[PATCH net 0/7] Netfilter fixes for net

[PATCH net 0/7] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi,

The following patchset contains Netfilter fixes for net:

1) Fix bogus compilter warning in nfnetlink_queue, from Florian Westphal.

2) Don't run conntrack on vrf with !dflt qdisc, from Nicolas Dichtel.

3) Fix nft_pipapo bucket load in AVX2 lookup routine for six 8-bit
   groups, from Stefano Brivio.

4) Break rule evaluation on malformed TCP options.

5) Use socat instead of nc in selftests/netfilter/nft_zones_many.sh,
   also from Florian

6) Fix KCSAN data-race in conntrack timeout updates, from Eric Dumazet.

Please, pull these changes from:

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

Thanks.

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

The following changes since commit 34d8778a943761121f391b7921f79a7adbe1feaf:

  MAINTAINERS: s390/net: add Alexandra and Wenjia as maintainer (2021-11-30 12:20:07 +0000)

are available in the Git repository at:

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

for you to fetch changes up to 802a7dc5cf1bef06f7b290ce76d478138408d6b1:

  netfilter: conntrack: annotate data-races around ct->timeout (2021-12-08 01:29:15 +0100)

----------------------------------------------------------------
Eric Dumazet (1):
      netfilter: conntrack: annotate data-races around ct->timeout

Florian Westphal (2):
      netfilter: nfnetlink_queue: silence bogus compiler warning
      selftests: netfilter: switch zone stress to socat

Nicolas Dichtel (1):
      vrf: don't run conntrack on vrf with !dflt qdisc

Pablo Neira Ayuso (1):
      netfilter: nft_exthdr: break evaluation if setting TCP option fails

Stefano Brivio (2):
      nft_set_pipapo: Fix bucket load in AVX2 lookup routine for six 8-bit groups
      selftests: netfilter: Add correctness test for mac,net set type

 drivers/net/vrf.c                                  |  8 +++---
 include/net/netfilter/nf_conntrack.h               |  6 ++---
 net/netfilter/nf_conntrack_core.c                  |  6 ++---
 net/netfilter/nf_conntrack_netlink.c               |  2 +-
 net/netfilter/nf_flow_table_core.c                 |  4 +--
 net/netfilter/nfnetlink_queue.c                    |  2 +-
 net/netfilter/nft_exthdr.c                         | 11 +++++---
 net/netfilter/nft_set_pipapo_avx2.c                |  2 +-
 tools/testing/selftests/netfilter/conntrack_vrf.sh | 30 +++++++++++++++++++---
 .../selftests/netfilter/nft_concat_range.sh        | 24 ++++++++++++++---
 .../testing/selftests/netfilter/nft_zones_many.sh  | 19 +++++++++-----
 11 files changed, 82 insertions(+), 32 deletions(-)

[PATCH net 1/7] netfilter: nfnetlink_queue: silence bogus compiler warning

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

net/netfilter/nfnetlink_queue.c:601:36: warning: variable 'ctinfo' is
uninitialized when used here [-Wuninitialized]
   if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)

ctinfo is only uninitialized if ct == NULL.  Init it to 0 to silence this.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nfnetlink_queue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 4acc4b8e9fe5..5837e8efc9c2 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -387,7 +387,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	struct net_device *indev;
 	struct net_device *outdev;
 	struct nf_conn *ct = NULL;
-	enum ip_conntrack_info ctinfo;
+	enum ip_conntrack_info ctinfo = 0;
 	struct nfnl_ct_hook *nfnl_ct;
 	bool csum_verify;
 	char *secdata = NULL;
-- 
2.30.2

[PATCH net 2/7] vrf: don't run conntrack on vrf with !dflt qdisc

[Pablo Neira Ayuso]

From: Nicolas Dichtel <nicolas.dichtel@6wind.com>

After the below patch, the conntrack attached to skb is set to "notrack" in
the context of vrf device, for locally generated packets.
But this is true only when the default qdisc is set to the vrf device. When
changing the qdisc, notrack is not set anymore.
In fact, there is a shortcut in the vrf driver, when the default qdisc is
set, see commit dcdd43c41e60 ("net: vrf: performance improvements for
IPv4") for more details.

