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authorTejun Heo <tj@kernel.org>2012-12-21 17:57:10 -0800
committerTejun Heo <tj@kernel.org>2013-02-09 11:34:19 -0800
commit23663c873154f01220ef679558e1ca110c4c4ca4 (patch)
tree5d142c7485c667e4ff7553267f38893a65b482ef
parentad72b3bea744b4db01c89af0f86f3e8920d354df (diff)
wimax/i2400m: fix i2400m->wake_tx_skb handling
i2400m_net_wake_tx() sets ->wake_tx_skb with the given skb if ->wake_tx_ws is not pending; however, i2400m_wake_tx_work() could have just started execution and haven't fetched -><wake_tx_skb yet. The previous packet will be leaked. Update ->wake_tx_skb handling. * i2400m_net_wake_tx() now tests whether the previous ->wake_tx_skb has been consumed by ->wake_tx_ws instead of testing work_pending(). * i2400m_net_wake_stop() is simplified similarly. It always puts ->wake_tx_skb if non-NULL. * Spurious ->wake_tx_skb dereference outside critical section dropped from i2400m_wake_tx_work(). Only compile tested. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Dan Williams <dcbw@redhat.com> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Cc: linux-wimax@intel.com Cc: wimax@linuxwimax.org
-rw-r--r--drivers/net/wimax/i2400m/netdev.c31
1 files changed, 17 insertions, 14 deletions
diff --git a/drivers/net/wimax/i2400m/netdev.c b/drivers/net/wimax/i2400m/netdev.c
index 1d76ae855f07..530581ca0191 100644
--- a/drivers/net/wimax/i2400m/netdev.c
+++ b/drivers/net/wimax/i2400m/netdev.c
@@ -156,7 +156,7 @@ void i2400m_wake_tx_work(struct work_struct *ws)
struct i2400m *i2400m = container_of(ws, struct i2400m, wake_tx_ws);
struct net_device *net_dev = i2400m->wimax_dev.net_dev;
struct device *dev = i2400m_dev(i2400m);
- struct sk_buff *skb = i2400m->wake_tx_skb;
+ struct sk_buff *skb;
unsigned long flags;
spin_lock_irqsave(&i2400m->tx_lock, flags);
@@ -236,23 +236,26 @@ void i2400m_tx_prep_header(struct sk_buff *skb)
void i2400m_net_wake_stop(struct i2400m *i2400m)
{
struct device *dev = i2400m_dev(i2400m);
+ struct sk_buff *wake_tx_skb;
+ unsigned long flags;
d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
- /* See i2400m_hard_start_xmit(), references are taken there
- * and here we release them if the work was still
- * pending. Note we can't differentiate work not pending vs
- * never scheduled, so the NULL check does that. */
- if (cancel_work_sync(&i2400m->wake_tx_ws) == 0
- && i2400m->wake_tx_skb != NULL) {
- unsigned long flags;
- struct sk_buff *wake_tx_skb;
- spin_lock_irqsave(&i2400m->tx_lock, flags);
- wake_tx_skb = i2400m->wake_tx_skb; /* compat help */
- i2400m->wake_tx_skb = NULL; /* compat help */
- spin_unlock_irqrestore(&i2400m->tx_lock, flags);
+ /*
+ * See i2400m_hard_start_xmit(), references are taken there and
+ * here we release them if the packet was still pending.
+ */
+ cancel_work_sync(&i2400m->wake_tx_ws);
+
+ spin_lock_irqsave(&i2400m->tx_lock, flags);
+ wake_tx_skb = i2400m->wake_tx_skb;
+ i2400m->wake_tx_skb = NULL;
+ spin_unlock_irqrestore(&i2400m->tx_lock, flags);
+
+ if (wake_tx_skb) {
i2400m_put(i2400m);
kfree_skb(wake_tx_skb);
}
+
d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
}
@@ -288,7 +291,7 @@ int i2400m_net_wake_tx(struct i2400m *i2400m, struct net_device *net_dev,
* and if pending, release those resources. */
result = 0;
spin_lock_irqsave(&i2400m->tx_lock, flags);
- if (!work_pending(&i2400m->wake_tx_ws)) {
+ if (!i2400m->wake_tx_skb) {
netif_stop_queue(net_dev);
i2400m_get(i2400m);
i2400m->wake_tx_skb = skb_get(skb); /* transfer ref count */