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) Revisit warning logic when not applying default helper assignment.
Jiri Kosina considers we are breaking existing setups and not warning
our users accordinly now that automatic helper assignment has been
turned off by default. So let's make him happy by spotting the warning
by when we find a helper but we cannot attach, instead of warning on the
former deprecated behaviour. Patch from Jiri Kosina.

2) Two patches to fix regression in ctnetlink interfaces with
nfnetlink_queue. Specifically, perform more relaxed in CTA_STATUS
and do not bail out if CTA_HELP indicates the same helper that we
already have. Patches from Kevin Cernekee.

3) A couple of bugfixes for ipset via Jozsef Kadlecsik. Due to wrong
index logic in hash set types and null pointer exception in the
list:set type.

4) hashlimit bails out with correct userspace parameters due to wrong
arithmetics in the code that avoids "divide by zero" when
transforming the userspace timing in milliseconds to token credits.
Patch from Alban Browaeys.

5) Fix incorrect NFQA_VLAN_MAX definition, patch from
Ken-ichirou MATSUZAWA.

6) Don't not declare nfnetlink batch error list as static, since this
may be used by several subsystems at the same time. Patch from
Liping Zhang.
====================

Signed-off-by: David S. Miller <[e-mail]>

include/uapi/linux/netfilter/nf_conntrack_common.h

···
 	IPS_DYING_BIT = 9,
 	IPS_DYING = (1 << IPS_DYING_BIT),
 
+	/* Bits that cannot be altered from userland. */
+	IPS_UNCHANGEABLE_MASK = (IPS_NAT_DONE_MASK | IPS_NAT_MASK |
+				 IPS_EXPECTED | IPS_CONFIRMED | IPS_DYING),
+
 	/* Connection has fixed timeout. */
 	IPS_FIXED_TIMEOUT_BIT = 10,
 	IPS_FIXED_TIMEOUT = (1 << IPS_FIXED_TIMEOUT_BIT),

include/uapi/linux/netfilter/nfnetlink_queue.h

···
 	NFQA_VLAN_TCI,			/* __be16 skb htons(vlan_tci) */
 	__NFQA_VLAN_MAX,
 };
-#define NFQA_VLAN_MAX (__NFQA_VLAN_MAX + 1)
+#define NFQA_VLAN_MAX (__NFQA_VLAN_MAX - 1)
 
 enum nfqnl_attr_type {
 	NFQA_UNSPEC,

net/netfilter/ipset/ip_set_hash_gen.h

···
 					continue;
 				data = ahash_data(n, j, dsize);
 				memcpy(tmp->value + k * dsize, data, dsize);
-				set_bit(j, tmp->used);
+				set_bit(k, tmp->used);
 				k++;
 			}
 			tmp->pos = k;

net/netfilter/ipset/ip_set_list_set.c

···
 		else
 			prev = e;
 	}
+
+	/* If before/after is used on an empty set */
+	if ((d->before > 0 && !next) ||
+	    (d->before < 0 && !prev))
+		return -IPSET_ERR_REF_EXIST;
+
 	/* Re-add already existing element */
 	if (n) {
-		if ((d->before > 0 && !next) ||
-		    (d->before < 0 && !prev))
-			return -IPSET_ERR_REF_EXIST;
 		if (!flag_exist)
 			return -IPSET_ERR_EXIST;
 		/* Update extensions */

net/netfilter/nf_conntrack_helper.c

···
 }
 EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add);
 
+static struct nf_conntrack_helper *
+nf_ct_lookup_helper(struct nf_conn *ct, struct net *net)
+{
+	if (!net->ct.sysctl_auto_assign_helper) {
+		if (net->ct.auto_assign_helper_warned)
+			return NULL;
+		if (!__nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple))
+			return NULL;
+		pr_info("nf_conntrack: default automatic helper assignment "
+			"has been turned off for security reasons and CT-based "
+			" firewall rule not found. Use the iptables CT target "
+			"to attach helpers instead.\n");
+		net->ct.auto_assign_helper_warned = 1;
+		return NULL;
+	}
+
+	return __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+}
+
+
 int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
 			      gfp_t flags)
 {
···
 	}
 
