211/tx.c | 22 ++++++++++++----------
2 files changed, 14 insertions(+), 12 deletions(-)

--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -34,7 +34,7 @@ void ieee80211_tx_status_irqsafe(struct
skb_queue_len(&local->skb_queue_unreliable);
while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
(skb = skb_dequeue(&local->skb_queue_unreliable))) {
- dev_kfree_skb_irq(skb);
+ ieee80211_free_txskb(hw, skb);
tmp--;
I802_DEBUG_INC(local->tx_status_drop);
}
@@ -159,7 +159,7 @@ static void ieee80211_handle_filtered_fr
"dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
skb_queue_len(&sta->tx_filtered[ac]),
!!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
- dev_kfree_skb(skb);
+ ieee80211_free_txskb(&local->hw, skb);
}

static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -354,7 +354,7 @@ static void purge_old_ps_buffers(struct
total += skb_queue_len(&sta->ps_tx_buf[ac]);
if (skb) {
purged++;
- dev_kfree_skb(skb);
+ ieee80211_free_txskb(&local->hw, skb);
break;
}
}
@@ -466,7 +466,7 @@ ieee80211_tx_h_unicast_ps_buf(struct iee
ps_dbg(tx->sdata,
"STA %pM TX buffer for AC %d full - dropping oldest frame\n",
sta->sta.addr, ac);
- dev_kfree_skb(old);
+ ieee80211_free_txskb(&local->hw, old);
} else
tx->local->total_ps_buffered++;

@@ -1103,7 +1103,7 @@ static bool ieee80211_tx_prep_agg(struct
spin_unlock(&tx->sta->lock);

if (purge_skb)
- dev_kfree_skb(purge_skb);
+ ieee80211_free_txskb(&tx->local->hw, purge_skb);
}

/* reset session timer */
@@ -1214,7 +1214,7 @@ static bool ieee80211_tx_frags(struct ie
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
if (WARN_ON_ONCE(q >= local->hw.queues)) {
__skb_unlink(skb, skbs);
- dev_kfree_skb(skb);
+ ieee80211_free_txskb(&local->hw, skb);
continue;
}
#endif
@@ -1356,7 +1356,7 @@ static int invoke_tx_handlers(struct iee
if (unlikely(res == TX_DROP)) {
I802_DEBUG_INC(tx->local->tx_handlers_drop);
if (tx->skb)
- dev_kfree_skb(tx->skb);
+ ieee80211_free_txskb(&tx->local->hw, tx->skb);
else
__skb_queue_purge(&tx->skbs);
return -1;
@@ -1393,7 +1393,7 @@ static bool ieee80211_tx(struct ieee8021
res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);

if (unlikely(res_prepare == TX_DROP)) {
- dev_kfree_skb(skb);
+ ieee80211_free_txskb(&local->hw, skb);
goto out;
} else if (unlikely(res_prepare == TX_QUEUED)) {
goto out;
@@ -1466,7 +1466,7 @@ void ieee80211_xmit(struct ieee80211_sub
headroom = max_t(int, 0, headroom);

if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
- dev_kfree_skb(skb);
+ ieee80211_free_txskb(&local->hw, skb);
rcu_read_unlock();
return;
}
@@ -2060,8 +2060,10 @@ netdev_tx_t ieee80211_subif_start_xmit(s
head_need += IEEE80211_ENCRYPT_HEADROOM;
head_need += local->tx_headroom;
head_need = max_t(int, 0, head_need);
- if (ieee80211_skb_resize(sdata, skb, head_need, true))
- goto fail;
+ if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
+ ieee80211_free_txskb(&local->hw, skb);
+ return NETDEV_TX_OK;
+ }
}

if (encaps_data) {
@@ -2196,7 +2198,7 @@ void ieee80211_tx_pending(unsigned long
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

if (WARN_ON(!info->control.vif)) {
- kfree_skb(skb);
+ ieee80211_free_txskb(&local->hw, skb);
continue;
}