From fd3e71a9f71e232181a225301a75936373636ccc Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Mon, 5 Nov 2018 03:43:19 +0900
Subject: [PATCH 01/16] netfilter: nf_conncount: use spin_lock_bh instead of
 spin_lock

conn_free() holds lock with spin_lock() and it is called by both
nf_conncount_lookup() and nf_conncount_gc_list(). nf_conncount_lookup()
is called from bottom-half context and nf_conncount_gc_list() from
process context. So that spin_lock() call is not safe. Hence
conn_free() should use spin_lock_bh() instead of spin_lock().

test commands:
   %nft add table ip filter
   %nft add chain ip filter input { type filter hook input priority 0\; }
   %nft add rule filter input meter test { ip saddr ct count over 2 } \
	   counter

splat looks like:
[  461.996507] ================================
[  461.998999] WARNING: inconsistent lock state
[  461.998999] 4.19.0-rc6+ #22 Not tainted
[  461.998999] --------------------------------
[  461.998999] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  461.998999] kworker/0:2/134 [HC0[0]:SC0[0]:HE1:SE1] takes:
[  461.998999] 00000000a71a559a (&(&list->list_lock)->rlock){+.?.}, at: conn_free+0x69/0x2b0 [nf_conncount]
[  461.998999] {IN-SOFTIRQ-W} state was registered at:
[  461.998999]   _raw_spin_lock+0x30/0x70
[  461.998999]   nf_conncount_add+0x28a/0x520 [nf_conncount]
[  461.998999]   nft_connlimit_eval+0x401/0x580 [nft_connlimit]
[  461.998999]   nft_dynset_eval+0x32b/0x590 [nf_tables]
[  461.998999]   nft_do_chain+0x497/0x1430 [nf_tables]
[  461.998999]   nft_do_chain_ipv4+0x255/0x330 [nf_tables]
[  461.998999]   nf_hook_slow+0xb1/0x160
[ ... ]
[  461.998999] other info that might help us debug this:
[  461.998999]  Possible unsafe locking scenario:
[  461.998999]
[  461.998999]        CPU0
[  461.998999]        ----
[  461.998999]   lock(&(&list->list_lock)->rlock);
[  461.998999]   <Interrupt>
[  461.998999]     lock(&(&list->list_lock)->rlock);
[  461.998999]
[  461.998999]  *** DEADLOCK ***
[  461.998999]
[ ... ]

Fixes: 5c789e131cbb ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conncount.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index 02ca7df793f5..71b1f4f99580 100644
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -106,15 +106,15 @@ nf_conncount_add(struct nf_conncount_list *list,
 	conn->zone = *zone;
 	conn->cpu = raw_smp_processor_id();
 	conn->jiffies32 = (u32)jiffies;
-	spin_lock(&list->list_lock);
+	spin_lock_bh(&list->list_lock);
 	if (list->dead == true) {
 		kmem_cache_free(conncount_conn_cachep, conn);
-		spin_unlock(&list->list_lock);
+		spin_unlock_bh(&list->list_lock);
 		return NF_CONNCOUNT_SKIP;
 	}
 	list_add_tail(&conn->node, &list->head);
 	list->count++;
-	spin_unlock(&list->list_lock);
+	spin_unlock_bh(&list->list_lock);
 	return NF_CONNCOUNT_ADDED;
 }
 EXPORT_SYMBOL_GPL(nf_conncount_add);
@@ -132,10 +132,10 @@ static bool conn_free(struct nf_conncount_list *list,
 {
 	bool free_entry = false;
 
-	spin_lock(&list->list_lock);
+	spin_lock_bh(&list->list_lock);
 
 	if (list->count == 0) {
-		spin_unlock(&list->list_lock);
+		spin_unlock_bh(&list->list_lock);
                 return free_entry;
 	}
 
@@ -144,7 +144,7 @@ static bool conn_free(struct nf_conncount_list *list,
 	if (list->count == 0)
 		free_entry = true;
 
-	spin_unlock(&list->list_lock);
+	spin_unlock_bh(&list->list_lock);
 	call_rcu(&conn->rcu_head, __conn_free);
 	return free_entry;
 }

From 31568ec09ea02a050249921698c9729419539cce Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Mon, 5 Nov 2018 03:44:11 +0900
Subject: [PATCH 02/16] netfilter: nf_conncount: fix list_del corruption in
 conn_free

nf_conncount_tuple is an element of nft_connlimit and that is deleted by
conn_free(). Elements can be deleted by both GC routine and data path
functions (nf_conncount_lookup, nf_conncount_add) and they call
conn_free() to free elements. But conn_free() only protects lists, not
each element. So that list_del corruption could occurred.

The conn_free() doesn't check whether element is already deleted. In
order to protect elements, dead flag is added. If an element is deleted,
dead flag is set. The only conn_free() can delete elements so that both
list lock and dead flag are enough to protect it.

test commands:
   %nft add table ip filter
   %nft add chain ip filter input { type filter hook input priority 0\; }
   %nft add rule filter input meter test { ip id ct count over 2 } counter

splat looks like:
[ 1779.495778] list_del corruption, ffff8800b6e12008->prev is LIST_POISON2 (dead000000000200)
[ 1779.505453] ------------[ cut here ]------------
[ 1779.506260] kernel BUG at lib/list_debug.c:50!
[ 1779.515831] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 1779.516772] CPU: 0 PID: 33 Comm: kworker/0:2 Not tainted 4.19.0-rc6+ #22
[ 1779.516772] Workqueue: events_power_efficient nft_rhash_gc [nf_tables_set]
[ 1779.516772] RIP: 0010:__list_del_entry_valid+0xd8/0x150
[ 1779.516772] Code: 39 48 83 c4 08 b8 01 00 00 00 5b 5d c3 48 89 ea 48 c7 c7 00 c3 5b 98 e8 0f dc 40 ff 0f 0b 48 c7 c7 60 c3 5b 98 e8 01 dc 40 ff <0f> 0b 48 c7 c7 c0 c3 5b 98 e8 f3 db 40 ff 0f 0b 48 c7 c7 20 c4 5b
[ 1779.516772] RSP: 0018:ffff880119127420 EFLAGS: 00010286
[ 1779.516772] RAX: 000000000000004e RBX: dead000000000200 RCX: 0000000000000000
[ 1779.516772] RDX: 000000000000004e RSI: 0000000000000008 RDI: ffffed0023224e7a
[ 1779.516772] RBP: ffff88011934bc10 R08: ffffed002367cea9 R09: ffffed002367cea9
[ 1779.516772] R10: 0000000000000001 R11: ffffed002367cea8 R12: ffff8800b6e12008
[ 1779.516772] R13: ffff8800b6e12010 R14: ffff88011934bc20 R15: ffff8800b6e12008
[ 1779.516772] FS:  0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000
[ 1779.516772] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1779.516772] CR2: 00007fc876534010 CR3: 000000010da16000 CR4: 00000000001006f0
[ 1779.516772] Call Trace:
[ 1779.516772]  conn_free+0x9f/0x2b0 [nf_conncount]
[ 1779.516772]  ? nf_ct_tmpl_alloc+0x2a0/0x2a0 [nf_conntrack]
[ 1779.516772]  ? nf_conncount_add+0x520/0x520 [nf_conncount]
[ 1779.516772]  ? do_raw_spin_trylock+0x1a0/0x1a0
[ 1779.516772]  ? do_raw_spin_trylock+0x10/0x1a0
[ 1779.516772]  find_or_evict+0xe5/0x150 [nf_conncount]
[ 1779.516772]  nf_conncount_gc_list+0x162/0x360 [nf_conncount]
[ 1779.516772]  ? nf_conncount_lookup+0xee0/0xee0 [nf_conncount]
[ 1779.516772]  ? _raw_spin_unlock_irqrestore+0x45/0x50
[ 1779.516772]  ? trace_hardirqs_off+0x6b/0x220
[ 1779.516772]  ? trace_hardirqs_on_caller+0x220/0x220
[ 1779.516772]  nft_rhash_gc+0x16b/0x540 [nf_tables_set]
[ ... ]