 	help = nfct_help(ct);
-	if (net->ct.sysctl_auto_assign_helper && helper == NULL) {
-		helper = __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
-		if (unlikely(!net->ct.auto_assign_helper_warned && helper)) {
-			pr_info("nf_conntrack: automatic helper "
-				"assignment is deprecated and it will "
-				"be removed soon. Use the iptables CT target "
-				"to attach helpers instead.\n");
-			net->ct.auto_assign_helper_warned = true;
-		}
-	}
 
 	if (helper == NULL) {
-		if (help)
-			RCU_INIT_POINTER(help->helper, NULL);
-		return 0;
+		helper = nf_ct_lookup_helper(ct, net);
+		if (helper == NULL) {
+			if (help)
+				RCU_INIT_POINTER(help->helper, NULL);
+			return 0;
+		}
 	}
 
 	if (help == NULL) {

net/netfilter/nf_conntrack_netlink.c

···
 	struct nlattr *helpinfo = NULL;
 	int err;
 
-	/* don't change helper of sibling connections */
-	if (ct->master)
-		return -EBUSY;
-
 	err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);
 	if (err < 0)
 		return err;
+
+	/* don't change helper of sibling connections */
+	if (ct->master) {
+		/* If we try to change the helper to the same thing twice,
+		 * 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;
+	}
 
 	if (!strcmp(helpname, "")) {
 		if (help && help->helper) {
···
 }
 
 static int
+ctnetlink_update_status(struct nf_conn *ct, const struct nlattr * const cda[])
+{
+	unsigned int status = ntohl(nla_get_be32(cda[CTA_STATUS]));
+	unsigned long d = ct->status ^ status;
+
+	if (d & IPS_SEEN_REPLY && !(status & IPS_SEEN_REPLY))
+		/* SEEN_REPLY bit can only be set */
+		return -EBUSY;
+
+	if (d & IPS_ASSURED && !(status & IPS_ASSURED))
+		/* ASSURED bit can only be set */
+		return -EBUSY;
+
+	/* This check is less strict than ctnetlink_change_status()
+	 * because callers often flip IPS_EXPECTED bits when sending
+	 * an NFQA_CT attribute to the kernel.  So ignore the
+	 * unchangeable bits but do not error out.
+	 */
+	ct->status = (status & ~IPS_UNCHANGEABLE_MASK) |
+		     (ct->status & IPS_UNCHANGEABLE_MASK);
+	return 0;
+}
+
+static int
 ctnetlink_glue_parse_ct(const struct nlattr *cda[], struct nf_conn *ct)
 {
 	int err;
···
 			return err;
 	}
 	if (cda[CTA_STATUS]) {
-		err = ctnetlink_change_status(ct, cda);
+		err = ctnetlink_update_status(ct, cda);
 		if (err < 0)
 			return err;
 	}

net/netfilter/nfnetlink.c

···
 	struct net *net = sock_net(skb->sk);
 	const struct nfnetlink_subsystem *ss;
 	const struct nfnl_callback *nc;
-	static LIST_HEAD(err_list);
+	LIST_HEAD(err_list);
 	u32 status;
 	int err;
 

net/netfilter/xt_hashlimit.c

···
 /* Precision saver. */
 static u64 user2credits(u64 user, int revision)
 {
-	if (revision == 1) {
-		/* If multiplying would overflow... */
-		if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY_v1))
-			/* Divide first. */
-			return div64_u64(user, XT_HASHLIMIT_SCALE)
-				* HZ * CREDITS_PER_JIFFY_v1;
+	u64 scale = (revision == 1) ?
+		XT_HASHLIMIT_SCALE : XT_HASHLIMIT_SCALE_v2;
+	u64 cpj = (revision == 1) ?
+		CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY;
 
-		return div64_u64(user * HZ * CREDITS_PER_JIFFY_v1,
-				 XT_HASHLIMIT_SCALE);
-	} else {
-		if (user > 0xFFFFFFFFFFFFFFFFULL / (HZ*CREDITS_PER_JIFFY))
-			return div64_u64(user, XT_HASHLIMIT_SCALE_v2)
-				* HZ * CREDITS_PER_JIFFY;
+	/* Avoid overflow: divide the constant operands first */
+	if (scale >= HZ * cpj)
+		return div64_u64(user, div64_u64(scale, HZ * cpj));
 
-		return div64_u64(user * HZ * CREDITS_PER_JIFFY,
-				 XT_HASHLIMIT_SCALE_v2);
-	}
+	return user * div64_u64(HZ * cpj, scale);
 }
 
 static u32 user2credits_byte(u32 user)