[PATCH 0/7] Netfilter updates for net-next

[PATCH 0/7] Netfilter updates for net-next

[Pablo Neira Ayuso]

Hi,

1) UAF in chain binding support from previous batch, from Dan Carpenter.

2) Queue up delayed work to expire connections with no destination,
   from Andrew Sy Kim.

3) Use fallthrough pseudo-keyword, from Gustavo A. R. Silva.

4) Replace HTTP links with HTTPS, from Alexander A. Klimov.

5) Remove superfluous null header checks in ip6tables, from
   Gaurav Singh.

6) Add extended netlink error reporting for expression.

7) Report EEXIST on overlapping chain, set elements and flowtable
   devices.

Please, pull these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git

Thank you.

----------------------------------------------------------------

The following changes since commit 4ff91fa0a3acd072c9a46ebe08a6e2471ddd3c95:

  Merge branch 'udp_tunnel-NIC-RX-port-offload-infrastructure' (2020-07-14 17:04:28 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git HEAD

for you to fetch changes up to 77a92189ecfd061616ad531d386639aab7baaad9:

  netfilter: nf_tables: report EEXIST on overlaps (2020-08-02 19:53:45 +0200)

----------------------------------------------------------------
Alexander A. Klimov (1):
      netfilter: Replace HTTP links with HTTPS ones

Andrew Sy Kim (1):
      ipvs: queue delayed work to expire no destination connections if expire_nodest_conn=1

Dan Carpenter (1):
      netfilter: nf_tables: Fix a use after free in nft_immediate_destroy()

Gaurav Singh (1):
      netfilter: ip6tables: Remove redundant null checks

Gustavo A. R. Silva (1):
      netfilter: Use fallthrough pseudo-keyword

Pablo Neira Ayuso (2):
      netfilter: nf_tables: extended netlink error reporting for expressions
      netfilter: nf_tables: report EEXIST on overlaps

 include/net/ip_vs.h                        | 29 ++++++++++++++++++
 include/uapi/linux/netfilter/xt_connmark.h |  2 +-
 net/bridge/netfilter/ebtables.c            |  2 +-
 net/decnet/netfilter/dn_rtmsg.c            |  2 +-
 net/ipv6/netfilter/ip6t_ah.c               |  3 +-
 net/ipv6/netfilter/ip6t_frag.c             |  3 +-
 net/ipv6/netfilter/ip6t_hbh.c              |  3 +-
 net/ipv6/netfilter/ip6t_rt.c               |  3 +-
 net/netfilter/Kconfig                      |  2 +-
 net/netfilter/ipset/ip_set_core.c          |  2 +-
 net/netfilter/ipvs/ip_vs_conn.c            | 39 +++++++++++++++++++++++++
 net/netfilter/ipvs/ip_vs_core.c            | 47 +++++++++++++-----------------
 net/netfilter/ipvs/ip_vs_ctl.c             | 22 ++++++++++++++
 net/netfilter/nf_conntrack_h323_asn1.c     |  6 ++--
 net/netfilter/nf_conntrack_proto.c         |  2 +-
 net/netfilter/nf_conntrack_proto_tcp.c     |  2 +-
 net/netfilter/nf_conntrack_standalone.c    |  2 +-
 net/netfilter/nf_nat_core.c                | 12 ++++----
 net/netfilter/nf_synproxy_core.c           |  6 ++--
 net/netfilter/nf_tables_api.c              | 31 +++++++++++---------
 net/netfilter/nf_tables_core.c             |  2 +-
 net/netfilter/nfnetlink_acct.c             |  2 +-
 net/netfilter/nfnetlink_cttimeout.c        |  2 +-
 net/netfilter/nft_cmp.c                    |  4 +--
 net/netfilter/nft_ct.c                     |  6 ++--
 net/netfilter/nft_fib.c                    |  2 +-
 net/netfilter/nft_immediate.c              |  4 +--
 net/netfilter/nft_payload.c                |  2 +-
 net/netfilter/nft_set_pipapo.c             |  4 +--
 net/netfilter/utils.c                      |  8 ++---
 net/netfilter/x_tables.c                   |  2 +-
 net/netfilter/xt_CONNSECMARK.c             |  2 +-
 net/netfilter/xt_connmark.c                |  2 +-
 net/netfilter/xt_nfacct.c                  |  2 +-
 net/netfilter/xt_time.c                    |  2 +-
 35 files changed, 173 insertions(+), 93 deletions(-)

[PATCH 1/7] netfilter: nf_tables: Fix a use after free in nft_immediate_destroy()

[Pablo Neira Ayuso]

From: Dan Carpenter <dan.carpenter@oracle.com>

The nf_tables_rule_release() function frees "rule" so we have to use
the _safe() version of list_for_each_entry().

Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_immediate.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c
index 9e556638bb32..c63eb3b17178 100644
--- a/net/netfilter/nft_immediate.c
+++ b/net/netfilter/nft_immediate.c
@@ -103,9 +103,9 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx,
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 	const struct nft_data *data = &priv->data;
+	struct nft_rule *rule, *n;
 	struct nft_ctx chain_ctx;
 	struct nft_chain *chain;
-	struct nft_rule *rule;
 
 	if (priv->dreg != NFT_REG_VERDICT)
 		return;
@@ -121,7 +121,7 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx,
 		chain_ctx = *ctx;
 		chain_ctx.chain = chain;
 
-		list_for_each_entry(rule, &chain->rules, list)
+		list_for_each_entry_safe(rule, n, &chain->rules, list)
 			nf_tables_rule_release(&chain_ctx, rule);
 
 		nf_tables_chain_destroy(&chain_ctx);
-- 
2.20.1

[PATCH 2/7] ipvs: queue delayed work to expire no destination connections if expire_nodest_conn=1

[Pablo Neira Ayuso]

From: Andrew Sy Kim <kim.andrewsy@gmail.com>

When expire_nodest_conn=1 and a destination is deleted, IPVS does not
expire the existing connections until the next matching incoming packet.
If there are many connection entries from a single client to a single
destination, many packets may get dropped before all the connections are
expired (more likely with lots of UDP traffic). An optimization can be
made where upon deletion of a destination, IPVS queues up delayed work
to immediately expire any connections with a deleted destination. This
ensures any reused source ports from a client (within the IPVS timeouts)
are scheduled to new real servers instead of silently dropped.

Signed-off-by: Andrew Sy Kim <kim.andrewsy@gmail.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/ip_vs.h             | 29 ++++++++++++++++++++
 net/netfilter/ipvs/ip_vs_conn.c | 39 +++++++++++++++++++++++++++
 net/netfilter/ipvs/ip_vs_core.c | 47 ++++++++++++++-------------------
 net/netfilter/ipvs/ip_vs_ctl.c  | 22 +++++++++++++++
 4 files changed, 110 insertions(+), 27 deletions(-)

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 011f407b76fe..9a59a33787cb 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -14,6 +14,7 @@
 #include <linux/spinlock.h>             /* for struct rwlock_t */
 #include <linux/atomic.h>               /* for struct atomic_t */
 #include <linux/refcount.h>             /* for struct refcount_t */
+#include <linux/workqueue.h>
 
 #include <linux/compiler.h>
 #include <linux/timer.h>
@@ -886,6 +887,8 @@ struct netns_ipvs {
 	atomic_t		conn_out_counter;
 
 #ifdef CONFIG_SYSCTL
+	/* delayed work for expiring no dest connections */
+	struct delayed_work	expire_nodest_conn_work;
 	/* 1/rate drop and drop-entry variables */
 	struct delayed_work	defense_work;   /* Work handler */
 	int			drop_rate;
@@ -1051,6 +1054,11 @@ static inline int sysctl_conn_reuse_mode(struct netns_ipvs *ipvs)
 	return ipvs->sysctl_conn_reuse_mode;
 }
 
+static inline int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
+{
+	return ipvs->sysctl_expire_nodest_conn;
+}
+
 static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs)
 {
 	return ipvs->sysctl_schedule_icmp;
@@ -1138,6 +1146,11 @@ static inline int sysctl_conn_reuse_mode(struct netns_ipvs *ipvs)
 	return 1;
 }
 
+static inline int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
+{
+	return 0;
+}
+
 static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs)
 {
 	return 0;
@@ -1507,6 +1520,22 @@ static inline int ip_vs_todrop(struct netns_ipvs *ipvs)
 static inline int ip_vs_todrop(struct netns_ipvs *ipvs) { return 0; }
 #endif
 
+#ifdef CONFIG_SYSCTL
+/* Enqueue delayed work for expiring no dest connections
+ * Only run when sysctl_expire_nodest=1
+ */
+static inline void ip_vs_enqueue_expire_nodest_conns(struct netns_ipvs *ipvs)
+{
+	if (sysctl_expire_nodest_conn(ipvs))
+		queue_delayed_work(system_long_wq,
+				   &ipvs->expire_nodest_conn_work, 1);
+}
+
+void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs);
+#else
+static inline void ip_vs_enqueue_expire_nodest_conns(struct netns_ipvs *ipvs) {}
+#endif
+
 #define IP_VS_DFWD_METHOD(dest) (atomic_read(&(dest)->conn_flags) & \
 				 IP_VS_CONN_F_FWD_MASK)
 
diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index b3921ae92740..a90b8eac16ac 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -1389,6 +1389,45 @@ static void ip_vs_conn_flush(struct netns_ipvs *ipvs)
 		goto flush_again;
 	}
 }
+
+#ifdef CONFIG_SYSCTL
+void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs)
+{
+	int idx;
+	struct ip_vs_conn *cp, *cp_c;
+	struct ip_vs_dest *dest;
+
+	rcu_read_lock();
+	for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
+		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
+			if (cp->ipvs != ipvs)
+				continue;
+
+			dest = cp->dest;
+			if (!dest || (dest->flags & IP_VS_DEST_F_AVAILABLE))
+				continue;
+
+			if (atomic_read(&cp->n_control))
+				continue;
+
+			cp_c = cp->control;
+			IP_VS_DBG(4, "del connection\n");
+			ip_vs_conn_del(cp);
+			if (cp_c && !atomic_read(&cp_c->n_control)) {
+				IP_VS_DBG(4, "del controlling connection\n");
+				ip_vs_conn_del(cp_c);
+			}
+		}
+		cond_resched_rcu();
+
+		/* netns clean up started, abort delayed work */
+		if (!ipvs->enable)
+			break;
+	}
+	rcu_read_unlock();
+}
+#endif
+
 /*
  * per netns init and exit
  */
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index b4a6b7662f3f..e3668a6e54e4 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -694,16 +694,10 @@ static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs)
 	return ipvs->sysctl_nat_icmp_send;
 }
 
-static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
-{
-	return ipvs->sysctl_expire_nodest_conn;
-}
-
 #else
 
 static int sysctl_snat_reroute(struct netns_ipvs *ipvs) { return 0; }
 static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs) { return 0; }
-static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; }
 
