2 files changed, 61 insertions, 10 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 57ee84d21470..275d901d7e46 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -750,6 +750,10 @@ static void netlink_skb_destructor(struct sk_buff *skb)
 		skb->head = NULL;
 	}
 #endif
+	if (is_vmalloc_addr(skb->head)) {
+		vfree(skb->head);
+		skb->head = NULL;
+	}
 	if (skb->sk != NULL)
 		sock_rfree(skb);
 }
@@ -854,16 +858,23 @@ netlink_unlock_table(void)
 		wake_up(&nl_table_wait);
 }
 
+static bool netlink_compare(struct net *net, struct sock *sk)
+{
+	return net_eq(sock_net(sk), net);
+}
+
 static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
 {
-	struct nl_portid_hash *hash = &nl_table[protocol].hash;
+	struct netlink_table *table = &nl_table[protocol];
+	struct nl_portid_hash *hash = &table->hash;
 	struct hlist_head *head;
 	struct sock *sk;
 
 	read_lock(&nl_table_lock);
 	head = nl_portid_hashfn(hash, portid);
 	sk_for_each(sk, head) {
-		if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->portid == portid)) {
+		if (table->compare(net, sk) &&
+		    (nlk_sk(sk)->portid == portid)) {
 			sock_hold(sk);
 			goto found;
 		}
@@ -976,7 +987,8 @@ netlink_update_listeners(struct sock *sk)
 
 static int netlink_insert(struct sock *sk, struct net *net, u32 portid)
 {
-	struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash;
+	struct netlink_table *table = &nl_table[sk->sk_protocol];
+	struct nl_portid_hash *hash = &table->hash;
 	struct hlist_head *head;
 	int err = -EADDRINUSE;
 	struct sock *osk;
@@ -986,7 +998,8 @@ static int netlink_insert(struct sock *sk, struct net *net, u32 portid)
 	head = nl_portid_hashfn(hash, portid);
 	len = 0;
 	sk_for_each(osk, head) {
-		if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->portid == portid))
+		if (table->compare(net, osk) &&
+		    (nlk_sk(osk)->portid == portid))
 			break;
 		len++;
 	}
@@ -1183,7 +1196,8 @@ static int netlink_autobind(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 	struct net *net = sock_net(sk);
-	struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash;
+	struct netlink_table *table = &nl_table[sk->sk_protocol];
+	struct nl_portid_hash *hash = &table->hash;
 	struct hlist_head *head;
 	struct sock *osk;
 	s32 portid = task_tgid_vnr(current);
@@ -1195,7 +1209,7 @@ retry:
 	netlink_table_grab();
 	head = nl_portid_hashfn(hash, portid);
 	sk_for_each(osk, head) {
-		if (!net_eq(sock_net(osk), net))
+		if (!table->compare(net, osk))
 			continue;
 		if (nlk_sk(osk)->portid == portid) {
 			/* Bind collision, search negative portid values. */
@@ -1420,6 +1434,35 @@ struct sock *netlink_getsockbyfilp(struct file *filp)
 	return sock;
 }
 
+static struct sk_buff *netlink_alloc_large_skb(unsigned int size)
+{
+	struct sk_buff *skb;
+	void *data;
+
+	if (size <= NLMSG_GOODSIZE)
+		return alloc_skb(size, GFP_KERNEL);
+
+	skb = alloc_skb_head(GFP_KERNEL);
+	if (skb == NULL)
+		return NULL;
+
+	data = vmalloc(size);
+	if (data == NULL)
+		goto err;
+
+	skb->head	= data;
+	skb->data	= data;
+	skb_reset_tail_pointer(skb);
+	skb->end	= skb->tail + size;
+	skb->len	= 0;
+	skb->destructor = netlink_skb_destructor;
+
+	return skb;
+err:
+	kfree_skb(skb);
+	return NULL;
+}
+
 /*
  * Attach a skb to a netlink socket.
  * The caller must hold a reference to the destination socket. On error, the
@@ -1510,7 +1553,7 @@ static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
 		return skb;
 
 	delta = skb->end - skb->tail;
-	if (delta * 2 < skb->truesize)
+	if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
 		return skb;
 
 	if (skb_shared(skb)) {
@@ -2096,7 +2139,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	if (len > sk->sk_sndbuf - 32)
 		goto out;
 	err = -ENOBUFS;
-	skb = alloc_skb(len, GFP_KERNEL);
+	skb = netlink_alloc_large_skb(len);
 	if (skb == NULL)
 		goto out;
 
@@ -2285,6 +2328,8 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
 		if (cfg) {
 			nl_table[unit].bind = cfg->bind;
 			nl_table[unit].flags = cfg->flags;
+			if (cfg->compare)
+				nl_table[unit].compare = cfg->compare;
 		}
 		nl_table[unit].registered = 1;
 	} else {
@@ -2707,6 +2752,7 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct sock *s;
 	struct nl_seq_iter *iter;
+	struct net *net;
 	int i, j;
 
 	++*pos;
@@ -2714,11 +2760,12 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	if (v == SEQ_START_TOKEN)
 		return netlink_seq_socket_idx(seq, 0);
 
+	net = seq_file_net(seq);
 	iter = seq->private;
 	s = v;
 	do {
 		s = sk_next(s);
-	} while (s && sock_net(s) != seq_file_net(seq));
+	} while (s && !nl_table[s->sk_protocol].compare(net, s));
 	if (s)
 		return s;
 
@@ -2730,7 +2777,8 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 
 		for (; j <= hash->mask; j++) {
 			s = sk_head(&hash->table[j]);
-			while (s && sock_net(s) != seq_file_net(seq))
+
+			while (s && !nl_table[s->sk_protocol].compare(net, s))
 				s = sk_next(s);
 			if (s) {
 				iter->link = i;
@@ -2923,6 +2971,8 @@ static int __init netlink_proto_init(void)
 		hash->shift = 0;
 		hash->mask = 0;
 		hash->rehash_time = jiffies;
+
+		nl_table[i].compare = netlink_compare;
 	}
 
 	netlink_add_usersock_entry();
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
index ed8522265f4e..eaa88d187cdc 100644
--- a/net/netlink/af_netlink.h
+++ b/net/netlink/af_netlink.h
@@ -73,6 +73,7 @@ struct netlink_table {
 	struct mutex		*cb_mutex;
 	struct module		*module;
 	void			(*bind)(int group);
+	bool			(*compare)(struct net *net, struct sock *sock);
 	int			registered;
 };