netdev - [PATCH v2] Fix locking in flush

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-next>] [day] [month] [year] [list]

Date:	Tue, 23 Mar 2010 16:39:19 -0700 (PDT)
From:	Tom Herbert <therbert@...gle.com>
To:	davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH v2] Fix locking in flush_backlog

Need to take spinlocks when dequeuing from input_pkt_queue in flush_backlog.
Also, flush_backlog can now be called directly from netdev_run_todo.

Signed-off-by: Tom Herbert <therbert@...gle.com>
---
diff --git a/net/core/dev.c b/net/core/dev.c
diff --git a/net/core/dev.c b/net/core/dev.c
index a03aab4..5e3dc28 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2766,17 +2766,19 @@ int netif_receive_skb(struct sk_buff *skb)
 EXPORT_SYMBOL(netif_receive_skb);
 
 /* Network device is going away, flush any packets still pending  */
-static void flush_backlog(void *arg)
+static void flush_backlog(struct net_device *dev, int cpu)
 {
-	struct net_device *dev = arg;
-	struct softnet_data *queue = &__get_cpu_var(softnet_data);
+	struct softnet_data *queue = &per_cpu(softnet_data, cpu);
 	struct sk_buff *skb, *tmp;
+	unsigned long flags;
 
+	spin_lock_irqsave(&queue->input_pkt_queue.lock, flags);
 	skb_queue_walk_safe(&queue->input_pkt_queue, skb, tmp)
 		if (skb->dev == dev) {
 			__skb_unlink(skb, &queue->input_pkt_queue);
 			kfree_skb(skb);
 		}
+	spin_unlock_irqrestore(&queue->input_pkt_queue.lock, flags);
 }
 
 static int napi_gro_complete(struct sk_buff *skb)
@@ -5545,6 +5547,7 @@ void netdev_run_todo(void)
 	while (!list_empty(&list)) {
 		struct net_device *dev
 			= list_first_entry(&list, struct net_device, todo_list);
+		int i;
 		list_del(&dev->todo_list);
 
 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
@@ -5556,7 +5559,8 @@ void netdev_run_todo(void)
 
 		dev->reg_state = NETREG_UNREGISTERED;
 
-		on_each_cpu(flush_backlog, dev, 1);
+		for_each_online_cpu(i)
+			flush_backlog(dev, i);
 
 		netdev_wait_allrefs(dev);
 
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html