Fixes: 5c789e131cbb ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conncount.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index 71b1f4f99580..cb33709138df 100644
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -49,6 +49,7 @@ struct nf_conncount_tuple {
 	struct nf_conntrack_zone	zone;
 	int				cpu;
 	u32				jiffies32;
+	bool				dead;
 	struct rcu_head			rcu_head;
 };
 
@@ -106,6 +107,7 @@ nf_conncount_add(struct nf_conncount_list *list,
 	conn->zone = *zone;
 	conn->cpu = raw_smp_processor_id();
 	conn->jiffies32 = (u32)jiffies;
+	conn->dead = false;
 	spin_lock_bh(&list->list_lock);
 	if (list->dead == true) {
 		kmem_cache_free(conncount_conn_cachep, conn);
@@ -134,12 +136,13 @@ static bool conn_free(struct nf_conncount_list *list,
 
 	spin_lock_bh(&list->list_lock);
 
-	if (list->count == 0) {
+	if (conn->dead) {
 		spin_unlock_bh(&list->list_lock);
-                return free_entry;
+		return free_entry;
 	}
 
 	list->count--;
+	conn->dead = true;
 	list_del_rcu(&conn->node);
 	if (list->count == 0)
 		free_entry = true;

From 3c5cdb17c3be76714dfd0d03e384f70579545614 Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Mon, 5 Nov 2018 03:44:39 +0900
Subject: [PATCH 03/16] netfilter: nf_conncount: fix unexpected permanent node
 of list.

When list->count is 0, the list is deleted by GC. But list->count is
never reached 0 because initial count value is 1 and it is increased
when node is inserted. So that initial value of list->count should be 0.

Originally GC always finds zero count list through deleting node and
decreasing count. However, list may be left empty since node insertion
may fail eg.  allocaton problem. In order to solve this problem, GC
routine also finds zero count list without deleting node.

Fixes: cb2b36f5a97d ("netfilter: nf_conncount: Switch to plain list")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conncount.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index cb33709138df..8acae4a3e4c0 100644
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -144,8 +144,10 @@ static bool conn_free(struct nf_conncount_list *list,
 	list->count--;
 	conn->dead = true;
 	list_del_rcu(&conn->node);
-	if (list->count == 0)
+	if (list->count == 0) {
+		list->dead = true;
 		free_entry = true;
+	}
 
 	spin_unlock_bh(&list->list_lock);
 	call_rcu(&conn->rcu_head, __conn_free);
@@ -248,7 +250,7 @@ void nf_conncount_list_init(struct nf_conncount_list *list)
 {
 	spin_lock_init(&list->list_lock);
 	INIT_LIST_HEAD(&list->head);
-	list->count = 1;
+	list->count = 0;
 	list->dead = false;
 }
 EXPORT_SYMBOL_GPL(nf_conncount_list_init);
@@ -262,6 +264,7 @@ bool nf_conncount_gc_list(struct net *net,
 	struct nf_conn *found_ct;
 	unsigned int collected = 0;
 	bool free_entry = false;
+	bool ret = false;
 
 	list_for_each_entry_safe(conn, conn_n, &list->head, node) {
 		found = find_or_evict(net, list, conn, &free_entry);
@@ -291,7 +294,15 @@ bool nf_conncount_gc_list(struct net *net,
 		if (collected > CONNCOUNT_GC_MAX_NODES)
 			return false;
 	}
-	return false;
+
+	spin_lock_bh(&list->list_lock);
+	if (!list->count) {
+		list->dead = true;
+		ret = true;
+	}
+	spin_unlock_bh(&list->list_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_conncount_gc_list);
 
@@ -417,6 +428,7 @@ insert_tree(struct net *net,
 	nf_conncount_list_init(&rbconn->list);
 	list_add(&conn->node, &rbconn->list.head);
 	count = 1;
+	rbconn->list.count = count;
 
 	rb_link_node(&rbconn->node, parent, rbnode);
 	rb_insert_color(&rbconn->node, root);

From 0fb39bbe43d4481fcf300d2b5822de60942fd189 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Wed, 31 Oct 2018 18:26:20 +0100
Subject: [PATCH 04/16] netfilter: nf_tables: don't skip inactive chains during
 update

There is no synchronization between packet path and the configuration plane.

The packet path uses two arrays with rules, one contains the current (active)
generation.  The other either contains the last (obsolete) generation or
the future one.

Consider:
cpu1               cpu2
                   nft_do_chain(c);
delete c
net->gen++;
                   genbit = !!net->gen;
                   rules = c->rg[genbit];

cpu1 ignores c when updating if c is not active anymore in the new
generation.

On cpu2, we now use rules from wrong generation, as c->rg[old]
contains the rules matching 'c' whereas c->rg[new] was not updated and
can even point to rules that have been free'd already, causing a crash.

To fix this, make sure that 'current' to the 'next' generation are
identical for chains that are going away so that c->rg[new] will just
use the matching rules even if genbit was incremented already.

Fixes: 0cbc06b3faba7 ("netfilter: nf_tables: remove synchronize_rcu in commit phase")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 42487d01a3ed..dd577e7d100c 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6324,7 +6324,7 @@ static void nf_tables_commit_chain_free_rules_old(struct nft_rule **rules)
 	call_rcu(&old->h, __nf_tables_commit_chain_free_rules_old);
 }
 
-static void nf_tables_commit_chain_active(struct net *net, struct nft_chain *chain)
+static void nf_tables_commit_chain(struct net *net, struct nft_chain *chain)
 {
 	struct nft_rule **g0, **g1;
 	bool next_genbit;
@@ -6441,11 +6441,8 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 
 	/* step 2.  Make rules_gen_X visible to packet path */
 	list_for_each_entry(table, &net->nft.tables, list) {
-		list_for_each_entry(chain, &table->chains, list) {
-			if (!nft_is_active_next(net, chain))
-				continue;
-			nf_tables_commit_chain_active(net, chain);
-		}
+		list_for_each_entry(chain, &table->chains, list)
+			nf_tables_commit_chain(net, chain);
 	}
 
 	/*

From 25d8bcedbf4329895dbaf9dd67baa6f18dad918c Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Wed, 31 Oct 2018 18:26:21 +0100
Subject: [PATCH 05/16] selftests: add script to stress-test nft packet path
 vs. control plane

Start flood ping for each cpu while loading/flushing rulesets to make
sure we do not access already-free'd rules from nf_tables evaluation loop.

Also add this to TARGETS so 'make run_tests' in selftest dir runs it
automatically.

