linux-kernel - [v2 2/5] NET: nps_enet: TX done race condition

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 20 Aug 2015 08:00:02 +0300
From:	Noam Camus <noamc@...hip.com>
To:	<linux-kernel@...r.kernel.org>, <netdev@...r.kernel.org>
CC:	<davem@...emloft.net>, <Alexey.Brodkin@...opsys.com>,
	<vgupta@...opsys.com>, <talz@...hip.com>,
	Noam Camus <noamc@...hip.com>
Subject: [v2 2/5] NET: nps_enet: TX done race condition

From: Noam Camus <noamc@...hip.com>

We need to set tx_skb pointer before send frame.
If we receive interrupt before we set pointer we will try
to free SKB with wrong pointer.
Now we are sure that SKB pointer will never be NULL during
handling TX done and check is removed.

Signed-off-by: Noam Camus <noamc@...hip.com>
---
 drivers/net/ethernet/ezchip/nps_enet.c |   10 +++-------
 1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ezchip/nps_enet.c b/drivers/net/ethernet/ezchip/nps_enet.c
index 0e652b4..8b25f24 100644
--- a/drivers/net/ethernet/ezchip/nps_enet.c
+++ b/drivers/net/ethernet/ezchip/nps_enet.c
@@ -158,11 +158,7 @@ static void nps_enet_tx_handler(struct net_device *ndev)
 		ndev->stats.tx_bytes += tx_ctrl.nt;
 	}
 
-	if (priv->tx_skb) {
-		dev_kfree_skb(priv->tx_skb);
-		priv->tx_skb = NULL;
-	}
-
+	dev_kfree_skb(priv->tx_skb);
 	priv->tx_packet_sent = false;
 
 	if (netif_queue_stopped(ndev))
@@ -528,10 +524,10 @@ static netdev_tx_t nps_enet_start_xmit(struct sk_buff *skb,
 	/* This driver handles one frame at a time  */
 	netif_stop_queue(ndev);
 
-	nps_enet_send_frame(ndev, skb);
-
 	priv->tx_skb = skb;
 
+	nps_enet_send_frame(ndev, skb);
+
 	return NETDEV_TX_OK;
 }
 
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/