 #endif
 
@@ -2097,36 +2091,35 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
 		}
 	}
 
-	if (unlikely(!cp)) {
-		int v;
-
-		if (!ip_vs_try_to_schedule(ipvs, af, skb, pd, &v, &cp, &iph))
-			return v;
-	}
-
-	IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet");
-
 	/* Check the server status */
-	if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
+	if (cp && cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
 		/* the destination server is not available */
+		if (sysctl_expire_nodest_conn(ipvs)) {
+			bool old_ct = ip_vs_conn_uses_old_conntrack(cp, skb);
 
-		__u32 flags = cp->flags;
-
-		/* when timer already started, silently drop the packet.*/
-		if (timer_pending(&cp->timer))
-			__ip_vs_conn_put(cp);
-		else
-			ip_vs_conn_put(cp);
+			if (!old_ct)
+				cp->flags &= ~IP_VS_CONN_F_NFCT;
 
-		if (sysctl_expire_nodest_conn(ipvs) &&
-		    !(flags & IP_VS_CONN_F_ONE_PACKET)) {
-			/* try to expire the connection immediately */
 			ip_vs_conn_expire_now(cp);
+			__ip_vs_conn_put(cp);
+			if (old_ct)
+				return NF_DROP;
+			cp = NULL;
+		} else {
+			__ip_vs_conn_put(cp);
+			return NF_DROP;
 		}
+	}
 
-		return NF_DROP;
+	if (unlikely(!cp)) {
+		int v;
+
+		if (!ip_vs_try_to_schedule(ipvs, af, skb, pd, &v, &cp, &iph))
+			return v;
 	}
 
+	IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet");
+
 	ip_vs_in_stats(cp, skb);
 	ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
 	if (cp->packet_xmit)
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 4af83f466dfc..f984d2c881ff 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -210,6 +210,17 @@ static void update_defense_level(struct netns_ipvs *ipvs)
 	local_bh_enable();
 }
 
+/* Handler for delayed work for expiring no
+ * destination connections
+ */
+static void expire_nodest_conn_handler(struct work_struct *work)
+{
+	struct netns_ipvs *ipvs;
+
+	ipvs = container_of(work, struct netns_ipvs,
+			    expire_nodest_conn_work.work);
+	ip_vs_expire_nodest_conn_flush(ipvs);
+}
 
 /*
  *	Timer for checking the defense
@@ -1164,6 +1175,12 @@ static void __ip_vs_del_dest(struct netns_ipvs *ipvs, struct ip_vs_dest *dest,
 	list_add(&dest->t_list, &ipvs->dest_trash);
 	dest->idle_start = 0;
 	spin_unlock_bh(&ipvs->dest_trash_lock);
+
+	/* Queue up delayed work to expire all no destination connections.
+	 * No-op when CONFIG_SYSCTL is disabled.
+	 */
+	if (!cleanup)
+		ip_vs_enqueue_expire_nodest_conns(ipvs);
 }
 
 
@@ -4086,6 +4103,10 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
 	queue_delayed_work(system_long_wq, &ipvs->defense_work,
 			   DEFENSE_TIMER_PERIOD);
 
+	/* Init delayed work for expiring no dest conn */
+	INIT_DELAYED_WORK(&ipvs->expire_nodest_conn_work,
+			  expire_nodest_conn_handler);
+
 	return 0;
 }
 
@@ -4093,6 +4114,7 @@ static void __net_exit ip_vs_control_net_cleanup_sysctl(struct netns_ipvs *ipvs)
 {
 	struct net *net = ipvs->net;
 
+	cancel_delayed_work_sync(&ipvs->expire_nodest_conn_work);
 	cancel_delayed_work_sync(&ipvs->defense_work);
 	cancel_work_sync(&ipvs->defense_work.work);
 	unregister_net_sysctl_table(ipvs->sysctl_hdr);
-- 
2.20.1

[PATCH 3/7] netfilter: Use fallthrough pseudo-keyword

[Pablo Neira Ayuso]