This would have caught the bug fixed in previous change
("netfilter: nf_tables: do not skip inactive chains during generation update")
sooner.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 tools/testing/selftests/Makefile              |  1 +
 tools/testing/selftests/netfilter/Makefile    |  6 ++
 tools/testing/selftests/netfilter/config      |  2 +
 .../selftests/netfilter/nft_trans_stress.sh   | 78 +++++++++++++++++++
 4 files changed, 87 insertions(+)
 create mode 100644 tools/testing/selftests/netfilter/Makefile
 create mode 100644 tools/testing/selftests/netfilter/config
 create mode 100755 tools/testing/selftests/netfilter/nft_trans_stress.sh

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index f1fe492c8e17..f0017c831e57 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -24,6 +24,7 @@ TARGETS += memory-hotplug
 TARGETS += mount
 TARGETS += mqueue
 TARGETS += net
+TARGETS += netfilter
 TARGETS += nsfs
 TARGETS += powerpc
 TARGETS += proc
diff --git a/tools/testing/selftests/netfilter/Makefile b/tools/testing/selftests/netfilter/Makefile
new file mode 100644
index 000000000000..47ed6cef93fb
--- /dev/null
+++ b/tools/testing/selftests/netfilter/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for netfilter selftests
+
+TEST_PROGS := nft_trans_stress.sh
+
+include ../lib.mk
diff --git a/tools/testing/selftests/netfilter/config b/tools/testing/selftests/netfilter/config
new file mode 100644
index 000000000000..1017313e41a8
--- /dev/null
+++ b/tools/testing/selftests/netfilter/config
@@ -0,0 +1,2 @@
+CONFIG_NET_NS=y
+NF_TABLES_INET=y
diff --git a/tools/testing/selftests/netfilter/nft_trans_stress.sh b/tools/testing/selftests/netfilter/nft_trans_stress.sh
new file mode 100755
index 000000000000..f1affd12c4b1
--- /dev/null
+++ b/tools/testing/selftests/netfilter/nft_trans_stress.sh
@@ -0,0 +1,78 @@
+#!/bin/bash
+#
+# This test is for stress-testing the nf_tables config plane path vs.
+# packet path processing: Make sure we never release rules that are
+# still visible to other cpus.
+#
+# set -e
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+testns=testns1
+tables="foo bar baz quux"
+
+nft --version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not run test without nft tool"
+	exit $ksft_skip
+fi
+
+ip -Version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not run test without ip tool"
+	exit $ksft_skip
+fi
+
+tmp=$(mktemp)
+
+for table in $tables; do
+	echo add table inet "$table" >> "$tmp"
+	echo flush table inet "$table" >> "$tmp"
+
+	echo "add chain inet $table INPUT { type filter hook input priority 0; }" >> "$tmp"
+	echo "add chain inet $table OUTPUT { type filter hook output priority 0; }" >> "$tmp"
+	for c in $(seq 1 400); do
+		chain=$(printf "chain%03u" "$c")
+		echo "add chain inet $table $chain" >> "$tmp"
+	done
+
+	for c in $(seq 1 400); do
+		chain=$(printf "chain%03u" "$c")
+		for BASE in INPUT OUTPUT; do
+			echo "add rule inet $table $BASE counter jump $chain" >> "$tmp"
+		done
+		echo "add rule inet $table $chain counter return" >> "$tmp"
+	done
+done
+
+ip netns add "$testns"
+ip -netns "$testns" link set lo up
+
+lscpu | grep ^CPU\(s\): | ( read cpu cpunum ;
+cpunum=$((cpunum-1))
+for i in $(seq 0 $cpunum);do
+	mask=$(printf 0x%x $((1<<$i)))
+        ip netns exec "$testns" taskset $mask ping -4 127.0.0.1 -fq > /dev/null &
+        ip netns exec "$testns" taskset $mask ping -6 ::1 -fq > /dev/null &
+done)
+
+sleep 1
+
+for i in $(seq 1 10) ; do ip netns exec "$testns" nft -f "$tmp" & done
+
+for table in $tables;do
+	randsleep=$((RANDOM%10))
+	sleep $randsleep
+	ip netns exec "$testns" nft delete table inet $table 2>/dev/null
+done
+
+randsleep=$((RANDOM%10))
+sleep $randsleep
+
+pkill -9 ping
+
+wait
+
+rm -f "$tmp"
+ip netns del "$testns"

From 447750f281abef547be44fdcfe3bc4447b3115a8 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Sun, 4 Nov 2018 12:07:14 +0100
Subject: [PATCH 06/16] netfilter: nf_tables: don't use position attribute on
 rule replacement

Its possible to set both HANDLE and POSITION when replacing a rule.
In this case, the rule at POSITION gets replaced using the
userspace-provided handle.  Rule handles are supposed to be generated
by the kernel only.

Duplicate handles should be harmless, however better disable this "feature"
by only checking for the POSITION attribute on insert operations.

Fixes: 5e94846686d0 ("netfilter: nf_tables: add insert operation")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index dd577e7d100c..e496030fdc3b 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2589,17 +2589,14 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
 
 		if (chain->use == UINT_MAX)
 			return -EOVERFLOW;
-	}
 
-	if (nla[NFTA_RULE_POSITION]) {
-		if (!(nlh->nlmsg_flags & NLM_F_CREATE))
-			return -EOPNOTSUPP;
-
-		pos_handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_POSITION]));
-		old_rule = __nft_rule_lookup(chain, pos_handle);
-		if (IS_ERR(old_rule)) {
-			NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_POSITION]);
-			return PTR_ERR(old_rule);
+		if (nla[NFTA_RULE_POSITION]) {
+			pos_handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_POSITION]));
+			old_rule = __nft_rule_lookup(chain, pos_handle);
+			if (IS_ERR(old_rule)) {
+				NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_POSITION]);
+				return PTR_ERR(old_rule);
+			}
 		}
 	}
 

From 0fbcc5b568edab7d848b7c7fa66d44ffbd4133c0 Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Fri, 19 Oct 2018 00:27:57 +0900
Subject: [PATCH 07/16] netfilter: xt_RATEEST: remove netns exit routine

xt_rateest_net_exit() was added to check whether rules are flushed
successfully. but ->net_exit() callback is called earlier than
->destroy() callback.
So that ->net_exit() callback can't check that.

test commands:
   %ip netns add vm1
   %ip netns exec vm1 iptables -t mangle -I PREROUTING -p udp \
	   --dport 1111 -j RATEEST --rateest-name ap \
	   --rateest-interval 250ms --rateest-ewma 0.5s
   %ip netns del vm1

splat looks like:
[  668.813518] WARNING: CPU: 0 PID: 87 at net/netfilter/xt_RATEEST.c:210 xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Modules linked in: xt_RATEEST xt_tcpudp iptable_mangle bpfilter ip_tables x_tables
[  668.813518] CPU: 0 PID: 87 Comm: kworker/u4:2 Not tainted 4.19.0-rc7+ #21
[  668.813518] Workqueue: netns cleanup_net
[  668.813518] RIP: 0010:xt_rateest_net_exit+0x210/0x340 [xt_RATEEST]
[  668.813518] Code: 00 48 8b 85 30 ff ff ff 4c 8b 23 80 38 00 0f 85 24 01 00 00 48 8b 85 30 ff ff ff 4d 85 e4 4c 89 a5 58 ff ff ff c6 00 f8 74 b2 <0f> 0b 48 83 c3 08 4c 39 f3 75 b0 48 b8 00 00 00 00 00 fc ff df 49
[  668.813518] RSP: 0018:ffff8801156c73f8 EFLAGS: 00010282
[  668.813518] RAX: ffffed0022ad8e85 RBX: ffff880118928e98 RCX: 5db8012a00000000
[  668.813518] RDX: ffff8801156c7428 RSI: 00000000cb1d185f RDI: ffff880115663b74
[  668.813518] RBP: ffff8801156c74d0 R08: ffff8801156633c0 R09: 1ffff100236440be
[  668.813518] R10: 0000000000000001 R11: ffffed002367d852 R12: ffff880115142b08
[  668.813518] R13: 1ffff10022ad8e81 R14: ffff880118928ea8 R15: dffffc0000000000
[  668.813518] FS:  0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000
[  668.813518] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  668.813518] CR2: 0000563aa69f4f28 CR3: 0000000105a16000 CR4: 00000000001006f0
[  668.813518] Call Trace:
[  668.813518]  ? unregister_netdevice_many+0xe0/0xe0
[  668.813518]  ? xt_rateest_net_init+0x2c0/0x2c0 [xt_RATEEST]
[  668.813518]  ? default_device_exit+0x1ca/0x270
[  668.813518]  ? remove_proc_entry+0x1cd/0x390
[  668.813518]  ? dev_change_net_namespace+0xd00/0xd00
[  668.813518]  ? __init_waitqueue_head+0x130/0x130
[  668.813518]  ops_exit_list.isra.10+0x94/0x140
[  668.813518]  cleanup_net+0x45b/0x900
[  668.813518]  ? net_drop_ns+0x110/0x110
[  668.813518]  ? swapgs_restore_regs_and_return_to_usermode+0x3c/0x80
[  668.813518]  ? save_trace+0x300/0x300
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? lock_acquire+0x196/0x470
[  668.813518]  ? process_one_work+0xb60/0x1de0
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? _raw_spin_unlock_irq+0x29/0x40
[  668.813518]  ? __lock_acquire+0x4500/0x4500
[  668.813518]  ? __lock_is_held+0xb4/0x140
[  668.813518]  process_one_work+0xc13/0x1de0
[  668.813518]  ? pwq_dec_nr_in_flight+0x3c0/0x3c0
[  668.813518]  ? set_load_weight+0x270/0x270
[ ... ]

