Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

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

1) Missing TCP header sanity check in TCPMSS target, from Eric Dumazet.

2) Incorrect event message type for related conntracks created via
   ctnetlink, from Liping Zhang.

3) Fix incorrect rcu locking when handling helpers from ctnetlink,
   from Gao feng.

4) Fix missing rcu locking when updating helper, from Liping Zhang.

5) Fix missing read_lock_bh when iterating over list of device addresses
   from TPROXY and redirect, also from Liping.

6) Fix crash when trying to dump expectations from conntrack with no
   helper via ctnetlink, from Liping.

7) Missing RCU protection to expecation list update given ctnetlink
   iterates over the list under rcu read lock side, from Liping too.

8) Don't dump autogenerated seed in nft_hash to userspace, this is
   very confusing to the user, again from Liping.

9) Fix wrong conntrack netns module refcount in ipt_CLUSTERIP,
   from Gao feng.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/netfilter/ipt_CLUSTERIP.c

@@ -461,7 +461,7 @@ static void clusterip_tg_destroy(const struct xt_tgdtor_param *par)
 
 	clusterip_config_put(cipinfo->config);
 
-	nf_ct_netns_get(par->net, par->family);
+	nf_ct_netns_put(par->net, par->family);
 }
 
 #ifdef CONFIG_COMPAT

net/netfilter/nf_conntrack_expect.c

@@ -57,7 +57,7 @@ void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
 	hlist_del_rcu(&exp->hnode);
 	net->ct.expect_count--;
 
-	hlist_del(&exp->lnode);
+	hlist_del_rcu(&exp->lnode);
 	master_help->expecting[exp->class]--;
 
 	nf_ct_expect_event_report(IPEXP_DESTROY, exp, portid, report);
@@ -363,7 +363,7 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
 	/* two references : one for hash insert, one for the timer */
 	atomic_add(2, &exp->use);
 
-	hlist_add_head(&exp->lnode, &master_help->expectations);
+	hlist_add_head_rcu(&exp->lnode, &master_help->expectations);
 	master_help->expecting[exp->class]++;
 
 	hlist_add_head_rcu(&exp->hnode, &nf_ct_expect_hash[h]);

net/netfilter/nf_conntrack_helper.c

@@ -158,16 +158,25 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum)
 {
 	struct nf_conntrack_helper *h;
 
+	rcu_read_lock();
+
 	h = __nf_conntrack_helper_find(name, l3num, protonum);
 #ifdef CONFIG_MODULES
 	if (h == NULL) {
-		if (request_module("nfct-helper-%s", name) == 0)
+		rcu_read_unlock();
+		if (request_module("nfct-helper-%s", name) == 0) {
+			rcu_read_lock();
 			h = __nf_conntrack_helper_find(name, l3num, protonum);
+		} else {
+			return h;
+		}
 	}
 #endif
 	if (h != NULL && !try_module_get(h->me))
 		h = NULL;
 
+	rcu_read_unlock();
+
 	return h;
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get);
@@ -311,38 +320,36 @@ void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n)
 }
 EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister);
 
+/* Caller should hold the rcu lock */
 struct nf_ct_helper_expectfn *
 nf_ct_helper_expectfn_find_by_name(const char *name)
 {
 	struct nf_ct_helper_expectfn *cur;
 	bool found = false;
 
-	rcu_read_lock();
 	list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) {
 		if (!strcmp(cur->name, name)) {
 			found = true;
 			break;
 		}
 	}
-	rcu_read_unlock();
 	return found ? cur : NULL;
 }
 EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_name);
 
+/* Caller should hold the rcu lock */
 struct nf_ct_helper_expectfn *
 nf_ct_helper_expectfn_find_by_symbol(const void *symbol)
 {
 	struct nf_ct_helper_expectfn *cur;
 	bool found = false;
 