From: "Gustavo A. R. Silva" <gustavoars@kernel.org>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/bridge/netfilter/ebtables.c         |  2 +-
 net/netfilter/ipset/ip_set_core.c       |  2 +-
 net/netfilter/nf_conntrack_h323_asn1.c  |  6 +++---
 net/netfilter/nf_conntrack_proto.c      |  2 +-
 net/netfilter/nf_conntrack_proto_tcp.c  |  2 +-
 net/netfilter/nf_conntrack_standalone.c |  2 +-
 net/netfilter/nf_nat_core.c             | 12 ++++++------
 net/netfilter/nf_synproxy_core.c        |  6 ++----
 net/netfilter/nf_tables_api.c           |  8 ++++----
 net/netfilter/nf_tables_core.c          |  2 +-
 net/netfilter/nfnetlink_cttimeout.c     |  2 +-
 net/netfilter/nft_cmp.c                 |  4 ++--
 net/netfilter/nft_ct.c                  |  6 +++---
 net/netfilter/nft_fib.c                 |  2 +-
 net/netfilter/nft_payload.c             |  2 +-
 net/netfilter/utils.c                   |  8 ++++----
 net/netfilter/x_tables.c                |  2 +-
 17 files changed, 34 insertions(+), 36 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index c83ffe912163..38e946fdd041 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1935,7 +1935,7 @@ static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
 			size_kern = match_size;
 		module_put(match->me);
 		break;
-	case EBT_COMPAT_WATCHER: /* fallthrough */
+	case EBT_COMPAT_WATCHER:
 	case EBT_COMPAT_TARGET:
 		wt = xt_request_find_target(NFPROTO_BRIDGE, name,
 					    mwt->u.revision);
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 56621d6bfd29..920b7c4331f0 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1644,7 +1644,7 @@ ip_set_dump_do(struct sk_buff *skb, struct netlink_callback *cb)
 				goto next_set;
 			if (set->variant->uref)
 				set->variant->uref(set, cb, true);
-			/* fall through */
+			fallthrough;
 		default:
 			ret = set->variant->list(set, skb, cb);
 			if (!cb->args[IPSET_CB_ARG0])
diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c
index 573cb4481481..e697a824b001 100644
--- a/net/netfilter/nf_conntrack_h323_asn1.c
+++ b/net/netfilter/nf_conntrack_h323_asn1.c
@@ -257,15 +257,15 @@ static unsigned int get_uint(struct bitstr *bs, int b)
 	case 4:
 		v |= *bs->cur++;
 		v <<= 8;
-		/* fall through */
+		fallthrough;
 	case 3:
 		v |= *bs->cur++;
 		v <<= 8;
-		/* fall through */
+		fallthrough;
 	case 2:
 		v |= *bs->cur++;
 		v <<= 8;
-		/* fall through */
+		fallthrough;
 	case 1:
 		v |= *bs->cur++;
 		break;
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
index a0560d175a7f..95f79980348c 100644
--- a/net/netfilter/nf_conntrack_proto.c
+++ b/net/netfilter/nf_conntrack_proto.c
@@ -610,7 +610,7 @@ void nf_ct_netns_put(struct net *net, uint8_t nfproto)
 	switch (nfproto) {
 	case NFPROTO_BRIDGE:
 		nf_ct_netns_do_put(net, NFPROTO_BRIDGE);
-		/* fall through */
+		fallthrough;
 	case NFPROTO_INET:
 		nf_ct_netns_do_put(net, NFPROTO_IPV4);
 		nf_ct_netns_do_put(net, NFPROTO_IPV6);
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 1926fd56df56..6892e497781c 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -900,7 +900,7 @@ int nf_conntrack_tcp_packet(struct nf_conn *ct,
 				return -NF_REPEAT;
 			return NF_DROP;
 		}
-		/* Fall through */
+		fallthrough;
 	case TCP_CONNTRACK_IGNORE:
 		/* Ignored packets:
 		 *
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 6a26299cb064..a604f43e3e6b 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -60,7 +60,7 @@ print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
 			   ntohs(tuple->src.u.tcp.port),
 			   ntohs(tuple->dst.u.tcp.port));
 		break;
-	case IPPROTO_UDPLITE: /* fallthrough */
+	case IPPROTO_UDPLITE:
 	case IPPROTO_UDP:
 		seq_printf(s, "sport=%hu dport=%hu ",
 			   ntohs(tuple->src.u.udp.port),
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index bfc555fcbc72..ea923f8cf9c4 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -408,7 +408,7 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
 	static const unsigned int max_attempts = 128;
 