This patch ensures that the behavior is always the same, whatever the qdisc
is.

To demonstrate the difference, a new test is added in conntrack_vrf.sh.

Fixes: 8c9c296adfae ("vrf: run conntrack only in context of lower/physdev for locally generated packets")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Florian Westphal <fw@strlen.de>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 drivers/net/vrf.c                             |  8 ++---
 .../selftests/netfilter/conntrack_vrf.sh      | 30 ++++++++++++++++---
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index ccf677015d5b..38c2f0dbe795 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -768,8 +768,6 @@ static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
 
 	skb->dev = vrf_dev;
 
-	vrf_nf_set_untracked(skb);
-
 	err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
 		      skb, NULL, vrf_dev, vrf_ip6_out_direct_finish);
 
@@ -790,6 +788,8 @@ static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
 	if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
 		return skb;
 
+	vrf_nf_set_untracked(skb);
+
 	if (qdisc_tx_is_default(vrf_dev) ||
 	    IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
 		return vrf_ip6_out_direct(vrf_dev, sk, skb);
@@ -998,8 +998,6 @@ static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
 
 	skb->dev = vrf_dev;
 
-	vrf_nf_set_untracked(skb);
-
 	err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
 		      skb, NULL, vrf_dev, vrf_ip_out_direct_finish);
 
@@ -1021,6 +1019,8 @@ static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
 	    ipv4_is_lbcast(ip_hdr(skb)->daddr))
 		return skb;
 
+	vrf_nf_set_untracked(skb);
+
 	if (qdisc_tx_is_default(vrf_dev) ||
 	    IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
 		return vrf_ip_out_direct(vrf_dev, sk, skb);
diff --git a/tools/testing/selftests/netfilter/conntrack_vrf.sh b/tools/testing/selftests/netfilter/conntrack_vrf.sh
index 91f3ef0f1192..8b5ea9234588 100755
--- a/tools/testing/selftests/netfilter/conntrack_vrf.sh
+++ b/tools/testing/selftests/netfilter/conntrack_vrf.sh
@@ -150,11 +150,27 @@ EOF
 # oifname is the vrf device.
 test_masquerade_vrf()
 {
+	local qdisc=$1
+
+	if [ "$qdisc" != "default" ]; then
+		tc -net $ns0 qdisc add dev tvrf root $qdisc
+	fi
+
 	ip netns exec $ns0 conntrack -F 2>/dev/null
 
 ip netns exec $ns0 nft -f - <<EOF
 flush ruleset
 table ip nat {
+	chain rawout {
+		type filter hook output priority raw;
+
+		oif tvrf ct state untracked counter
+	}
+	chain postrouting2 {
+		type filter hook postrouting priority mangle;
+
+		oif tvrf ct state untracked counter
+	}
 	chain postrouting {
 		type nat hook postrouting priority 0;
 		# NB: masquerade should always be combined with 'oif(name) bla',
@@ -171,13 +187,18 @@ EOF
 	fi
 
 	# must also check that nat table was evaluated on second (lower device) iteration.
-	ip netns exec $ns0 nft list table ip nat |grep -q 'counter packets 2'
+	ip netns exec $ns0 nft list table ip nat |grep -q 'counter packets 2' &&
+	ip netns exec $ns0 nft list table ip nat |grep -q 'untracked counter packets [1-9]'
 	if [ $? -eq 0 ]; then
-		echo "PASS: iperf3 connect with masquerade + sport rewrite on vrf device"
+		echo "PASS: iperf3 connect with masquerade + sport rewrite on vrf device ($qdisc qdisc)"
 	else
-		echo "FAIL: vrf masq rule has unexpected counter value"
+		echo "FAIL: vrf rules have unexpected counter value"
 		ret=1
 	fi
+
+	if [ "$qdisc" != "default" ]; then
+		tc -net $ns0 qdisc del dev tvrf root
+	fi
 }
 
