Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

Pablo Neira Ayuso says:

====================
The following patchset contains Netfilter/IPVS fixes for your net
tree, they are:

* Fix BUG_ON splat due to malformed TCP packets seen by synproxy, from
  Patrick McHardy.

* Fix possible weight overflow in lblc and lblcr schedulers due to
  32-bits arithmetics, from Simon Kirby.

* Fix possible memory access race in the lblc and lblcr schedulers,
  introduced when it was converted to use RCU, two patches from
  Julian Anastasov.

* Fix hard dependency on CPU 0 when reading per-cpu stats in the
  rate estimator, from Julian Anastasov.

* Fix race that may lead to object use after release, when invoking
  ipvsadm -C && ipvsadm -R, introduced when adding RCU, from Julian
  Anastasov.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip_vs.h

@@ -723,8 +723,6 @@ struct ip_vs_dest_dst {
 	struct rcu_head		rcu_head;
 };
 
-/* In grace period after removing */
-#define IP_VS_DEST_STATE_REMOVING	0x01
 /*
  *	The real server destination forwarding entry
  *	with ip address, port number, and so on.
@@ -742,7 +740,7 @@ struct ip_vs_dest {
 
 	atomic_t		refcnt;		/* reference counter */
 	struct ip_vs_stats      stats;          /* statistics */
-	unsigned long		state;		/* state flags */
+	unsigned long		idle_start;	/* start time, jiffies */
 
 	/* connection counters and thresholds */
 	atomic_t		activeconns;	/* active connections */
@@ -756,14 +754,13 @@ struct ip_vs_dest {
 	struct ip_vs_dest_dst __rcu *dest_dst;	/* cached dst info */
 
 	/* for virtual service */
-	struct ip_vs_service	*svc;		/* service it belongs to */
+	struct ip_vs_service __rcu *svc;	/* service it belongs to */
 	__u16			protocol;	/* which protocol (TCP/UDP) */
 	__be16			vport;		/* virtual port number */
 	union nf_inet_addr	vaddr;		/* virtual IP address */
 	__u32			vfwmark;	/* firewall mark of service */
 
 	struct list_head	t_list;		/* in dest_trash */
-	struct rcu_head		rcu_head;
 	unsigned int		in_rs_table:1;	/* we are in rs_table */
 };
 
@@ -1649,7 +1646,7 @@ static inline void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp)
 /* CONFIG_IP_VS_NFCT */
 #endif
 
-static inline unsigned int
+static inline int
 ip_vs_dest_conn_overhead(struct ip_vs_dest *dest)
 {
 	/*

include/net/netfilter/nf_conntrack_synproxy.h

@@ -56,7 +56,7 @@ struct synproxy_options {
 
 struct tcphdr;
 struct xt_synproxy_info;
-extern void synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
+extern bool synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
 				   const struct tcphdr *th,
 				   struct synproxy_options *opts);
 extern unsigned int synproxy_options_size(const struct synproxy_options *opts);

net/ipv4/netfilter/ipt_SYNPROXY.c

@@ -267,7 +267,8 @@ synproxy_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 	if (th == NULL)
 		return NF_DROP;
 
-	synproxy_parse_options(skb, par->thoff, th, &opts);
+	if (!synproxy_parse_options(skb, par->thoff, th, &opts))
+		return NF_DROP;
 
 	if (th->syn && !(th->ack || th->fin || th->rst)) {
 		/* Initial SYN from client */
@@ -350,7 +351,8 @@ static unsigned int ipv4_synproxy_hook(unsigned int hooknum,
 
 		/* fall through */
 	case TCP_CONNTRACK_SYN_SENT:
-		synproxy_parse_options(skb, thoff, th, &opts);
+		if (!synproxy_parse_options(skb, thoff, th, &opts))
+			return NF_DROP;
 
 		if (!th->syn && th->ack &&
 		    CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) {
@@ -373,7 +375,9 @@ static unsigned int ipv4_synproxy_hook(unsigned int hooknum,
 		if (!th->syn || !th->ack)
 			break;
 