 	switch (tuple->dst.protonum) {
-	case IPPROTO_ICMP: /* fallthrough */
+	case IPPROTO_ICMP:
 	case IPPROTO_ICMPV6:
 		/* id is same for either direction... */
 		keyptr = &tuple->src.u.icmp.id;
@@ -442,11 +442,11 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
 		}
 		goto find_free_id;
 #endif
-	case IPPROTO_UDP:	/* fallthrough */
-	case IPPROTO_UDPLITE:	/* fallthrough */
-	case IPPROTO_TCP:	/* fallthrough */
-	case IPPROTO_SCTP:	/* fallthrough */
-	case IPPROTO_DCCP:	/* fallthrough */
+	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE:
+	case IPPROTO_TCP:
+	case IPPROTO_SCTP:
+	case IPPROTO_DCCP:
 		if (maniptype == NF_NAT_MANIP_SRC)
 			keyptr = &tuple->src.u.all;
 		else
diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c
index ebcdc8e54476..9cca35d22927 100644
--- a/net/netfilter/nf_synproxy_core.c
+++ b/net/netfilter/nf_synproxy_core.c
@@ -704,8 +704,7 @@ ipv4_synproxy_hook(void *priv, struct sk_buff *skb,
 		nf_ct_seqadj_init(ct, ctinfo, 0);
 		synproxy->tsoff = 0;
 		this_cpu_inc(snet->stats->conn_reopened);
-
-		/* fall through */
+		fallthrough;
 	case TCP_CONNTRACK_SYN_SENT:
 		if (!synproxy_parse_options(skb, thoff, th, &opts))
 			return NF_DROP;
@@ -1128,8 +1127,7 @@ ipv6_synproxy_hook(void *priv, struct sk_buff *skb,
 		nf_ct_seqadj_init(ct, ctinfo, 0);
 		synproxy->tsoff = 0;
 		this_cpu_inc(snet->stats->conn_reopened);
-
-		/* fall through */
+		fallthrough;
 	case TCP_CONNTRACK_SYN_SENT:
 		if (!synproxy_parse_options(skb, thoff, th, &opts))
 			return NF_DROP;
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 6708a4f2eec8..0d96e4eb754d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4375,7 +4375,7 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
 	case NFT_TRANS_ABORT:
 	case NFT_TRANS_RELEASE:
 		set->use--;
-		/* fall through */
+		fallthrough;
 	default:
 		nf_tables_unbind_set(ctx, set, binding,
 				     phase == NFT_TRANS_COMMIT);
@@ -6256,7 +6256,7 @@ void nf_tables_deactivate_flowtable(const struct nft_ctx *ctx,
 	case NFT_TRANS_ABORT:
 	case NFT_TRANS_RELEASE:
 		flowtable->use--;
-		/* fall through */
+		fallthrough;
 	default:
 		return;
 	}
@@ -7262,7 +7262,7 @@ static int nf_tables_validate(struct net *net)
 		break;
 	case NFT_VALIDATE_NEED:
 		nft_validate_state_update(net, NFT_VALIDATE_DO);
-		/* fall through */
+		fallthrough;
 	case NFT_VALIDATE_DO:
 		list_for_each_entry(table, &net->nft.tables, list) {
 			if (nft_table_validate(net, table) < 0)
@@ -8336,7 +8336,7 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data,
 		default:
 			return -EINVAL;
 		}
-		/* fall through */
+		fallthrough;
 	case NFT_CONTINUE:
 	case NFT_BREAK:
 	case NFT_RETURN:
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index 96c74c4c7176..587897a2498b 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -213,7 +213,7 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv)
 		jumpstack[stackptr].chain = chain;
 		jumpstack[stackptr].rules = rules + 1;
 		stackptr++;
-		/* fall through */
+		fallthrough;
 	case NFT_GOTO:
 		nft_trace_packet(&info, chain, rule,
 				 NFT_TRACETYPE_RULE);
diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c
index da915c224a82..89a381f7f945 100644
--- a/net/netfilter/nfnetlink_cttimeout.c
+++ b/net/netfilter/nfnetlink_cttimeout.c
@@ -451,7 +451,7 @@ static int cttimeout_default_get(struct net *net, struct sock *ctnl,
 	case IPPROTO_TCP:
 		timeouts = nf_tcp_pernet(net)->timeouts;
 		break;
-	case IPPROTO_UDP: /* fallthrough */
+	case IPPROTO_UDP:
 	case IPPROTO_UDPLITE:
 		timeouts = nf_udp_pernet(net)->timeouts;
 		break;
diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c
index 8a28c127effc..16f4d84599ac 100644
--- a/net/netfilter/nft_cmp.c
+++ b/net/netfilter/nft_cmp.c
@@ -43,7 +43,7 @@ void nft_cmp_eval(const struct nft_expr *expr,
 	case NFT_CMP_LT:
 		if (d == 0)
 			goto mismatch;
-		/* fall through */
+		fallthrough;
 	case NFT_CMP_LTE:
 		if (d > 0)
 			goto mismatch;
@@ -51,7 +51,7 @@ void nft_cmp_eval(const struct nft_expr *expr,
 	case NFT_CMP_GT:
 		if (d == 0)
 			goto mismatch;
-		/* fall through */
+		fallthrough;
 	case NFT_CMP_GTE:
 		if (d < 0)
 			goto mismatch;
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 77258af1fce0..322bd674963e 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -129,7 +129,7 @@ static void nft_ct_get_eval(const struct nft_expr *expr,
 		return;
 	}
 #endif
-	case NFT_CT_BYTES: /* fallthrough */
+	case NFT_CT_BYTES:
 	case NFT_CT_PKTS: {
 		const struct nf_conn_acct *acct = nf_conn_acct_find(ct);
 		u64 count = 0;
@@ -1013,8 +1013,8 @@ static int nft_ct_helper_obj_init(const struct nft_ctx *ctx,
 		help6 = nf_conntrack_helper_try_module_get(name, family,
 							   priv->l4proto);
 		break;
-	case NFPROTO_NETDEV: /* fallthrough */
-	case NFPROTO_BRIDGE: /* same */
+	case NFPROTO_NETDEV:
+	case NFPROTO_BRIDGE:
 	case NFPROTO_INET:
 		help4 = nf_conntrack_helper_try_module_get(name, NFPROTO_IPV4,
 							   priv->l4proto);
diff --git a/net/netfilter/nft_fib.c b/net/netfilter/nft_fib.c
index cfac0964f48d..4dfdaeaf09a5 100644
--- a/net/netfilter/nft_fib.c
+++ b/net/netfilter/nft_fib.c
@@ -32,7 +32,7 @@ int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
 	unsigned int hooks;
 
 	switch (priv->result) {
-	case NFT_FIB_RESULT_OIF: /* fallthrough */
+	case NFT_FIB_RESULT_OIF:
 	case NFT_FIB_RESULT_OIFNAME:
 		hooks = (1 << NF_INET_PRE_ROUTING);
 		break;
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index a7de3a58f553..ed7cb9f747f6 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -467,7 +467,7 @@ static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt,
 	case IPPROTO_UDP:
 		if (!nft_payload_udp_checksum(skb, pkt->xt.thoff))
 			return -1;
-		/* Fall through. */
+		fallthrough;
 	case IPPROTO_UDPLITE:
 		*l4csum_offset = offsetof(struct udphdr, check);
 		break;
diff --git a/net/netfilter/utils.c b/net/netfilter/utils.c
index 51b454d8fa9c..cedf47ab3c6f 100644
--- a/net/netfilter/utils.c
+++ b/net/netfilter/utils.c
@@ -25,7 +25,7 @@ __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	case CHECKSUM_NONE:
 		if (protocol != IPPROTO_TCP && protocol != IPPROTO_UDP)
 			skb->csum = 0;
@@ -51,7 +51,7 @@ static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
 	case CHECKSUM_COMPLETE:
 		if (len == skb->len - dataoff)
 			return nf_ip_checksum(skb, hook, dataoff, protocol);
-		/* fall through */
+		fallthrough;
 	case CHECKSUM_NONE:
 		skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,
 					       skb->len - dataoff, 0);
@@ -79,7 +79,7 @@ __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	case CHECKSUM_NONE:
 		skb->csum = ~csum_unfold(
 				csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
@@ -106,7 +106,7 @@ static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
 	case CHECKSUM_COMPLETE:
 		if (len == skb->len - dataoff)
 			return nf_ip6_checksum(skb, hook, dataoff, protocol);
-		/* fall through */
+		fallthrough;
 	case CHECKSUM_NONE:
 		hsum = skb_checksum(skb, 0, dataoff, 0);
 		skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 99a468be4a59..8b2daccaf8df 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1571,7 +1571,7 @@ static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
 		trav->curr = trav->curr->next;
 		if (trav->curr != trav->head)
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		return NULL;
 	}
-- 
2.20.1

