2 files changed, 33 insertions, 8 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 582963077877..c421a1f8f0b9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -119,6 +119,7 @@
 #include <linux/err.h>
 #include <linux/ctype.h>
 #include <linux/if_arp.h>
+#include <linux/if_vlan.h>
 
 #include "net-sysfs.h"
 
@@ -1362,6 +1363,29 @@ void netif_device_attach(struct net_device *dev)
 }
 EXPORT_SYMBOL(netif_device_attach);
 
+static bool can_checksum_protocol(unsigned long features, __be16 protocol)
+{
+	return ((features & NETIF_F_GEN_CSUM) ||
+		((features & NETIF_F_IP_CSUM) &&
+		 protocol == htons(ETH_P_IP)) ||
+		((features & NETIF_F_IPV6_CSUM) &&
+		 protocol == htons(ETH_P_IPV6)));
+}
+
+static bool dev_can_checksum(struct net_device *dev, struct sk_buff *skb)
+{
+	if (can_checksum_protocol(dev->features, skb->protocol))
+		return true;
+
+	if (skb->protocol == htons(ETH_P_8021Q)) {
+		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
+		if (can_checksum_protocol(dev->features & dev->vlan_features,
+					  veh->h_vlan_encapsulated_proto))
+			return true;
+	}
+
+	return false;
+}
 
 /*
  * Invalidate hardware checksum when packet is to be mangled, and
@@ -1640,14 +1664,8 @@ int dev_queue_xmit(struct sk_buff *skb)
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		skb_set_transport_header(skb, skb->csum_start -
 					      skb_headroom(skb));
-
-		if (!(dev->features & NETIF_F_GEN_CSUM) &&
-		    !((dev->features & NETIF_F_IP_CSUM) &&
-		      skb->protocol == htons(ETH_P_IP)) &&
-		    !((dev->features & NETIF_F_IPV6_CSUM) &&
-		      skb->protocol == htons(ETH_P_IPV6)))
-			if (skb_checksum_help(skb))
-				goto out_kfree_skb;
+		if (!dev_can_checksum(dev, skb) && skb_checksum_help(skb))
+			goto out_kfree_skb;
 	}
 
 gso:
@@ -2059,6 +2077,10 @@ int netif_receive_skb(struct sk_buff *skb)
 
 	rcu_read_lock();
 
+	/* Don't receive packets in an exiting network namespace */
+	if (!net_alive(dev_net(skb->dev)))
+		goto out;
+
 #ifdef CONFIG_NET_CLS_ACT
 	if (skb->tc_verd & TC_NCLS) {
 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 72b4c184dd84..7c52fe277b62 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -140,6 +140,9 @@ static void cleanup_net(struct work_struct *work)
 	struct pernet_operations *ops;
 	struct net *net;
 
+	/* Be very certain incoming network packets will not find us */
+	rcu_barrier();
+
 	net = container_of(work, struct net, work);
 
 	mutex_lock(&net_mutex);