Fixes: 3427b2ab63fa ("netfilter: make xt_rateest hash table per net")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_RATEEST.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index dec843cadf46..9e05c86ba5c4 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c
@@ -201,18 +201,8 @@ static __net_init int xt_rateest_net_init(struct net *net)
 	return 0;
 }
 
-static void __net_exit xt_rateest_net_exit(struct net *net)
-{
-	struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(xn->hash); i++)
-		WARN_ON_ONCE(!hlist_empty(&xn->hash[i]));
-}
-
 static struct pernet_operations xt_rateest_net_ops = {
 	.init = xt_rateest_net_init,
-	.exit = xt_rateest_net_exit,
 	.id   = &xt_rateest_id,
 	.size = sizeof(struct xt_rateest_net),
 };

From 29e3880109e357fdc607b4393f8308cef6af9413 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Mon, 12 Nov 2018 22:43:45 +0100
Subject: [PATCH 08/16] netfilter: nf_tables: fix use-after-free when deleting
 compat expressions

nft_compat ops do not have static storage duration, unlike all other
expressions.

When nf_tables_expr_destroy() returns, expr->ops might have been
free'd already, so we need to store next address before calling
expression destructor.

For same reason, we can't deref match pointer after nft_xt_put().

This can be easily reproduced by adding msleep() before
nft_match_destroy() returns.

Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables")
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 5 +++--
 net/netfilter/nft_compat.c    | 3 ++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index e496030fdc3b..ddeaa1990e1e 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2457,7 +2457,7 @@ static int nf_tables_getrule(struct net *net, struct sock *nlsk,
 static void nf_tables_rule_destroy(const struct nft_ctx *ctx,
 				   struct nft_rule *rule)
 {
-	struct nft_expr *expr;
+	struct nft_expr *expr, *next;
 
 	/*
 	 * Careful: some expressions might not be initialized in case this
@@ -2465,8 +2465,9 @@ static void nf_tables_rule_destroy(const struct nft_ctx *ctx,
 	 */
 	expr = nft_expr_first(rule);
 	while (expr != nft_expr_last(rule) && expr->ops) {
+		next = nft_expr_next(expr);
 		nf_tables_expr_destroy(ctx, expr);
-		expr = nft_expr_next(expr);
+		expr = next;
 	}
 	kfree(rule);
 }
diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index 9d0ede474224..7334e0b80a5e 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -520,6 +520,7 @@ __nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr,
 		    void *info)
 {
 	struct xt_match *match = expr->ops->data;
+	struct module *me = match->me;
 	struct xt_mtdtor_param par;
 
 	par.net = ctx->net;
@@ -530,7 +531,7 @@ __nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr,
 		par.match->destroy(&par);
 
 	if (nft_xt_put(container_of(expr->ops, struct nft_xt, ops)))
-		module_put(match->me);
+		module_put(me);
 }
 
 static void

From b4e955e9f372035361fbc6f07b21fe2cc6a5be4a Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Fri, 16 Nov 2018 21:32:35 +0900
Subject: [PATCH 09/16] netfilter: xt_hashlimit: fix a possible memory leak in
 htable_create()

In the htable_create(), hinfo is allocated by vmalloc()
So that if error occurred, hinfo should be freed.

Fixes: 11d5f15723c9 ("netfilter: xt_hashlimit: Create revision 2 to support higher pps rates")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_hashlimit.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index 3e7d259e5d8d..1ad4017f9b73 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -295,9 +295,10 @@ static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg,
 
 	/* copy match config into hashtable config */
 	ret = cfg_copy(&hinfo->cfg, (void *)cfg, 3);
-
-	if (ret)
+	if (ret) {
+		vfree(hinfo);
 		return ret;
+	}
 
 	hinfo->cfg.size = size;
 	if (hinfo->cfg.max == 0)
@@ -814,7 +815,6 @@ hashlimit_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
 	int ret;
 
 	ret = cfg_copy(&cfg, (void *)&info->cfg, 1);
-
 	if (ret)
 		return ret;
 
@@ -830,7 +830,6 @@ hashlimit_mt_v2(const struct sk_buff *skb, struct xt_action_param *par)
 	int ret;
 
 	ret = cfg_copy(&cfg, (void *)&info->cfg, 2);
-
 	if (ret)
 		return ret;
 
@@ -921,7 +920,6 @@ static int hashlimit_mt_check_v1(const struct xt_mtchk_param *par)
 		return ret;
 
 	ret = cfg_copy(&cfg, (void *)&info->cfg, 1);
-
 	if (ret)
 		return ret;
 
@@ -940,7 +938,6 @@ static int hashlimit_mt_check_v2(const struct xt_mtchk_param *par)
 		return ret;
 
 	ret = cfg_copy(&cfg, (void *)&info->cfg, 2);
-
 	if (ret)
 		return ret;
 

From 2a31e4bd9ad255ee40809b5c798c4b1c2b09703b Mon Sep 17 00:00:00 2001
From: Xin Long <lucien.xin@gmail.com>
Date: Thu, 15 Nov 2018 15:14:30 +0800
Subject: [PATCH 10/16] ipvs: call ip_vs_dst_notifier earlier than
 ipv6_dev_notf

ip_vs_dst_event is supposed to clean up all dst used in ipvs'
destinations when a net dev is going down. But it works only
when the dst's dev is the same as the dev from the event.

Now with the same priority but late registration,
ip_vs_dst_notifier is always called later than ipv6_dev_notf
where the dst's dev is set to lo for NETDEV_DOWN event.

As the dst's dev lo is not the same as the dev from the event
in ip_vs_dst_event, ip_vs_dst_notifier doesn't actually work.
Also as these dst have to wait for dest_trash_timer to clean
them up. It would cause some non-permanent kernel warnings:

  unregister_netdevice: waiting for br0 to become free. Usage count = 3

To fix it, call ip_vs_dst_notifier earlier than ipv6_dev_notf
by increasing its priority to ADDRCONF_NOTIFY_PRIORITY + 5.

Note that for ipv4 route fib_netdev_notifier doesn't set dst's
dev to lo in NETDEV_DOWN event, so this fix is only needed when
IP_VS_IPV6 is defined.