-		synproxy_parse_options(skb, thoff, th, &opts);
+		if (!synproxy_parse_options(skb, thoff, th, &opts))
+			return NF_DROP;
+
 		if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP)
 			synproxy->tsoff = opts.tsval - synproxy->its;
 

net/ipv6/netfilter/ip6t_SYNPROXY.c

@@ -282,7 +282,8 @@ synproxy_tg6(struct sk_buff *skb, const struct xt_action_param *par)
 	if (th == NULL)
 		return NF_DROP;
 
-	synproxy_parse_options(skb, par->thoff, th, &opts);
+	if (!synproxy_parse_options(skb, par->thoff, th, &opts))
+		return NF_DROP;
 
 	if (th->syn && !(th->ack || th->fin || th->rst)) {
 		/* Initial SYN from client */
@@ -372,7 +373,8 @@ static unsigned int ipv6_synproxy_hook(unsigned int hooknum,
 
 		/* fall through */
 	case TCP_CONNTRACK_SYN_SENT:
-		synproxy_parse_options(skb, thoff, th, &opts);
+		if (!synproxy_parse_options(skb, thoff, th, &opts))
+			return NF_DROP;
 
 		if (!th->syn && th->ack &&
 		    CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) {
@@ -395,7 +397,9 @@ static unsigned int ipv6_synproxy_hook(unsigned int hooknum,
 		if (!th->syn || !th->ack)
 			break;
 
-		synproxy_parse_options(skb, thoff, th, &opts);
+		if (!synproxy_parse_options(skb, thoff, th, &opts))
+			return NF_DROP;
+
 		if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP)
 			synproxy->tsoff = opts.tsval - synproxy->its;
 

net/netfilter/ipvs/ip_vs_core.c

@@ -116,6 +116,7 @@ ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 
 	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
 		struct ip_vs_cpu_stats *s;
+		struct ip_vs_service *svc;
 
 		s = this_cpu_ptr(dest->stats.cpustats);
 		s->ustats.inpkts++;
@@ -123,11 +124,14 @@ ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 		s->ustats.inbytes += skb->len;
 		u64_stats_update_end(&s->syncp);
 
-		s = this_cpu_ptr(dest->svc->stats.cpustats);
+		rcu_read_lock();
+		svc = rcu_dereference(dest->svc);
+		s = this_cpu_ptr(svc->stats.cpustats);
 		s->ustats.inpkts++;
 		u64_stats_update_begin(&s->syncp);
 		s->ustats.inbytes += skb->len;
 		u64_stats_update_end(&s->syncp);
+		rcu_read_unlock();
 
 		s = this_cpu_ptr(ipvs->tot_stats.cpustats);
 		s->ustats.inpkts++;
@@ -146,6 +150,7 @@ ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 
 	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
 		struct ip_vs_cpu_stats *s;
+		struct ip_vs_service *svc;
 
 		s = this_cpu_ptr(dest->stats.cpustats);
 		s->ustats.outpkts++;
@@ -153,11 +158,14 @@ ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 		s->ustats.outbytes += skb->len;
 		u64_stats_update_end(&s->syncp);
 
-		s = this_cpu_ptr(dest->svc->stats.cpustats);
+		rcu_read_lock();
+		svc = rcu_dereference(dest->svc);
+		s = this_cpu_ptr(svc->stats.cpustats);
 		s->ustats.outpkts++;
 		u64_stats_update_begin(&s->syncp);
 		s->ustats.outbytes += skb->len;
 		u64_stats_update_end(&s->syncp);
+		rcu_read_unlock();
 
 		s = this_cpu_ptr(ipvs->tot_stats.cpustats);
 		s->ustats.outpkts++;

net/netfilter/ipvs/ip_vs_ctl.c

@@ -460,7 +460,7 @@ static inline void
 __ip_vs_bind_svc(struct ip_vs_dest *dest, struct ip_vs_service *svc)
 {
 	atomic_inc(&svc->refcnt);
-	dest->svc = svc;
+	rcu_assign_pointer(dest->svc, svc);
 }
 
 static void ip_vs_service_free(struct ip_vs_service *svc)
@@ -470,18 +470,25 @@ static void ip_vs_service_free(struct ip_vs_service *svc)
 	kfree(svc);
 }
 
