3 files changed, 74 insertions, 6 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 5c713f2239cc..65f829cfd928 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5247,10 +5247,12 @@ static int dev_new_index(struct net *net)
 
 /* Delayed registration/unregisteration */
 static LIST_HEAD(net_todo_list);
+static DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
 
 static void net_set_todo(struct net_device *dev)
 {
         list_add_tail(&dev->todo_list, &net_todo_list);
+        dev_net(dev)->dev_unreg_count++;
 }
 
 static void rollback_registered_many(struct list_head *head)
@@ -5918,6 +5920,12 @@ void netdev_run_todo(void)
                 if (dev->destructor)
                         dev->destructor(dev);
 
+                /* Report a network device has been unregistered */
+                rtnl_lock();
+                dev_net(dev)->dev_unreg_count--;
+                __rtnl_unlock();
+                wake_up(&netdev_unregistering_wq);
+
                 /* Free network device */
                 kobject_put(&dev->dev.kobj);
         }
@@ -6603,6 +6611,34 @@ static void __net_exit default_device_exit(struct net *net)
         rtnl_unlock();
 }
 
+static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
+{
+        /* Return with the rtnl_lock held when there are no network
+         * devices unregistering in any network namespace in net_list.
+         */
+        struct net *net;
+        bool unregistering;
+        DEFINE_WAIT(wait);
+
+        for (;;) {
+                prepare_to_wait(&netdev_unregistering_wq, &wait,
+                                TASK_UNINTERRUPTIBLE);
+                unregistering = false;
+                rtnl_lock();
+                list_for_each_entry(net, net_list, exit_list) {
+                        if (net->dev_unreg_count > 0) {
+                                unregistering = true;
+                                break;
+                        }
+                }
+                if (!unregistering)
+                        break;
+                __rtnl_unlock();
+                schedule();
+        }
+        finish_wait(&netdev_unregistering_wq, &wait);
+}
+
 static void __net_exit default_device_exit_batch(struct list_head *net_list)
 {
         /* At exit all network devices most be removed from a network
@@ -6614,7 +6650,18 @@ static void __net_exit default_device_exit_batch(struct list_head *net_list)
         struct net *net;
         LIST_HEAD(dev_kill_list);
 
-        rtnl_lock();
+        /* To prevent network device cleanup code from dereferencing
+         * loopback devices or network devices that have been freed
+         * wait here for all pending unregistrations to complete,
+         * before unregistring the loopback device and allowing the
+         * network namespace be freed.
+         *
+         * The netdev todo list containing all network devices
+         * unregistrations that happen in default_device_exit_batch
+         * will run in the rtnl_unlock() at the end of
+         * default_device_exit_batch.
+         */
+        rtnl_lock_unregistering(net_list);
         list_for_each_entry(net, net_list, exit_list) {
                 for_each_netdev_reverse(net, dev) {
                         if (dev->rtnl_link_ops)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 1929af87b260..8d7d0dd72db2 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -154,8 +154,8 @@ ipv6:
         if (poff >= 0) {
                 __be32 *ports, _ports;
 
-                nhoff += poff;
-                ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
+                ports = skb_header_pointer(skb, nhoff + poff,
+                                           sizeof(_ports), &_ports);
                 if (ports)
                         flow->ports = *ports;
         }
diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
index 6a2f13cee86a..3f1ec1586ae1 100644
--- a/net/core/secure_seq.c
+++ b/net/core/secure_seq.c
@@ -10,11 +10,24 @@
 
 #include <net/secure_seq.h>
 
-static u32 net_secret[MD5_MESSAGE_BYTES / 4] ____cacheline_aligned;
+#define NET_SECRET_SIZE (MD5_MESSAGE_BYTES / 4)
 
-void net_secret_init(void)
+static u32 net_secret[NET_SECRET_SIZE] ____cacheline_aligned;
+
+static void net_secret_init(void)
 {
-        get_random_bytes(net_secret, sizeof(net_secret));
+        u32 tmp;
+        int i;
+
+        if (likely(net_secret[0]))
+                return;
+
+        for (i = NET_SECRET_SIZE; i > 0;) {
+                do {
+                        get_random_bytes(&tmp, sizeof(tmp));
+                } while (!tmp);
+                cmpxchg(&net_secret[--i], 0, tmp);
+        }
 }
 
 #ifdef CONFIG_INET
@@ -42,6 +55,7 @@ __u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr,
         u32 hash[MD5_DIGEST_WORDS];
         u32 i;
 
+        net_secret_init();
         memcpy(hash, saddr, 16);
         for (i = 0; i < 4; i++)
                 secret[i] = net_secret[i] + (__force u32)daddr[i];
@@ -63,6 +77,7 @@ u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
         u32 hash[MD5_DIGEST_WORDS];
         u32 i;
 
+        net_secret_init();
         memcpy(hash, saddr, 16);
         for (i = 0; i < 4; i++)
                 secret[i] = net_secret[i] + (__force u32) daddr[i];
@@ -82,6 +97,7 @@ __u32 secure_ip_id(__be32 daddr)
 {
         u32 hash[MD5_DIGEST_WORDS];
 
+        net_secret_init();
         hash[0] = (__force __u32) daddr;
         hash[1] = net_secret[13];
         hash[2] = net_secret[14];
@@ -96,6 +112,7 @@ __u32 secure_ipv6_id(const __be32 daddr[4])
 {
         __u32 hash[4];
 
+        net_secret_init();
         memcpy(hash, daddr, 16);
         md5_transform(hash, net_secret);
 
@@ -107,6 +124,7 @@ __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
 {
         u32 hash[MD5_DIGEST_WORDS];
 
+        net_secret_init();
         hash[0] = (__force u32)saddr;
         hash[1] = (__force u32)daddr;
         hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
@@ -121,6 +139,7 @@ u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
 {
         u32 hash[MD5_DIGEST_WORDS];
 
+        net_secret_init();
         hash[0] = (__force u32)saddr;
         hash[1] = (__force u32)daddr;
         hash[2] = (__force u32)dport ^ net_secret[14];
@@ -140,6 +159,7 @@ u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
         u32 hash[MD5_DIGEST_WORDS];
         u64 seq;
 
+        net_secret_init();
         hash[0] = (__force u32)saddr;
         hash[1] = (__force u32)daddr;
         hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
@@ -164,6 +184,7 @@ u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
         u64 seq;
         u32 i;
 
+        net_secret_init();
         memcpy(hash, saddr, 16);
         for (i = 0; i < 4; i++)
                 secret[i] = net_secret[i] + daddr[i];