[PATCH 4/7] netfilter: Replace HTTP links with HTTPS ones

[Pablo Neira Ayuso]

From: "Alexander A. Klimov" <grandmaster@al2klimov.de>

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/uapi/linux/netfilter/xt_connmark.h | 2 +-
 net/decnet/netfilter/dn_rtmsg.c            | 2 +-
 net/netfilter/Kconfig                      | 2 +-
 net/netfilter/nfnetlink_acct.c             | 2 +-
 net/netfilter/nft_set_pipapo.c             | 4 ++--
 net/netfilter/xt_CONNSECMARK.c             | 2 +-
 net/netfilter/xt_connmark.c                | 2 +-
 net/netfilter/xt_nfacct.c                  | 2 +-
 net/netfilter/xt_time.c                    | 2 +-
 9 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/uapi/linux/netfilter/xt_connmark.h b/include/uapi/linux/netfilter/xt_connmark.h
index 1aa5c955ee1e..f01c19b83a2b 100644
--- a/include/uapi/linux/netfilter/xt_connmark.h
+++ b/include/uapi/linux/netfilter/xt_connmark.h
@@ -4,7 +4,7 @@
 
 #include <linux/types.h>
 
-/* Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
+/* Copyright (C) 2002,2004 MARA Systems AB <https://www.marasystems.com>
  * by Henrik Nordstrom <hno@marasystems.com>
  *
  * This program is free software; you can redistribute it and/or modify
diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index dc705769acc9..26a9193df783 100644
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -6,7 +6,7 @@
  *
  *              DECnet Routing Message Grabulator
  *
- *              (C) 2000 ChyGwyn Limited  -  http://www.chygwyn.com/
+ *              (C) 2000 ChyGwyn Limited  -  https://www.chygwyn.com/
  *
  * Author:      Steven Whitehouse <steve@chygwyn.com>
  */
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 0ffe2b8723c4..25313c29d799 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -447,7 +447,7 @@ config NF_TABLES
 	  replace the existing {ip,ip6,arp,eb}_tables infrastructure. It
 	  provides a pseudo-state machine with an extensible instruction-set
 	  (also known as expressions) that the userspace 'nft' utility
-	  (http://www.netfilter.org/projects/nftables) uses to build the
+	  (https://www.netfilter.org/projects/nftables) uses to build the
 	  rule-set. It also comes with the generic set infrastructure that
 	  allows you to construct mappings between matchings and actions
 	  for performance lookups.
diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c
index 5827117f2635..5bfec829c12f 100644
--- a/net/netfilter/nfnetlink_acct.c
+++ b/net/netfilter/nfnetlink_acct.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
- * (C) 2011 Intra2net AG <http://www.intra2net.com>
+ * (C) 2011 Intra2net AG <https://www.intra2net.com>
  */
 #include <linux/init.h>
 #include <linux/module.h>
diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index cc6082a5f7ad..9944523f5c2c 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -312,7 +312,7 @@
  *      Jay Ligatti, Josh Kuhn, and Chris Gage.
  *      Proceedings of the IEEE International Conference on Computer
  *      Communication Networks (ICCCN), August 2010.
- *      http://www.cse.usf.edu/~ligatti/papers/grouper-conf.pdf
+ *      https://www.cse.usf.edu/~ligatti/papers/grouper-conf.pdf
  *
  * [Rottenstreich 2010]
  *      Worst-Case TCAM Rule Expansion
@@ -325,7 +325,7 @@
  *      Kirill Kogan, Sergey Nikolenko, Ori Rottenstreich, William Culhane,
  *      and Patrick Eugster.
  *      Proceedings of the 2014 ACM conference on SIGCOMM, August 2014.
- *      http://www.sigcomm.org/sites/default/files/ccr/papers/2014/August/2619239-2626294.pdf
+ *      https://www.sigcomm.org/sites/default/files/ccr/papers/2014/August/2619239-2626294.pdf
  */
 