-static void
+static void ip_vs_service_rcu_free(struct rcu_head *head)
-__ip_vs_unbind_svc(struct ip_vs_dest *dest)
 {
-	struct ip_vs_service *svc = dest->svc;
+	struct ip_vs_service *svc;
 
-	dest->svc = NULL;
+	svc = container_of(head, struct ip_vs_service, rcu_head);
+	ip_vs_service_free(svc);
+}
+
+static void __ip_vs_svc_put(struct ip_vs_service *svc, bool do_delay)
+{
 	if (atomic_dec_and_test(&svc->refcnt)) {
 		IP_VS_DBG_BUF(3, "Removing service %u/%s:%u\n",
 			      svc->fwmark,
 			      IP_VS_DBG_ADDR(svc->af, &svc->addr),
 			      ntohs(svc->port));
-		ip_vs_service_free(svc);
+		if (do_delay)
+			call_rcu(&svc->rcu_head, ip_vs_service_rcu_free);
+		else
+			ip_vs_service_free(svc);
 	}
 }
 
@@ -667,11 +674,6 @@ ip_vs_trash_get_dest(struct ip_vs_service *svc, const union nf_inet_addr *daddr,
 			      IP_VS_DBG_ADDR(svc->af, &dest->addr),
 			      ntohs(dest->port),
 			      atomic_read(&dest->refcnt));
-		/* We can not reuse dest while in grace period
-		 * because conns still can use dest->svc
-		 */
-		if (test_bit(IP_VS_DEST_STATE_REMOVING, &dest->state))
-			continue;
 		if (dest->af == svc->af &&
 		    ip_vs_addr_equal(svc->af, &dest->addr, daddr) &&
 		    dest->port == dport &&
@@ -697,8 +699,10 @@ out:
 
 static void ip_vs_dest_free(struct ip_vs_dest *dest)
 {
+	struct ip_vs_service *svc = rcu_dereference_protected(dest->svc, 1);
+
 	__ip_vs_dst_cache_reset(dest);
-	__ip_vs_unbind_svc(dest);
+	__ip_vs_svc_put(svc, false);
 	free_percpu(dest->stats.cpustats);
 	kfree(dest);
 }
@@ -771,6 +775,7 @@ __ip_vs_update_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest,
 		    struct ip_vs_dest_user_kern *udest, int add)
 {
 	struct netns_ipvs *ipvs = net_ipvs(svc->net);
+	struct ip_vs_service *old_svc;
 	struct ip_vs_scheduler *sched;
 	int conn_flags;
 
@@ -792,13 +797,14 @@ __ip_vs_update_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest,
 	atomic_set(&dest->conn_flags, conn_flags);
 
 	/* bind the service */
-	if (!dest->svc) {
+	old_svc = rcu_dereference_protected(dest->svc, 1);
+	if (!old_svc) {
 		__ip_vs_bind_svc(dest, svc);
 	} else {
-		if (dest->svc != svc) {
+		if (old_svc != svc) {
-			__ip_vs_unbind_svc(dest);
 			ip_vs_zero_stats(&dest->stats);
 			__ip_vs_bind_svc(dest, svc);
+			__ip_vs_svc_put(old_svc, true);
 		}
 	}
 
@@ -998,16 +1004,6 @@ ip_vs_edit_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest)
 	return 0;
 }
 
-static void ip_vs_dest_wait_readers(struct rcu_head *head)
-{
-	struct ip_vs_dest *dest = container_of(head, struct ip_vs_dest,
-					       rcu_head);
-
-	/* End of grace period after unlinking */
-	clear_bit(IP_VS_DEST_STATE_REMOVING, &dest->state);
-}
-
-
 /*
  *	Delete a destination (must be already unlinked from the service)
  */
@@ -1023,20 +1019,16 @@ static void __ip_vs_del_dest(struct net *net, struct ip_vs_dest *dest,
 	 */
 	ip_vs_rs_unhash(dest);
 