-	rcu_read_lock();
 	list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) {
 		if (cur->expectfn == symbol) {
 			found = true;
 			break;
 		}
 	}
-	rcu_read_unlock();
 	return found ? cur : NULL;
 }
 EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol);

net/netfilter/nf_conntrack_netlink.c

@@ -1488,11 +1488,16 @@ static int ctnetlink_change_helper(struct nf_conn *ct,
 		 * treat the second attempt as a no-op instead of returning
 		 * an error.
 		 */
-		if (help && help->helper &&
-		    !strcmp(help->helper->name, helpname))
-			return 0;
-		else
-			return -EBUSY;
+		err = -EBUSY;
+		if (help) {
+			rcu_read_lock();
+			helper = rcu_dereference(help->helper);
+			if (helper && !strcmp(helper->name, helpname))
+				err = 0;
+			rcu_read_unlock();
+		}
+
+		return err;
 	}
 
 	if (!strcmp(helpname, "")) {
@@ -1929,9 +1934,9 @@ static int ctnetlink_new_conntrack(struct net *net, struct sock *ctnl,
 
 			err = 0;
 			if (test_bit(IPS_EXPECTED_BIT, &ct->status))
-				events = IPCT_RELATED;
+				events = 1 << IPCT_RELATED;
 			else
-				events = IPCT_NEW;
+				events = 1 << IPCT_NEW;
 
 			if (cda[CTA_LABELS] &&
 			    ctnetlink_attach_labels(ct, cda) == 0)
@@ -2675,8 +2680,8 @@ ctnetlink_exp_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 	last = (struct nf_conntrack_expect *)cb->args[1];
 	for (; cb->args[0] < nf_ct_expect_hsize; cb->args[0]++) {
 restart:
-		hlist_for_each_entry(exp, &nf_ct_expect_hash[cb->args[0]],
-				     hnode) {
+		hlist_for_each_entry_rcu(exp, &nf_ct_expect_hash[cb->args[0]],
+					 hnode) {
 			if (l3proto && exp->tuple.src.l3num != l3proto)
 				continue;
 
@@ -2727,7 +2732,7 @@ ctnetlink_exp_ct_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 	rcu_read_lock();
 	last = (struct nf_conntrack_expect *)cb->args[1];
 restart:
-	hlist_for_each_entry(exp, &help->expectations, lnode) {
+	hlist_for_each_entry_rcu(exp, &help->expectations, lnode) {
 		if (l3proto && exp->tuple.src.l3num != l3proto)
 			continue;
 		if (cb->args[1]) {
@@ -2789,6 +2794,12 @@ static int ctnetlink_dump_exp_ct(struct net *net, struct sock *ctnl,
 		return -ENOENT;
 
 	ct = nf_ct_tuplehash_to_ctrack(h);
+	/* No expectation linked to this connection tracking. */
+	if (!nfct_help(ct)) {
+		nf_ct_put(ct);
+		return 0;
+	}
+
 	c.data = ct;
 
 	err = netlink_dump_start(ctnl, skb, nlh, &c);
@@ -3133,23 +3144,27 @@ ctnetlink_create_expect(struct net *net,
 		return -ENOENT;
 	ct = nf_ct_tuplehash_to_ctrack(h);
 
+	rcu_read_lock();
 	if (cda[CTA_EXPECT_HELP_NAME]) {
 		const char *helpname = nla_data(cda[CTA_EXPECT_HELP_NAME]);
 
 		helper = __nf_conntrack_helper_find(helpname, u3,
 						    nf_ct_protonum(ct));
 		if (helper == NULL) {
+			rcu_read_unlock();
 #ifdef CONFIG_MODULES
 			if (request_module("nfct-helper-%s", helpname) < 0) {
 				err = -EOPNOTSUPP;
 				goto err_ct;
 			}
+			rcu_read_lock();
 			helper = __nf_conntrack_helper_find(helpname, u3,
 							    nf_ct_protonum(ct));
 			if (helper) {
 				err = -EAGAIN;
-				goto err_ct;
+				goto err_rcu;
 			}
+			rcu_read_unlock();
 #endif
 			err = -EOPNOTSUPP;
 			goto err_ct;
@@ -3159,11 +3174,13 @@ ctnetlink_create_expect(struct net *net,
 	exp = ctnetlink_alloc_expect(cda, ct, helper, &tuple, &mask);
 	if (IS_ERR(exp)) {
 		err = PTR_ERR(exp);
-		goto err_ct;
+		goto err_rcu;
 	}
 