 # add masq rule that gets evaluated w. outif set to veth device.
@@ -213,7 +234,8 @@ EOF
 }
 
 test_ct_zone_in
-test_masquerade_vrf
+test_masquerade_vrf "default"
+test_masquerade_vrf "pfifo"
 test_masquerade_veth
 
 exit $ret
-- 
2.30.2

[PATCH net 3/7] nft_set_pipapo: Fix bucket load in AVX2 lookup routine for six 8-bit groups

[Pablo Neira Ayuso]

From: Stefano Brivio <sbrivio@redhat.com>

The sixth byte of packet data has to be looked up in the sixth group,
not in the seventh one, even if we load the bucket data into ymm6
(and not ymm5, for convenience of tracking stalls).

Without this fix, matching on a MAC address as first field of a set,
if 8-bit groups are selected (due to a small set size) would fail,
that is, the given MAC address would never match.

Reported-by: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com>
Cc: <stable@vger.kernel.org> # 5.6.x
Fixes: 7400b063969b ("nft_set_pipapo: Introduce AVX2-based lookup implementation")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Tested-By: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo_avx2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nft_set_pipapo_avx2.c b/net/netfilter/nft_set_pipapo_avx2.c
index e517663e0cd1..6f4116e72958 100644
--- a/net/netfilter/nft_set_pipapo_avx2.c
+++ b/net/netfilter/nft_set_pipapo_avx2.c
@@ -886,7 +886,7 @@ static int nft_pipapo_avx2_lookup_8b_6(unsigned long *map, unsigned long *fill,
 			NFT_PIPAPO_AVX2_BUCKET_LOAD8(4,  lt, 4, pkt[4], bsize);
 
 			NFT_PIPAPO_AVX2_AND(5, 0, 1);
-			NFT_PIPAPO_AVX2_BUCKET_LOAD8(6,  lt, 6, pkt[5], bsize);
+			NFT_PIPAPO_AVX2_BUCKET_LOAD8(6,  lt, 5, pkt[5], bsize);
 			NFT_PIPAPO_AVX2_AND(7, 2, 3);
 
 			/* Stall */
-- 
2.30.2

[PATCH net 4/7] selftests: netfilter: Add correctness test for mac,net set type

[Pablo Neira Ayuso]

From: Stefano Brivio <sbrivio@redhat.com>

The existing net,mac test didn't cover the issue recently reported
by Nikita Yushchenko, where MAC addresses wouldn't match if given
as first field of a concatenated set with AVX2 and 8-bit groups,
because there's a different code path covering the lookup of six
8-bit groups (MAC addresses) if that's the first field.

Add a similar mac,net test, with MAC address and IPv4 address
swapped in the set specification.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 .../selftests/netfilter/nft_concat_range.sh   | 24 ++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/netfilter/nft_concat_range.sh b/tools/testing/selftests/netfilter/nft_concat_range.sh
index 5a4938d6dcf2..ed61f6cab60f 100755
--- a/tools/testing/selftests/netfilter/nft_concat_range.sh
+++ b/tools/testing/selftests/netfilter/nft_concat_range.sh
@@ -23,8 +23,8 @@ TESTS="reported_issues correctness concurrency timeout"
 
 # Set types, defined by TYPE_ variables below
 TYPES="net_port port_net net6_port port_proto net6_port_mac net6_port_mac_proto
-       net_port_net net_mac net_mac_icmp net6_mac_icmp net6_port_net6_port
-       net_port_mac_proto_net"
+       net_port_net net_mac mac_net net_mac_icmp net6_mac_icmp
+       net6_port_net6_port net_port_mac_proto_net"
 
 # Reported bugs, also described by TYPE_ variables below
 BUGS="flush_remove_add"
@@ -277,6 +277,23 @@ perf_entries	1000
 perf_proto	ipv4
 "
 