-	if (!cleanup) {
-		set_bit(IP_VS_DEST_STATE_REMOVING, &dest->state);
-		call_rcu(&dest->rcu_head, ip_vs_dest_wait_readers);
-	}
-
 	spin_lock_bh(&ipvs->dest_trash_lock);
 	IP_VS_DBG_BUF(3, "Moving dest %s:%u into trash, dest->refcnt=%d\n",
 		      IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port),
 		      atomic_read(&dest->refcnt));
 	if (list_empty(&ipvs->dest_trash) && !cleanup)
 		mod_timer(&ipvs->dest_trash_timer,
-			  jiffies + IP_VS_DEST_TRASH_PERIOD);
+			  jiffies + (IP_VS_DEST_TRASH_PERIOD >> 1));
 	/* dest lives in trash without reference */
 	list_add(&dest->t_list, &ipvs->dest_trash);
+	dest->idle_start = 0;
 	spin_unlock_bh(&ipvs->dest_trash_lock);
 	ip_vs_dest_put(dest);
 }
@@ -1108,24 +1100,30 @@ static void ip_vs_dest_trash_expire(unsigned long data)
 	struct net *net = (struct net *) data;
 	struct netns_ipvs *ipvs = net_ipvs(net);
 	struct ip_vs_dest *dest, *next;
+	unsigned long now = jiffies;
 
 	spin_lock(&ipvs->dest_trash_lock);
 	list_for_each_entry_safe(dest, next, &ipvs->dest_trash, t_list) {
-		/* Skip if dest is in grace period */
-		if (test_bit(IP_VS_DEST_STATE_REMOVING, &dest->state))
-			continue;
 		if (atomic_read(&dest->refcnt) > 0)
 			continue;
+		if (dest->idle_start) {
+			if (time_before(now, dest->idle_start +
+					     IP_VS_DEST_TRASH_PERIOD))
+				continue;
+		} else {
+			dest->idle_start = max(1UL, now);
+			continue;
+		}
 		IP_VS_DBG_BUF(3, "Removing destination %u/%s:%u from trash\n",
 			      dest->vfwmark,
-			      IP_VS_DBG_ADDR(dest->svc->af, &dest->addr),
+			      IP_VS_DBG_ADDR(dest->af, &dest->addr),
 			      ntohs(dest->port));
 		list_del(&dest->t_list);
 		ip_vs_dest_free(dest);
 	}
 	if (!list_empty(&ipvs->dest_trash))
 		mod_timer(&ipvs->dest_trash_timer,
-			  jiffies + IP_VS_DEST_TRASH_PERIOD);
+			  jiffies + (IP_VS_DEST_TRASH_PERIOD >> 1));
 	spin_unlock(&ipvs->dest_trash_lock);
 }
 
@@ -1320,14 +1318,6 @@ out:
 	return ret;
 }
 
-static void ip_vs_service_rcu_free(struct rcu_head *head)
-{
-	struct ip_vs_service *svc;
-
-	svc = container_of(head, struct ip_vs_service, rcu_head);
-	ip_vs_service_free(svc);
-}
-
 /*
  *	Delete a service from the service list
  *	- The service must be unlinked, unlocked and not referenced!
@@ -1376,13 +1366,7 @@ static void __ip_vs_del_service(struct ip_vs_service *svc, bool cleanup)
 	/*
 	 *    Free the service if nobody refers to it
 	 */
-	if (atomic_dec_and_test(&svc->refcnt)) {
+	__ip_vs_svc_put(svc, true);
-		IP_VS_DBG_BUF(3, "Removing service %u/%s:%u\n",
-			      svc->fwmark,
-			      IP_VS_DBG_ADDR(svc->af, &svc->addr),
-			      ntohs(svc->port));
-		call_rcu(&svc->rcu_head, ip_vs_service_rcu_free);
-	}
 