 #include <linux/kernel.h>
diff --git a/net/netfilter/xt_CONNSECMARK.c b/net/netfilter/xt_CONNSECMARK.c
index a5c8b653476a..76acecf3e757 100644
--- a/net/netfilter/xt_CONNSECMARK.c
+++ b/net/netfilter/xt_CONNSECMARK.c
@@ -6,7 +6,7 @@
  * with the SECMARK target and state match.
  *
  * Based somewhat on CONNMARK:
- *   Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
+ *   Copyright (C) 2002,2004 MARA Systems AB <https://www.marasystems.com>
  *    by Henrik Nordstrom <hno@marasystems.com>
  *
  * (C) 2006,2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index eec2f3a88d73..e5ebc0810675 100644
--- a/net/netfilter/xt_connmark.c
+++ b/net/netfilter/xt_connmark.c
@@ -2,7 +2,7 @@
 /*
  *	xt_connmark - Netfilter module to operate on connection marks
  *
- *	Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
+ *	Copyright (C) 2002,2004 MARA Systems AB <https://www.marasystems.com>
  *	by Henrik Nordstrom <hno@marasystems.com>
  *	Copyright © CC Computer Consultants GmbH, 2007 - 2008
  *	Jan Engelhardt <jengelh@medozas.de>
diff --git a/net/netfilter/xt_nfacct.c b/net/netfilter/xt_nfacct.c
index 5aab6df74e0f..a97c2259bbc8 100644
--- a/net/netfilter/xt_nfacct.c
+++ b/net/netfilter/xt_nfacct.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
- * (C) 2011 Intra2net AG <http://www.intra2net.com>
+ * (C) 2011 Intra2net AG <https://www.intra2net.com>
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
diff --git a/net/netfilter/xt_time.c b/net/netfilter/xt_time.c
index 67cb98489415..6aa12d0f54e2 100644
--- a/net/netfilter/xt_time.c
+++ b/net/netfilter/xt_time.c
@@ -5,7 +5,7 @@
  *	based on ipt_time by Fabrice MARIE <fabrice@netfilter.org>
  *	This is a module which is used for time matching
  *	It is using some modified code from dietlibc (localtime() function)
- *	that you can find at http://www.fefe.de/dietlibc/
+ *	that you can find at https://www.fefe.de/dietlibc/
  *	This file is distributed under the terms of the GNU General Public
  *	License (GPL). Copies of the GPL can be obtained from gnu.org/gpl.
  */
-- 
2.20.1

[PATCH 5/7] netfilter: ip6tables: Remove redundant null checks

[Pablo Neira Ayuso]

From: Gaurav Singh <gaurav1086@gmail.com>

Remove superfluous check for NULL pointer to header.

Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv6/netfilter/ip6t_ah.c   | 3 +--
 net/ipv6/netfilter/ip6t_frag.c | 3 +--
 net/ipv6/netfilter/ip6t_hbh.c  | 3 +--
 net/ipv6/netfilter/ip6t_rt.c   | 3 +--
 4 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/net/ipv6/netfilter/ip6t_ah.c b/net/ipv6/netfilter/ip6t_ah.c
index 4e15a14435e4..70da2f2ce064 100644
--- a/net/ipv6/netfilter/ip6t_ah.c
+++ b/net/ipv6/netfilter/ip6t_ah.c
@@ -74,8 +74,7 @@ static bool ah_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		 ahinfo->hdrres, ah->reserved,
 		 !(ahinfo->hdrres && ah->reserved));
 
-	return (ah != NULL) &&
-		spi_match(ahinfo->spis[0], ahinfo->spis[1],
+	return spi_match(ahinfo->spis[0], ahinfo->spis[1],
 			  ntohl(ah->spi),
 			  !!(ahinfo->invflags & IP6T_AH_INV_SPI)) &&
 		(!ahinfo->hdrlen ||
diff --git a/net/ipv6/netfilter/ip6t_frag.c b/net/ipv6/netfilter/ip6t_frag.c
index fb91eeee4a1e..3aad6439386b 100644
--- a/net/ipv6/netfilter/ip6t_frag.c
+++ b/net/ipv6/netfilter/ip6t_frag.c
@@ -85,8 +85,7 @@ frag_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		 !((fraginfo->flags & IP6T_FRAG_NMF) &&
 		   (ntohs(fh->frag_off) & IP6_MF)));
 
-	return (fh != NULL) &&
-		id_match(fraginfo->ids[0], fraginfo->ids[1],
+	return id_match(fraginfo->ids[0], fraginfo->ids[1],
 			 ntohl(fh->identification),
 			 !!(fraginfo->invflags & IP6T_FRAG_INV_IDS)) &&
 		!((fraginfo->flags & IP6T_FRAG_RES) &&
diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c
index 467b2a86031b..e7a3fb9355ee 100644
--- a/net/ipv6/netfilter/ip6t_hbh.c
+++ b/net/ipv6/netfilter/ip6t_hbh.c
@@ -86,8 +86,7 @@ hbh_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		  ((optinfo->hdrlen == hdrlen) ^
 		   !!(optinfo->invflags & IP6T_OPTS_INV_LEN))));
 
-	ret = (oh != NULL) &&
-	      (!(optinfo->flags & IP6T_OPTS_LEN) ||
+	ret = (!(optinfo->flags & IP6T_OPTS_LEN) ||
 	       ((optinfo->hdrlen == hdrlen) ^
 		!!(optinfo->invflags & IP6T_OPTS_INV_LEN)));
 
diff --git a/net/ipv6/netfilter/ip6t_rt.c b/net/ipv6/netfilter/ip6t_rt.c
index f633dc84ca3f..733c83d38b30 100644
--- a/net/ipv6/netfilter/ip6t_rt.c
+++ b/net/ipv6/netfilter/ip6t_rt.c
@@ -89,8 +89,7 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		 !((rtinfo->flags & IP6T_RT_RES) &&
 		   (((const struct rt0_hdr *)rh)->reserved)));
 
-	ret = (rh != NULL) &&
-	      (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
+	ret = (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
 			      rh->segments_left,
 			      !!(rtinfo->invflags & IP6T_RT_INV_SGS))) &&
 	      (!(rtinfo->flags & IP6T_RT_LEN) ||
-- 
2.20.1