Fixes: 7a4f0761fce3 ("IPVS: init and cleanup restructuring")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/ipvs/ip_vs_ctl.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 83395bf6dc35..432141f04af3 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3980,6 +3980,9 @@ static void __net_exit ip_vs_control_net_cleanup_sysctl(struct netns_ipvs *ipvs)
 
 static struct notifier_block ip_vs_dst_notifier = {
 	.notifier_call = ip_vs_dst_event,
+#ifdef CONFIG_IP_VS_IPV6
+	.priority = ADDRCONF_NOTIFY_PRIORITY + 5,
+#endif
 };
 
 int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)

From 89259088c1b7fecb43e8e245dc931909132a4e03 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Sat, 17 Nov 2018 11:32:29 +0100
Subject: [PATCH 11/16] netfilter: nfnetlink_cttimeout: fetch timeouts for
 udplite and gre, too

syzbot was able to trigger the WARN in cttimeout_default_get() by
passing UDPLITE as l4protocol.  Alias UDPLITE to UDP, both use
same timeout values.

Furthermore, also fetch GRE timeouts.  GRE is a bit more complicated,
as it still can be a module and its netns_proto_gre struct layout isn't
visible outside of the gre module. Can't move timeouts around, it
appears conntrack sysctl unregister assumes net_generic() returns
nf_proto_net, so we get crash. Expose layout of netns_proto_gre instead.

A followup nf-next patch could make gre tracker be built-in as well
if needed, its not that large.

Last, make the WARN() mention the missing protocol value in case
anything else is missing.

Reported-by: syzbot+2fae8fa157dd92618cae@syzkaller.appspotmail.com
Fixes: 8866df9264a3 ("netfilter: nfnetlink_cttimeout: pass default timeout policy to obj_to_nlattr")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/linux/netfilter/nf_conntrack_proto_gre.h | 13 +++++++++++++
 net/netfilter/nf_conntrack_proto_gre.c           | 14 ++------------
 net/netfilter/nfnetlink_cttimeout.c              | 15 +++++++++++++--
 3 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/include/linux/netfilter/nf_conntrack_proto_gre.h b/include/linux/netfilter/nf_conntrack_proto_gre.h
index b8d95564bd53..14edb795ab43 100644
--- a/include/linux/netfilter/nf_conntrack_proto_gre.h
+++ b/include/linux/netfilter/nf_conntrack_proto_gre.h
@@ -21,6 +21,19 @@ struct nf_ct_gre_keymap {
 	struct nf_conntrack_tuple tuple;
 };
 
+enum grep_conntrack {
+	GRE_CT_UNREPLIED,
+	GRE_CT_REPLIED,
+	GRE_CT_MAX
+};
+
+struct netns_proto_gre {
+	struct nf_proto_net	nf;
+	rwlock_t		keymap_lock;
+	struct list_head	keymap_list;
+	unsigned int		gre_timeouts[GRE_CT_MAX];
+};
+
 /* add new tuple->key_reply pair to keymap */
 int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
 			 struct nf_conntrack_tuple *t);
diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c
index 9b48dc8b4b88..2a5e56c6d8d9 100644
--- a/net/netfilter/nf_conntrack_proto_gre.c
+++ b/net/netfilter/nf_conntrack_proto_gre.c
@@ -43,24 +43,12 @@
 #include <linux/netfilter/nf_conntrack_proto_gre.h>
 #include <linux/netfilter/nf_conntrack_pptp.h>
 
-enum grep_conntrack {
-	GRE_CT_UNREPLIED,
-	GRE_CT_REPLIED,
-	GRE_CT_MAX
-};
-
 static const unsigned int gre_timeouts[GRE_CT_MAX] = {
 	[GRE_CT_UNREPLIED]	= 30*HZ,
 	[GRE_CT_REPLIED]	= 180*HZ,
 };
 
 static unsigned int proto_gre_net_id __read_mostly;
-struct netns_proto_gre {
-	struct nf_proto_net	nf;
-	rwlock_t		keymap_lock;
-	struct list_head	keymap_list;
-	unsigned int		gre_timeouts[GRE_CT_MAX];
-};
 
 static inline struct netns_proto_gre *gre_pernet(struct net *net)
 {
@@ -402,6 +390,8 @@ static int __init nf_ct_proto_gre_init(void)
 {
 	int ret;
 
+	BUILD_BUG_ON(offsetof(struct netns_proto_gre, nf) != 0);
+
 	ret = register_pernet_subsys(&proto_gre_net_ops);
 	if (ret < 0)
 		goto out_pernet;
diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c
index a518eb162344..109b0d27345a 100644
--- a/net/netfilter/nfnetlink_cttimeout.c
+++ b/net/netfilter/nfnetlink_cttimeout.c
@@ -455,7 +455,8 @@ static int cttimeout_default_get(struct net *net, struct sock *ctnl,
 	case IPPROTO_TCP:
 		timeouts = nf_tcp_pernet(net)->timeouts;
 		break;
-	case IPPROTO_UDP:
+	case IPPROTO_UDP: /* fallthrough */
+	case IPPROTO_UDPLITE:
 		timeouts = nf_udp_pernet(net)->timeouts;
 		break;
 	case IPPROTO_DCCP:
@@ -469,13 +470,23 @@ static int cttimeout_default_get(struct net *net, struct sock *ctnl,
 	case IPPROTO_SCTP:
 #ifdef CONFIG_NF_CT_PROTO_SCTP
 		timeouts = nf_sctp_pernet(net)->timeouts;
+#endif
+		break;
+	case IPPROTO_GRE:
+#ifdef CONFIG_NF_CT_PROTO_GRE
+		if (l4proto->net_id) {
+			struct netns_proto_gre *net_gre;
+
+			net_gre = net_generic(net, *l4proto->net_id);
+			timeouts = net_gre->gre_timeouts;
+		}
 #endif
 		break;
 	case 255:
 		timeouts = &nf_generic_pernet(net)->timeout;
 		break;
 	default:
-		WARN_ON_ONCE(1);
+		WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
 		break;
 	}
 

From 508b09046c0f21678652fb66fd1e9959d55591d2 Mon Sep 17 00:00:00 2001
From: Alin Nastac <alin.nastac@gmail.com>
Date: Wed, 21 Nov 2018 14:00:30 +0100
Subject: [PATCH 12/16] netfilter: ipv6: Preserve link scope traffic original
 oif

When ip6_route_me_harder is invoked, it resets outgoing interface of:
  - link-local scoped packets sent by neighbor discovery
  - multicast packets sent by MLD host
  - multicast packets send by MLD proxy daemon that sets outgoing
    interface through IPV6_PKTINFO ipi6_ifindex

Link-local and multicast packets must keep their original oif after
ip6_route_me_harder is called.