 	/* decrease the module use count */
 	ip_vs_use_count_dec();

net/netfilter/ipvs/ip_vs_est.c

@@ -59,12 +59,13 @@ static void ip_vs_read_cpu_stats(struct ip_vs_stats_user *sum,
 				 struct ip_vs_cpu_stats __percpu *stats)
 {
 	int i;
+	bool add = false;
 
 	for_each_possible_cpu(i) {
 		struct ip_vs_cpu_stats *s = per_cpu_ptr(stats, i);
 		unsigned int start;
 		__u64 inbytes, outbytes;
-		if (i) {
+		if (add) {
 			sum->conns += s->ustats.conns;
 			sum->inpkts += s->ustats.inpkts;
 			sum->outpkts += s->ustats.outpkts;
@@ -76,6 +77,7 @@ static void ip_vs_read_cpu_stats(struct ip_vs_stats_user *sum,
 			sum->inbytes += inbytes;
 			sum->outbytes += outbytes;
 		} else {
+			add = true;
 			sum->conns = s->ustats.conns;
 			sum->inpkts = s->ustats.inpkts;
 			sum->outpkts = s->ustats.outpkts;

net/netfilter/ipvs/ip_vs_lblc.c

@@ -93,7 +93,7 @@ struct ip_vs_lblc_entry {
 	struct hlist_node	list;
 	int			af;		/* address family */
 	union nf_inet_addr      addr;           /* destination IP address */
-	struct ip_vs_dest __rcu	*dest;          /* real server (cache) */
+	struct ip_vs_dest	*dest;          /* real server (cache) */
 	unsigned long           lastuse;        /* last used time */
 	struct rcu_head		rcu_head;
 };
@@ -130,20 +130,21 @@ static struct ctl_table vs_vars_table[] = {
 };
 #endif
 
-static inline void ip_vs_lblc_free(struct ip_vs_lblc_entry *en)
+static void ip_vs_lblc_rcu_free(struct rcu_head *head)
 {
-	struct ip_vs_dest *dest;
+	struct ip_vs_lblc_entry *en = container_of(head,
+						   struct ip_vs_lblc_entry,
+						   rcu_head);
 
-	hlist_del_rcu(&en->list);
+	ip_vs_dest_put(en->dest);
-	/*
+	kfree(en);
-	 * We don't kfree dest because it is referred either by its service
-	 * or the trash dest list.
-	 */
-	dest = rcu_dereference_protected(en->dest, 1);
-	ip_vs_dest_put(dest);
-	kfree_rcu(en, rcu_head);
 }
 
+static inline void ip_vs_lblc_del(struct ip_vs_lblc_entry *en)
+{
+	hlist_del_rcu(&en->list);
+	call_rcu(&en->rcu_head, ip_vs_lblc_rcu_free);
+}
 
 /*
  *	Returns hash value for IPVS LBLC entry
@@ -203,30 +204,23 @@ ip_vs_lblc_new(struct ip_vs_lblc_table *tbl, const union nf_inet_addr *daddr,
 	struct ip_vs_lblc_entry *en;
 
 	en = ip_vs_lblc_get(dest->af, tbl, daddr);
-	if (!en) {
+	if (en) {
-		en = kmalloc(sizeof(*en), GFP_ATOMIC);
+		if (en->dest == dest)
-		if (!en)
+			return en;
-			return NULL;
+		ip_vs_lblc_del(en);
-
-		en->af = dest->af;
-		ip_vs_addr_copy(dest->af, &en->addr, daddr);
-		en->lastuse = jiffies;
-
-		ip_vs_dest_hold(dest);
-		RCU_INIT_POINTER(en->dest, dest);
-
-		ip_vs_lblc_hash(tbl, en);
-	} else {
-		struct ip_vs_dest *old_dest;
-
-		old_dest = rcu_dereference_protected(en->dest, 1);
-		if (old_dest != dest) {
-			ip_vs_dest_put(old_dest);
-			ip_vs_dest_hold(dest);
-			/* No ordering constraints for refcnt */
-			RCU_INIT_POINTER(en->dest, dest);
-		}
 	}
+	en = kmalloc(sizeof(*en), GFP_ATOMIC);
+	if (!en)
+		return NULL;
+
+	en->af = dest->af;
+	ip_vs_addr_copy(dest->af, &en->addr, daddr);
+	en->lastuse = jiffies;
+
+	ip_vs_dest_hold(dest);
+	en->dest = dest;
+
+	ip_vs_lblc_hash(tbl, en);
 
