[ 34/48] be2net: fix a race in be_xmit()

[Ben Hutchings]

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit cd8f76c0a0c6fce0b2cf23c9bd0123f91453f46d ]

As soon as hardware is notified of a transmit, we no longer can assume
skb can be dereferenced, as TX completion might have freed the packet.

Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Sathya Perla <sathya.perla@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/emulex/benet/be_main.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index bf266a0..36c7c4e 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -696,6 +696,8 @@ static netdev_tx_t be_xmit(struct sk_buff *skb,
 
 	copied = make_tx_wrbs(adapter, txq, skb, wrb_cnt, dummy_wrb);
 	if (copied) {
+		int gso_segs = skb_shinfo(skb)->gso_segs;
+
 		/* record the sent skb in the sent_skb table */
 		BUG_ON(txo->sent_skb_list[start]);
 		txo->sent_skb_list[start] = skb;
@@ -713,8 +715,7 @@ static netdev_tx_t be_xmit(struct sk_buff *skb,
 
 		be_txq_notify(adapter, txq->id, wrb_cnt);
 
-		be_tx_stats_update(txo, wrb_cnt, copied,
-				skb_shinfo(skb)->gso_segs, stopped);
+		be_tx_stats_update(txo, wrb_cnt, copied, gso_segs, stopped);
 	} else {
 		txq->head = start;
 		dev_kfree_skb_any(skb);


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