[PATCH 6/7] netfilter: nf_tables: extended netlink error reporting for expressions

[Pablo Neira Ayuso]

This patch extends 36dd1bcc07e5 ("netfilter: nf_tables: initial support
for extended ACK reporting") to include netlink extended error reporting
for expressions. This allows userspace to identify what rule expression
is triggering the error.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0d96e4eb754d..fac552b0179f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2509,6 +2509,7 @@ int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
 
 struct nft_expr_info {
 	const struct nft_expr_ops	*ops;
+	const struct nlattr		*attr;
 	struct nlattr			*tb[NFT_EXPR_MAXATTR + 1];
 };
 
@@ -2556,7 +2557,9 @@ static int nf_tables_expr_parse(const struct nft_ctx *ctx,
 	} else
 		ops = type->ops;
 
+	info->attr = nla;
 	info->ops = ops;
+
 	return 0;
 
 err1:
@@ -3214,8 +3217,10 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
 	expr = nft_expr_first(rule);
 	for (i = 0; i < n; i++) {
 		err = nf_tables_newexpr(&ctx, &info[i], expr);
-		if (err < 0)
+		if (err < 0) {
+			NL_SET_BAD_ATTR(extack, info[i].attr);
 			goto err2;
+		}
 
 		if (info[i].ops->validate)
 			nft_validate_state_update(net, NFT_VALIDATE_NEED);
-- 
2.20.1

[PATCH 7/7] netfilter: nf_tables: report EEXIST on overlaps

[Pablo Neira Ayuso]

Replace EBUSY by EEXIST in the following cases:

- If the user adds a chain with a different configuration such as different
  type, hook and priority.

- If the user adds a non-base chain that clashes with an existing basechain.

- If the user adds a { key : value } mapping element and the key exists
  but the value differs.

- If the device already belongs to an existing flowtable.

User describe that this error reporting is confusing:

- https://bugzilla.netfilter.org/show_bug.cgi?id=1176
- https://bugzilla.netfilter.org/show_bug.cgi?id=1413

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index fac552b0179f..6571789989bc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2097,7 +2097,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
 
 	if (nla[NFTA_CHAIN_HOOK]) {
 		if (!nft_is_base_chain(chain))
-			return -EBUSY;
+			return -EEXIST;
 
 		err = nft_chain_parse_hook(ctx->net, nla, &hook, ctx->family,
 					   false);
@@ -2107,21 +2107,21 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
 		basechain = nft_base_chain(chain);
 		if (basechain->type != hook.type) {
 			nft_chain_release_hook(&hook);
-			return -EBUSY;
+			return -EEXIST;
 		}
 
 		if (ctx->family == NFPROTO_NETDEV) {
 			if (!nft_hook_list_equal(&basechain->hook_list,
 						 &hook.list)) {
 				nft_chain_release_hook(&hook);
-				return -EBUSY;
+				return -EEXIST;
 			}
 		} else {
 			ops = &basechain->ops;
 			if (ops->hooknum != hook.num ||
 			    ops->priority != hook.priority) {
 				nft_chain_release_hook(&hook);
-				return -EBUSY;
+				return -EEXIST;
 			}
 		}
 		nft_chain_release_hook(&hook);
@@ -5262,10 +5262,8 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA) ^
 			    nft_set_ext_exists(ext2, NFT_SET_EXT_DATA) ||
 			    nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF) ^
-			    nft_set_ext_exists(ext2, NFT_SET_EXT_OBJREF)) {
-				err = -EBUSY;
+			    nft_set_ext_exists(ext2, NFT_SET_EXT_OBJREF))
 				goto err_element_clash;
-			}
 			if ((nft_set_ext_exists(ext, NFT_SET_EXT_DATA) &&
 			     nft_set_ext_exists(ext2, NFT_SET_EXT_DATA) &&
 			     memcmp(nft_set_ext_data(ext),
@@ -5273,7 +5271,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			    (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF) &&
 			     nft_set_ext_exists(ext2, NFT_SET_EXT_OBJREF) &&
 			     *nft_set_ext_obj(ext) != *nft_set_ext_obj(ext2)))
-				err = -EBUSY;
+				goto err_element_clash;
 			else if (!(nlmsg_flags & NLM_F_EXCL))
 				err = 0;
 		} else if (err == -ENOTEMPTY) {
@@ -6423,7 +6421,7 @@ static int nft_register_flowtable_net_hooks(struct net *net,
 			list_for_each_entry(hook2, &ft->hook_list, list) {
 				if (hook->ops.dev == hook2->ops.dev &&
 				    hook->ops.pf == hook2->ops.pf) {
-					err = -EBUSY;
+					err = -EEXIST;
 					goto err_unregister_net_hooks;
 				}
 			}
-- 
2.20.1

Re: [PATCH 0/7] Netfilter updates for net-next

[David Miller]

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Sun,  2 Aug 2020 20:31:41 +0200

> 1) UAF in chain binding support from previous batch, from Dan Carpenter.
> 
> 2) Queue up delayed work to expire connections with no destination,
>    from Andrew Sy Kim.
> 
> 3) Use fallthrough pseudo-keyword, from Gustavo A. R. Silva.
> 
> 4) Replace HTTP links with HTTPS, from Alexander A. Klimov.
> 
> 5) Remove superfluous null header checks in ip6tables, from
>    Gaurav Singh.
> 
> 6) Add extended netlink error reporting for expression.
> 
> 7) Report EEXIST on overlapping chain, set elements and flowtable
>    devices.
> 
> Please, pull these changes from:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git

Pulled, thank you.