 	return en;
 }
@@ -246,7 +240,7 @@ static void ip_vs_lblc_flush(struct ip_vs_service *svc)
 	tbl->dead = 1;
 	for (i=0; i<IP_VS_LBLC_TAB_SIZE; i++) {
 		hlist_for_each_entry_safe(en, next, &tbl->bucket[i], list) {
-			ip_vs_lblc_free(en);
+			ip_vs_lblc_del(en);
 			atomic_dec(&tbl->entries);
 		}
 	}
@@ -281,7 +275,7 @@ static inline void ip_vs_lblc_full_check(struct ip_vs_service *svc)
 					sysctl_lblc_expiration(svc)))
 				continue;
 
-			ip_vs_lblc_free(en);
+			ip_vs_lblc_del(en);
 			atomic_dec(&tbl->entries);
 		}
 		spin_unlock(&svc->sched_lock);
@@ -335,7 +329,7 @@ static void ip_vs_lblc_check_expire(unsigned long data)
 			if (time_before(now, en->lastuse + ENTRY_TIMEOUT))
 				continue;
 
-			ip_vs_lblc_free(en);
+			ip_vs_lblc_del(en);
 			atomic_dec(&tbl->entries);
 			goal--;
 		}
@@ -443,8 +437,8 @@ __ip_vs_lblc_schedule(struct ip_vs_service *svc)
 			continue;
 
 		doh = ip_vs_dest_conn_overhead(dest);
-		if (loh * atomic_read(&dest->weight) >
+		if ((__s64)loh * atomic_read(&dest->weight) >
-		    doh * atomic_read(&least->weight)) {
+		    (__s64)doh * atomic_read(&least->weight)) {
 			least = dest;
 			loh = doh;
 		}
@@ -511,7 +505,7 @@ ip_vs_lblc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		 * free up entries from the trash at any time.
 		 */
 
-		dest = rcu_dereference(en->dest);
+		dest = en->dest;
 		if ((dest->flags & IP_VS_DEST_F_AVAILABLE) &&
 		    atomic_read(&dest->weight) > 0 && !is_overloaded(dest, svc))
 			goto out;
@@ -631,7 +625,7 @@ static void __exit ip_vs_lblc_cleanup(void)
 {
 	unregister_ip_vs_scheduler(&ip_vs_lblc_scheduler);
 	unregister_pernet_subsys(&ip_vs_lblc_ops);
-	synchronize_rcu();
+	rcu_barrier();
 }
 
 

net/netfilter/ipvs/ip_vs_lblcr.c

@@ -89,7 +89,7 @@
  */
 struct ip_vs_dest_set_elem {
 	struct list_head	list;          /* list link */
-	struct ip_vs_dest __rcu *dest;         /* destination server */
+	struct ip_vs_dest	*dest;		/* destination server */
 	struct rcu_head		rcu_head;
 };
 
@@ -107,11 +107,7 @@ static void ip_vs_dest_set_insert(struct ip_vs_dest_set *set,
 
 	if (check) {
 		list_for_each_entry(e, &set->list, list) {
-			struct ip_vs_dest *d;
+			if (e->dest == dest)
-
-			d = rcu_dereference_protected(e->dest, 1);
-			if (d == dest)
-				/* already existed */
 				return;
 		}
 	}
@@ -121,7 +117,7 @@ static void ip_vs_dest_set_insert(struct ip_vs_dest_set *set,
 		return;
 
 	ip_vs_dest_hold(dest);
-	RCU_INIT_POINTER(e->dest, dest);
+	e->dest = dest;
 
 	list_add_rcu(&e->list, &set->list);
 	atomic_inc(&set->size);
@@ -129,22 +125,27 @@ static void ip_vs_dest_set_insert(struct ip_vs_dest_set *set,
 	set->lastmod = jiffies;
 }
 