Signed-off-by: Alin Nastac <alin.nastac@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv6/netfilter.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 5ae8e1c51079..8b075f0bc351 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -24,7 +24,8 @@ int ip6_route_me_harder(struct net *net, struct sk_buff *skb)
 	unsigned int hh_len;
 	struct dst_entry *dst;
 	struct flowi6 fl6 = {
-		.flowi6_oif = sk ? sk->sk_bound_dev_if : 0,
+		.flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if :
+			rt6_need_strict(&iph->daddr) ? skb_dst(skb)->dev->ifindex : 0,
 		.flowi6_mark = skb->mark,
 		.flowi6_uid = sock_net_uid(net, sk),
 		.daddr = iph->daddr,

From 584eab291c67894cb17cc87544b9d086228ea70f Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Thu, 22 Nov 2018 19:59:46 +0900
Subject: [PATCH 13/16] netfilter: add missing error handling code for register
 functions

register_{netdevice/inetaddr/inet6addr}_notifier may return an error
value, this patch adds the code to handle these error paths.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 .../net/netfilter/ipv4/nf_nat_masquerade.h    |  2 +-
 .../net/netfilter/ipv6/nf_nat_masquerade.h    |  2 +-
 net/ipv4/netfilter/ipt_MASQUERADE.c           |  7 ++--
 net/ipv4/netfilter/nf_nat_masquerade_ipv4.c   | 21 +++++++++---
 net/ipv4/netfilter/nft_masq_ipv4.c            |  4 ++-
 net/ipv6/netfilter/ip6t_MASQUERADE.c          |  8 +++--
 net/ipv6/netfilter/nf_nat_masquerade_ipv6.c   | 32 +++++++++++++------
 net/ipv6/netfilter/nft_masq_ipv6.c            |  4 ++-
 net/netfilter/nft_flow_offload.c              |  5 ++-
 9 files changed, 63 insertions(+), 22 deletions(-)

diff --git a/include/net/netfilter/ipv4/nf_nat_masquerade.h b/include/net/netfilter/ipv4/nf_nat_masquerade.h
index cd24be4c4a99..13d55206bb9f 100644
--- a/include/net/netfilter/ipv4/nf_nat_masquerade.h
+++ b/include/net/netfilter/ipv4/nf_nat_masquerade.h
@@ -9,7 +9,7 @@ nf_nat_masquerade_ipv4(struct sk_buff *skb, unsigned int hooknum,
 		       const struct nf_nat_range2 *range,
 		       const struct net_device *out);
 
-void nf_nat_masquerade_ipv4_register_notifier(void);
+int nf_nat_masquerade_ipv4_register_notifier(void);
 void nf_nat_masquerade_ipv4_unregister_notifier(void);
 
 #endif /*_NF_NAT_MASQUERADE_IPV4_H_ */
diff --git a/include/net/netfilter/ipv6/nf_nat_masquerade.h b/include/net/netfilter/ipv6/nf_nat_masquerade.h
index 0c3b5ebf0bb8..2917bf95c437 100644
--- a/include/net/netfilter/ipv6/nf_nat_masquerade.h
+++ b/include/net/netfilter/ipv6/nf_nat_masquerade.h
@@ -5,7 +5,7 @@
 unsigned int
 nf_nat_masquerade_ipv6(struct sk_buff *skb, const struct nf_nat_range2 *range,
 		       const struct net_device *out);
-void nf_nat_masquerade_ipv6_register_notifier(void);
+int nf_nat_masquerade_ipv6_register_notifier(void);
 void nf_nat_masquerade_ipv6_unregister_notifier(void);
 
 #endif /* _NF_NAT_MASQUERADE_IPV6_H_ */
diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c
index ce1512b02cb2..fd3f9e8a74da 100644
--- a/net/ipv4/netfilter/ipt_MASQUERADE.c
+++ b/net/ipv4/netfilter/ipt_MASQUERADE.c
@@ -81,9 +81,12 @@ static int __init masquerade_tg_init(void)
 	int ret;
 
 	ret = xt_register_target(&masquerade_tg_reg);
+	if (ret)
+		return ret;
 
-	if (ret == 0)
-		nf_nat_masquerade_ipv4_register_notifier();
+	ret = nf_nat_masquerade_ipv4_register_notifier();
+	if (ret)
+		xt_unregister_target(&masquerade_tg_reg);
 
 	return ret;
 }
diff --git a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
index a9d5e013e555..c7d7fa4fc369 100644
--- a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
+++ b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
@@ -149,16 +149,29 @@ static struct notifier_block masq_inet_notifier = {
 
 static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);
 
-void nf_nat_masquerade_ipv4_register_notifier(void)
+int nf_nat_masquerade_ipv4_register_notifier(void)
 {
+	int ret;
+
 	/* check if the notifier was already set */
 	if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
-		return;
+		return 0;
 
 	/* Register for device down reports */
-	register_netdevice_notifier(&masq_dev_notifier);
+	ret = register_netdevice_notifier(&masq_dev_notifier);
+	if (ret)
+		goto err_dec;
 	/* Register IP address change reports */
-	register_inetaddr_notifier(&masq_inet_notifier);
+	ret = register_inetaddr_notifier(&masq_inet_notifier);
+	if (ret)
+		goto err_unregister;
+
+	return ret;
+err_unregister:
+	unregister_netdevice_notifier(&masq_dev_notifier);
+err_dec:
+	atomic_dec(&masquerade_notifier_refcount);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_register_notifier);
 
diff --git a/net/ipv4/netfilter/nft_masq_ipv4.c b/net/ipv4/netfilter/nft_masq_ipv4.c
index f1193e1e928a..6847de1d1db8 100644
--- a/net/ipv4/netfilter/nft_masq_ipv4.c
+++ b/net/ipv4/netfilter/nft_masq_ipv4.c
@@ -69,7 +69,9 @@ static int __init nft_masq_ipv4_module_init(void)
 	if (ret < 0)
 		return ret;
 
-	nf_nat_masquerade_ipv4_register_notifier();
+	ret = nf_nat_masquerade_ipv4_register_notifier();
+	if (ret)
+		nft_unregister_expr(&nft_masq_ipv4_type);
 
 	return ret;
 }
diff --git a/net/ipv6/netfilter/ip6t_MASQUERADE.c b/net/ipv6/netfilter/ip6t_MASQUERADE.c
index 491f808e356a..29c7f1915a96 100644
--- a/net/ipv6/netfilter/ip6t_MASQUERADE.c
+++ b/net/ipv6/netfilter/ip6t_MASQUERADE.c
@@ -58,8 +58,12 @@ static int __init masquerade_tg6_init(void)
 	int err;
 
 	err = xt_register_target(&masquerade_tg6_reg);
-	if (err == 0)
-		nf_nat_masquerade_ipv6_register_notifier();
+	if (err)
+		return err;
+
+	err = nf_nat_masquerade_ipv6_register_notifier();
+	if (err)
+		xt_unregister_target(&masquerade_tg6_reg);
 
 	return err;
 }
diff --git a/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
index 3e4bf2286abe..7afd1e63d2db 100644
--- a/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
+++ b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
@@ -132,8 +132,8 @@ static void iterate_cleanup_work(struct work_struct *work)
  * of ipv6 addresses being deleted), we also need to add an upper
  * limit to the number of queued work items.
  */
-static int masq_inet_event(struct notifier_block *this,
-			   unsigned long event, void *ptr)
+static int masq_inet6_event(struct notifier_block *this,
+			    unsigned long event, void *ptr)
 {
 	struct inet6_ifaddr *ifa = ptr;
 	const struct net_device *dev;
@@ -171,20 +171,34 @@ static int masq_inet_event(struct notifier_block *this,
 	return NOTIFY_DONE;
 }
 
-static struct notifier_block masq_inet_notifier = {
-	.notifier_call	= masq_inet_event,
+static struct notifier_block masq_inet6_notifier = {
+	.notifier_call	= masq_inet6_event,
 };
 
 static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);
 
-void nf_nat_masquerade_ipv6_register_notifier(void)
+int nf_nat_masquerade_ipv6_register_notifier(void)
 {
+	int ret;
+
 	/* check if the notifier is already set */
 	if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
-		return;
+		return 0;
 
-	register_netdevice_notifier(&masq_dev_notifier);
-	register_inet6addr_notifier(&masq_inet_notifier);
+	ret = register_netdevice_notifier(&masq_dev_notifier);
+	if (ret)
+		goto err_dec;
+
+	ret = register_inet6addr_notifier(&masq_inet6_notifier);
+	if (ret)
+		goto err_unregister;
+
+	return ret;
+err_unregister:
+	unregister_netdevice_notifier(&masq_dev_notifier);
+err_dec:
+	atomic_dec(&masquerade_notifier_refcount);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_register_notifier);
 