 	err = nf_ct_expect_related_report(exp, portid, report);
 	nf_ct_expect_put(exp);
+err_rcu:
+	rcu_read_unlock();
 err_ct:
 	nf_ct_put(ct);
 	return err;

net/netfilter/nf_nat_redirect.c

@@ -101,11 +101,13 @@ nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range *range,
 		rcu_read_lock();
 		idev = __in6_dev_get(skb->dev);
 		if (idev != NULL) {
+			read_lock_bh(&idev->lock);
 			list_for_each_entry(ifa, &idev->addr_list, if_list) {
 				newdst = ifa->addr;
 				addr = true;
 				break;
 			}
+			read_unlock_bh(&idev->lock);
 		}
 		rcu_read_unlock();
 

net/netfilter/nft_hash.c

@@ -21,6 +21,7 @@ struct nft_hash {
 	enum nft_registers      sreg:8;
 	enum nft_registers      dreg:8;
 	u8			len;
+	bool			autogen_seed:1;
 	u32			modulus;
 	u32			seed;
 	u32			offset;
@@ -82,10 +83,12 @@ static int nft_hash_init(const struct nft_ctx *ctx,
 	if (priv->offset + priv->modulus - 1 < priv->offset)
 		return -EOVERFLOW;
 
-	if (tb[NFTA_HASH_SEED])
+	if (tb[NFTA_HASH_SEED]) {
 		priv->seed = ntohl(nla_get_be32(tb[NFTA_HASH_SEED]));
-	else
+	} else {
+		priv->autogen_seed = true;
 		get_random_bytes(&priv->seed, sizeof(priv->seed));
+	}
 
 	return nft_validate_register_load(priv->sreg, len) &&
 	       nft_validate_register_store(ctx, priv->dreg, NULL,
@@ -105,7 +108,8 @@ static int nft_hash_dump(struct sk_buff *skb,
 		goto nla_put_failure;
 	if (nla_put_be32(skb, NFTA_HASH_MODULUS, htonl(priv->modulus)))
 		goto nla_put_failure;
-	if (nla_put_be32(skb, NFTA_HASH_SEED, htonl(priv->seed)))
+	if (!priv->autogen_seed &&
+	    nla_put_be32(skb, NFTA_HASH_SEED, htonl(priv->seed)))
 		goto nla_put_failure;
 	if (priv->offset != 0)
 		if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset)))

net/netfilter/xt_TCPMSS.c

@@ -104,7 +104,7 @@ tcpmss_mangle_packet(struct sk_buff *skb,
 	tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
 	tcp_hdrlen = tcph->doff * 4;
 
-	if (len < tcp_hdrlen)
+	if (len < tcp_hdrlen || tcp_hdrlen < sizeof(struct tcphdr))
 		return -1;
 
 	if (info->mss == XT_TCPMSS_CLAMP_PMTU) {
@@ -152,6 +152,10 @@ tcpmss_mangle_packet(struct sk_buff *skb,
 	if (len > tcp_hdrlen)
 		return 0;
 
+	/* tcph->doff has 4 bits, do not wrap it to 0 */
+	if (tcp_hdrlen >= 15 * 4)
+		return 0;
+
 	/*
 	 * MSS Option not found ?! add it..
 	 */

net/netfilter/xt_TPROXY.c

@@ -393,7 +393,8 @@ tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
 
 	rcu_read_lock();
 	indev = __in6_dev_get(skb->dev);
-	if (indev)
+	if (indev) {
+		read_lock_bh(&indev->lock);
 		list_for_each_entry(ifa, &indev->addr_list, if_list) {
 			if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED))
 				continue;
@@ -401,6 +402,8 @@ tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
 			laddr = &ifa->addr;
 			break;
 		}
+		read_unlock_bh(&indev->lock);
+	}
 	rcu_read_unlock();
 
 	return laddr ? laddr : daddr;