+static void ip_vs_lblcr_elem_rcu_free(struct rcu_head *head)
+{
+	struct ip_vs_dest_set_elem *e;
+
+	e = container_of(head, struct ip_vs_dest_set_elem, rcu_head);
+	ip_vs_dest_put(e->dest);
+	kfree(e);
+}
+
 static void
 ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
 {
 	struct ip_vs_dest_set_elem *e;
 
 	list_for_each_entry(e, &set->list, list) {
-		struct ip_vs_dest *d;
+		if (e->dest == dest) {
-
-		d = rcu_dereference_protected(e->dest, 1);
-		if (d == dest) {
 			/* HIT */
 			atomic_dec(&set->size);
 			set->lastmod = jiffies;
-			ip_vs_dest_put(dest);
 			list_del_rcu(&e->list);
-			kfree_rcu(e, rcu_head);
+			call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free);
 			break;
 		}
 	}
@@ -155,16 +156,8 @@ static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set)
 	struct ip_vs_dest_set_elem *e, *ep;
 
 	list_for_each_entry_safe(e, ep, &set->list, list) {
-		struct ip_vs_dest *d;
-
-		d = rcu_dereference_protected(e->dest, 1);
-		/*
-		 * We don't kfree dest because it is referred either
-		 * by its service or by the trash dest list.
-		 */
-		ip_vs_dest_put(d);
 		list_del_rcu(&e->list);
-		kfree_rcu(e, rcu_head);
+		call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free);
 	}
 }
 
@@ -175,12 +168,9 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
 	struct ip_vs_dest *dest, *least;
 	int loh, doh;
 
-	if (set == NULL)
-		return NULL;
-
 	/* select the first destination server, whose weight > 0 */
 	list_for_each_entry_rcu(e, &set->list, list) {
-		least = rcu_dereference(e->dest);
+		least = e->dest;
 		if (least->flags & IP_VS_DEST_F_OVERLOAD)
 			continue;
 
@@ -195,13 +185,13 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
 	/* find the destination with the weighted least load */
   nextstage:
 	list_for_each_entry_continue_rcu(e, &set->list, list) {
-		dest = rcu_dereference(e->dest);
+		dest = e->dest;
 		if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 			continue;
 
 		doh = ip_vs_dest_conn_overhead(dest);
-		if ((loh * atomic_read(&dest->weight) >
+		if (((__s64)loh * atomic_read(&dest->weight) >
-		     doh * atomic_read(&least->weight))
+		     (__s64)doh * atomic_read(&least->weight))
 		    && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
 			least = dest;
 			loh = doh;
@@ -232,7 +222,7 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
 
 	/* select the first destination server, whose weight > 0 */
 	list_for_each_entry(e, &set->list, list) {
-		most = rcu_dereference_protected(e->dest, 1);
+		most = e->dest;
 		if (atomic_read(&most->weight) > 0) {
 			moh = ip_vs_dest_conn_overhead(most);
 			goto nextstage;
@@ -243,11 +233,11 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
 	/* find the destination with the weighted most load */
   nextstage:
 	list_for_each_entry_continue(e, &set->list, list) {
-		dest = rcu_dereference_protected(e->dest, 1);
+		dest = e->dest;
 		doh = ip_vs_dest_conn_overhead(dest);
 		/* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */
-		if ((moh * atomic_read(&dest->weight) <
+		if (((__s64)moh * atomic_read(&dest->weight) <
-		     doh * atomic_read(&most->weight))
+		     (__s64)doh * atomic_read(&most->weight))
 		    && (atomic_read(&dest->weight) > 0)) {
 			most = dest;
 			moh = doh;
@@ -611,8 +601,8 @@ __ip_vs_lblcr_schedule(struct ip_vs_service *svc)
 			continue;
 
 		doh = ip_vs_dest_conn_overhead(dest);
-		if (loh * atomic_read(&dest->weight) >
+		if ((__s64)loh * atomic_read(&dest->weight) >
-		    doh * atomic_read(&least->weight)) {
+		    (__s64)doh * atomic_read(&least->weight)) {
 			least = dest;
 			loh = doh;
 		}
@@ -819,7 +809,7 @@ static void __exit ip_vs_lblcr_cleanup(void)
 {
 	unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
 	unregister_pernet_subsys(&ip_vs_lblcr_ops);
-	synchronize_rcu();
+	rcu_barrier();
 }
 