@@ -194,7 +208,7 @@ void nf_nat_masquerade_ipv6_unregister_notifier(void)
 	if (atomic_dec_return(&masquerade_notifier_refcount) > 0)
 		return;
 
-	unregister_inet6addr_notifier(&masq_inet_notifier);
+	unregister_inet6addr_notifier(&masq_inet6_notifier);
 	unregister_netdevice_notifier(&masq_dev_notifier);
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_unregister_notifier);
diff --git a/net/ipv6/netfilter/nft_masq_ipv6.c b/net/ipv6/netfilter/nft_masq_ipv6.c
index dd0122f3cffe..e06c82e9dfcd 100644
--- a/net/ipv6/netfilter/nft_masq_ipv6.c
+++ b/net/ipv6/netfilter/nft_masq_ipv6.c
@@ -70,7 +70,9 @@ static int __init nft_masq_ipv6_module_init(void)
 	if (ret < 0)
 		return ret;
 
-	nf_nat_masquerade_ipv6_register_notifier();
+	ret = nf_nat_masquerade_ipv6_register_notifier();
+	if (ret)
+		nft_unregister_expr(&nft_masq_ipv6_type);
 
 	return ret;
 }
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index e82d9a966c45..974525eb92df 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -214,7 +214,9 @@ static int __init nft_flow_offload_module_init(void)
 {
 	int err;
 
-	register_netdevice_notifier(&flow_offload_netdev_notifier);
+	err = register_netdevice_notifier(&flow_offload_netdev_notifier);
+	if (err)
+		goto err;
 
 	err = nft_register_expr(&nft_flow_offload_type);
 	if (err < 0)
@@ -224,6 +226,7 @@ static int __init nft_flow_offload_module_init(void)
 
 register_expr:
 	unregister_netdevice_notifier(&flow_offload_netdev_notifier);
+err:
 	return err;
 }
 

From 095faf45e64be00bff4da2d6182dface3d69c9b7 Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Thu, 22 Nov 2018 19:59:57 +0900
Subject: [PATCH 14/16] netfilter: nat: fix double register in masquerade
 modules

There is a reference counter to ensure that masquerade modules register
notifiers only once. However, the existing reference counter approach is
not safe, test commands are:

   while :
   do
   	   modprobe ip6t_MASQUERADE &
	   modprobe nft_masq_ipv6 &
	   modprobe -rv ip6t_MASQUERADE &
	   modprobe -rv nft_masq_ipv6 &
   done

numbers below represent the reference counter.
--------------------------------------------------------
CPU0        CPU1        CPU2        CPU3        CPU4
[insmod]    [insmod]    [rmmod]     [rmmod]     [insmod]
--------------------------------------------------------
0->1
register    1->2
            returns     2->1
			returns     1->0
                                                0->1
                                                register <--
                                    unregister
--------------------------------------------------------

The unregistation of CPU3 should be processed before the
registration of CPU4.

In order to fix this, use a mutex instead of reference counter.

splat looks like:
[  323.869557] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:1381]
[  323.869574] Modules linked in: nf_tables(+) nf_nat_ipv6(-) nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 n]
[  323.869574] irq event stamp: 194074
[  323.898930] hardirqs last  enabled at (194073): [<ffffffff90004a0d>] trace_hardirqs_on_thunk+0x1a/0x1c
[  323.898930] hardirqs last disabled at (194074): [<ffffffff90004a29>] trace_hardirqs_off_thunk+0x1a/0x1c
[  323.898930] softirqs last  enabled at (182132): [<ffffffff922006ec>] __do_softirq+0x6ec/0xa3b
[  323.898930] softirqs last disabled at (182109): [<ffffffff90193426>] irq_exit+0x1a6/0x1e0
[  323.898930] CPU: 0 PID: 1381 Comm: modprobe Not tainted 4.20.0-rc2+ #27
[  323.898930] RIP: 0010:raw_notifier_chain_register+0xea/0x240
[  323.898930] Code: 3c 03 0f 8e f2 00 00 00 44 3b 6b 10 7f 4d 49 bc 00 00 00 00 00 fc ff df eb 22 48 8d 7b 10 488
[  323.898930] RSP: 0018:ffff888101597218 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
[  323.898930] RAX: 0000000000000000 RBX: ffffffffc04361c0 RCX: 0000000000000000
[  323.898930] RDX: 1ffffffff26132ae RSI: ffffffffc04aa3c0 RDI: ffffffffc04361d0
[  323.898930] RBP: ffffffffc04361c8 R08: 0000000000000000 R09: 0000000000000001
[  323.898930] R10: ffff8881015972b0 R11: fffffbfff26132c4 R12: dffffc0000000000
[  323.898930] R13: 0000000000000000 R14: 1ffff110202b2e44 R15: ffffffffc04aa3c0
[  323.898930] FS:  00007f813ed41540(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
[  323.898930] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  323.898930] CR2: 0000559bf2c9f120 CR3: 000000010bc80000 CR4: 00000000001006f0
[  323.898930] Call Trace:
[  323.898930]  ? atomic_notifier_chain_register+0x2d0/0x2d0
[  323.898930]  ? down_read+0x150/0x150
[  323.898930]  ? sched_clock_cpu+0x126/0x170
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  323.898930]  register_netdevice_notifier+0xbb/0x790
[  323.898930]  ? __dev_close_many+0x2d0/0x2d0
[  323.898930]  ? __mutex_unlock_slowpath+0x17f/0x740
[  323.898930]  ? wait_for_completion+0x710/0x710
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  323.898930]  ? up_write+0x6c/0x210
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  324.127073]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  324.127073]  nft_chain_filter_init+0x1e/0xe8a [nf_tables]
[  324.127073]  nf_tables_module_init+0x37/0x92 [nf_tables]
[ ... ]

Fixes: 8dd33cc93ec9 ("netfilter: nf_nat: generalize IPv4 masquerading support for nf_tables")
Fixes: be6b635cd674 ("netfilter: nf_nat: generalize IPv6 masquerading support for nf_tables")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/nf_nat_masquerade_ipv4.c | 23 ++++++++++++++-------
 net/ipv6/netfilter/nf_nat_masquerade_ipv6.c | 23 ++++++++++++++-------
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
index c7d7fa4fc369..41327bb99093 100644
--- a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
+++ b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
@@ -147,15 +147,17 @@ static struct notifier_block masq_inet_notifier = {
 	.notifier_call	= masq_inet_event,
 };
 
-static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);
+static int masq_refcnt;
+static DEFINE_MUTEX(masq_mutex);
 
 int nf_nat_masquerade_ipv4_register_notifier(void)
 {
-	int ret;
+	int ret = 0;
 
+	mutex_lock(&masq_mutex);
 	/* check if the notifier was already set */
-	if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
-		return 0;
+	if (++masq_refcnt > 1)
+		goto out_unlock;
 
 	/* Register for device down reports */
 	ret = register_netdevice_notifier(&masq_dev_notifier);
@@ -166,22 +168,29 @@ int nf_nat_masquerade_ipv4_register_notifier(void)
 	if (ret)
 		goto err_unregister;
 