 

net/netfilter/ipvs/ip_vs_nq.c

@@ -40,7 +40,7 @@
 #include <net/ip_vs.h>
 
 
-static inline unsigned int
+static inline int
 ip_vs_nq_dest_overhead(struct ip_vs_dest *dest)
 {
 	/*
@@ -59,7 +59,7 @@ ip_vs_nq_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		  struct ip_vs_iphdr *iph)
 {
 	struct ip_vs_dest *dest, *least = NULL;
-	unsigned int loh = 0, doh;
+	int loh = 0, doh;
 
 	IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
 
@@ -92,8 +92,8 @@ ip_vs_nq_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		}
 
 		if (!least ||
-		    (loh * atomic_read(&dest->weight) >
+		    ((__s64)loh * atomic_read(&dest->weight) >
-		     doh * atomic_read(&least->weight))) {
+		     (__s64)doh * atomic_read(&least->weight))) {
 			least = dest;
 			loh = doh;
 		}

net/netfilter/ipvs/ip_vs_sed.c

@@ -44,7 +44,7 @@
 #include <net/ip_vs.h>
 
 
-static inline unsigned int
+static inline int
 ip_vs_sed_dest_overhead(struct ip_vs_dest *dest)
 {
 	/*
@@ -63,7 +63,7 @@ ip_vs_sed_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		   struct ip_vs_iphdr *iph)
 {
 	struct ip_vs_dest *dest, *least;
-	unsigned int loh, doh;
+	int loh, doh;
 
 	IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
 
@@ -99,8 +99,8 @@ ip_vs_sed_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 			continue;
 		doh = ip_vs_sed_dest_overhead(dest);
-		if (loh * atomic_read(&dest->weight) >
+		if ((__s64)loh * atomic_read(&dest->weight) >
-		    doh * atomic_read(&least->weight)) {
+		    (__s64)doh * atomic_read(&least->weight)) {
 			least = dest;
 			loh = doh;
 		}

net/netfilter/ipvs/ip_vs_wlc.c

@@ -35,7 +35,7 @@ ip_vs_wlc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		   struct ip_vs_iphdr *iph)
 {
 	struct ip_vs_dest *dest, *least;
-	unsigned int loh, doh;
+	int loh, doh;
 
 	IP_VS_DBG(6, "ip_vs_wlc_schedule(): Scheduling...\n");
 
@@ -71,8 +71,8 @@ ip_vs_wlc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 			continue;
 		doh = ip_vs_dest_conn_overhead(dest);
-		if (loh * atomic_read(&dest->weight) >
+		if ((__s64)loh * atomic_read(&dest->weight) >
-		    doh * atomic_read(&least->weight)) {
+		    (__s64)doh * atomic_read(&least->weight)) {
 			least = dest;
 			loh = doh;
 		}

net/netfilter/nf_synproxy_core.c

@@ -24,7 +24,7 @@
 int synproxy_net_id;
 EXPORT_SYMBOL_GPL(synproxy_net_id);
 
-void
+bool
 synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
 		       const struct tcphdr *th, struct synproxy_options *opts)
 {
@@ -32,7 +32,8 @@ synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
 	u8 buf[40], *ptr;
 
 	ptr = skb_header_pointer(skb, doff + sizeof(*th), length, buf);
-	BUG_ON(ptr == NULL);
+	if (ptr == NULL)
+		return false;
 
 	opts->options = 0;
 	while (length > 0) {
@@ -41,16 +42,16 @@ synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
 
 		switch (opcode) {
 		case TCPOPT_EOL:
-			return;
+			return true;
 		case TCPOPT_NOP:
 			length--;
 			continue;
 		default:
 			opsize = *ptr++;
 			if (opsize < 2)
-				return;
+				return true;
 			if (opsize > length)
-				return;
+				return true;
 
 			switch (opcode) {
 			case TCPOPT_MSS:
@@ -84,6 +85,7 @@ synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
 			length -= opsize;
 		}
 	}
+	return true;
 }
 EXPORT_SYMBOL_GPL(synproxy_parse_options);