+	mutex_unlock(&masq_mutex);
 	return ret;
+
 err_unregister:
 	unregister_netdevice_notifier(&masq_dev_notifier);
 err_dec:
-	atomic_dec(&masquerade_notifier_refcount);
+	masq_refcnt--;
+out_unlock:
+	mutex_unlock(&masq_mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_register_notifier);
 
 void nf_nat_masquerade_ipv4_unregister_notifier(void)
 {
+	mutex_lock(&masq_mutex);
 	/* check if the notifier still has clients */
-	if (atomic_dec_return(&masquerade_notifier_refcount) > 0)
-		return;
+	if (--masq_refcnt > 0)
+		goto out_unlock;
 
 	unregister_netdevice_notifier(&masq_dev_notifier);
 	unregister_inetaddr_notifier(&masq_inet_notifier);
+out_unlock:
+	mutex_unlock(&masq_mutex);
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_unregister_notifier);
diff --git a/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
index 7afd1e63d2db..0ad0da5a2600 100644
--- a/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
+++ b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c
@@ -175,15 +175,17 @@ static struct notifier_block masq_inet6_notifier = {
 	.notifier_call	= masq_inet6_event,
 };
 
-static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);
+static int masq_refcnt;
+static DEFINE_MUTEX(masq_mutex);
 
 int nf_nat_masquerade_ipv6_register_notifier(void)
 {
-	int ret;
+	int ret = 0;
 
+	mutex_lock(&masq_mutex);
 	/* check if the notifier is already set */
-	if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
-		return 0;
+	if (++masq_refcnt > 1)
+		goto out_unlock;
 
 	ret = register_netdevice_notifier(&masq_dev_notifier);
 	if (ret)
@@ -193,22 +195,29 @@ int nf_nat_masquerade_ipv6_register_notifier(void)
 	if (ret)
 		goto err_unregister;
 
+	mutex_unlock(&masq_mutex);
 	return ret;
+
 err_unregister:
 	unregister_netdevice_notifier(&masq_dev_notifier);
 err_dec:
-	atomic_dec(&masquerade_notifier_refcount);
+	masq_refcnt--;
+out_unlock:
+	mutex_unlock(&masq_mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_register_notifier);
 
 void nf_nat_masquerade_ipv6_unregister_notifier(void)
 {
+	mutex_lock(&masq_mutex);
 	/* check if the notifier still has clients */
-	if (atomic_dec_return(&masquerade_notifier_refcount) > 0)
-		return;
+	if (--masq_refcnt > 0)
+		goto out_unlock;
 
 	unregister_inet6addr_notifier(&masq_inet6_notifier);
 	unregister_netdevice_notifier(&masq_dev_notifier);
+out_unlock:
+	mutex_unlock(&masq_mutex);
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_unregister_notifier);

From 53ca0f2fec39c80ccd19e6e3f30cc8daef174b70 Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Sun, 25 Nov 2018 18:47:13 +0900
Subject: [PATCH 15/16] netfilter: nf_conncount: remove wrong condition check
 routine

All lists that reach the tree_nodes_free() function have both zero
counter and true dead flag. The reason for this is that lists to be
release are selected by nf_conncount_gc_list() which already decrements
the list counter and sets on the dead flag. Therefore, this if statement
in tree_nodes_free() is unnecessary and wrong.

Fixes: 31568ec09ea0 ("netfilter: nf_conncount: fix list_del corruption in conn_free")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conncount.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index 8acae4a3e4c0..b6d0f6deea86 100644
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -323,11 +323,8 @@ static void tree_nodes_free(struct rb_root *root,
 	while (gc_count) {
 		rbconn = gc_nodes[--gc_count];
 		spin_lock(&rbconn->list.list_lock);
-		if (rbconn->list.count == 0 && rbconn->list.dead == false) {
-			rbconn->list.dead = true;
-			rb_erase(&rbconn->node, root);
-			call_rcu(&rbconn->rcu_head, __tree_nodes_free);
-		}
+		rb_erase(&rbconn->node, root);
+		call_rcu(&rbconn->rcu_head, __tree_nodes_free);
 		spin_unlock(&rbconn->list.list_lock);
 	}
 }

From ca08987885a147643817d02bf260bc4756ce8cd4 Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Wed, 28 Nov 2018 11:27:28 +0900
Subject: [PATCH 16/16] netfilter: nf_tables: deactivate expressions in rule
 replecement routine

There is no expression deactivation call from the rule replacement path,
hence, chain counter is not decremented. A few steps to reproduce the
problem:

   %nft add table ip filter
   %nft add chain ip filter c1
   %nft add chain ip filter c1
   %nft add rule ip filter c1 jump c2
   %nft replace rule ip filter c1 handle 3 accept
   %nft flush ruleset

<jump c2> expression means immediate NFT_JUMP to chain c2.
Reference count of chain c2 is increased when the rule is added.

When rule is deleted or replaced, the reference counter of c2 should be
decreased via nft_rule_expr_deactivate() which calls
nft_immediate_deactivate().

Splat looks like:
[  214.396453] WARNING: CPU: 1 PID: 21 at net/netfilter/nf_tables_api.c:1432 nf_tables_chain_destroy.isra.38+0x2f9/0x3a0 [nf_tables]
[  214.398983] Modules linked in: nf_tables nfnetlink
[  214.398983] CPU: 1 PID: 21 Comm: kworker/1:1 Not tainted 4.20.0-rc2+ #44
[  214.398983] Workqueue: events nf_tables_trans_destroy_work [nf_tables]
[  214.398983] RIP: 0010:nf_tables_chain_destroy.isra.38+0x2f9/0x3a0 [nf_tables]
[  214.398983] Code: 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 8e 00 00 00 48 8b 7b 58 e8 e1 2c 4e c6 48 89 df e8 d9 2c 4e c6 eb 9a <0f> 0b eb 96 0f 0b e9 7e fe ff ff e8 a7 7e 4e c6 e9 a4 fe ff ff e8
[  214.398983] RSP: 0018:ffff8881152874e8 EFLAGS: 00010202
[  214.398983] RAX: 0000000000000001 RBX: ffff88810ef9fc28 RCX: ffff8881152876f0
[  214.398983] RDX: dffffc0000000000 RSI: 1ffff11022a50ede RDI: ffff88810ef9fc78
[  214.398983] RBP: 1ffff11022a50e9d R08: 0000000080000000 R09: 0000000000000000
[  214.398983] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff11022a50eba
[  214.398983] R13: ffff888114446e08 R14: ffff8881152876f0 R15: ffffed1022a50ed6
[  214.398983] FS:  0000000000000000(0000) GS:ffff888116400000(0000) knlGS:0000000000000000
[  214.398983] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  214.398983] CR2: 00007fab9bb5f868 CR3: 000000012aa16000 CR4: 00000000001006e0
[  214.398983] Call Trace:
[  214.398983]  ? nf_tables_table_destroy.isra.37+0x100/0x100 [nf_tables]
[  214.398983]  ? __kasan_slab_free+0x145/0x180
[  214.398983]  ? nf_tables_trans_destroy_work+0x439/0x830 [nf_tables]
[  214.398983]  ? kfree+0xdb/0x280
[  214.398983]  nf_tables_trans_destroy_work+0x5f5/0x830 [nf_tables]
[ ... ]

Fixes: bb7b40aecbf7 ("netfilter: nf_tables: bogus EBUSY in chain deletions")
Reported by: Christoph Anton Mitterer <calestyo@scientia.net>
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914505
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201791
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ddeaa1990e1e..2e61aab6ed73 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2667,21 +2667,14 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
 	}
 
 	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
-		if (!nft_is_active_next(net, old_rule)) {
-			err = -ENOENT;
-			goto err2;
-		}
-		trans = nft_trans_rule_add(&ctx, NFT_MSG_DELRULE,
-					   old_rule);
+		trans = nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule);
 		if (trans == NULL) {
 			err = -ENOMEM;
 			goto err2;
 		}
-		nft_deactivate_next(net, old_rule);
-		chain->use--;
-
-		if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) {
-			err = -ENOMEM;
+		err = nft_delrule(&ctx, old_rule);
+		if (err < 0) {
+			nft_trans_destroy(trans);
 			goto err2;
 		}