+TYPE_mac_net="
+display		mac,net
+type_spec	ether_addr . ipv4_addr
+chain_spec	ether saddr . ip saddr
+dst		 
+src		mac addr4
+start		1
+count		5
+src_delta	2000
+tools		sendip nc bash
+proto		udp
+
+race_repeat	0
+
+perf_duration	0
+"
+
 TYPE_net_mac_icmp="
 display		net,mac - ICMP
 type_spec	ipv4_addr . ether_addr
@@ -984,7 +1001,8 @@ format() {
 		fi
 	done
 	for f in ${src}; do
-		__expr="${__expr} . "
+		[ "${__expr}" != "{ " ] && __expr="${__expr} . "
+
 		__start="$(eval format_"${f}" "${srcstart}")"
 		__end="$(eval format_"${f}" "${srcend}")"
 
-- 
2.30.2

[PATCH net 5/7] netfilter: nft_exthdr: break evaluation if setting TCP option fails

[Pablo Neira Ayuso]

Break rule evaluation on malformed TCP options.

Fixes: 99d1712bc41c ("netfilter: exthdr: tcp option set support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_exthdr.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c
index af4ee874a067..dbe1f2e7dd9e 100644
--- a/net/netfilter/nft_exthdr.c
+++ b/net/netfilter/nft_exthdr.c
@@ -236,7 +236,7 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr,
 
 	tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
 	if (!tcph)
-		return;
+		goto err;
 
 	opt = (u8 *)tcph;
 	for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) {
@@ -251,16 +251,16 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr,
 			continue;
 
 		if (i + optl > tcphdr_len || priv->len + priv->offset > optl)
-			return;
+			goto err;
 
 		if (skb_ensure_writable(pkt->skb,
 					nft_thoff(pkt) + i + priv->len))
-			return;
+			goto err;
 
 		tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff,
 					      &tcphdr_len);
 		if (!tcph)
-			return;
+			goto err;
 
 		offset = i + priv->offset;
 
@@ -303,6 +303,9 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr,
 
 		return;
 	}
+	return;
+err:
+	regs->verdict.code = NFT_BREAK;
 }
 
 static void nft_exthdr_sctp_eval(const struct nft_expr *expr,
-- 
2.30.2

[PATCH net 6/7] selftests: netfilter: switch zone stress to socat

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

centos9 has nmap-ncat which doesn't like the '-q' option, use socat.
While at it, mark test skipped if needed tools are missing.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 .../selftests/netfilter/nft_zones_many.sh     | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/netfilter/nft_zones_many.sh b/tools/testing/selftests/netfilter/nft_zones_many.sh
index ac646376eb01..04633119b29a 100755
--- a/tools/testing/selftests/netfilter/nft_zones_many.sh
+++ b/tools/testing/selftests/netfilter/nft_zones_many.sh
@@ -18,11 +18,17 @@ cleanup()
 	ip netns del $ns
 }
 
-ip netns add $ns
-if [ $? -ne 0 ];then
-	echo "SKIP: Could not create net namespace $gw"
-	exit $ksft_skip
-fi
+checktool (){
+	if ! $1 > /dev/null 2>&1; then
+		echo "SKIP: Could not $2"
+		exit $ksft_skip
+	fi
+}
+
+checktool "nft --version" "run test without nft tool"
+checktool "ip -Version" "run test without ip tool"
+checktool "socat -V" "run test without socat tool"
+checktool "ip netns add $ns" "create net namespace"
 
 trap cleanup EXIT
 
@@ -71,7 +77,8 @@ EOF
 		local start=$(date +%s%3N)
 		i=$((i + 10000))
 		j=$((j + 1))
-		dd if=/dev/zero of=/dev/stdout bs=8k count=10000 2>/dev/null | ip netns exec "$ns" nc -w 1 -q 1 -u -p 12345 127.0.0.1 12345 > /dev/null
+		# nft rule in output places each packet in a different zone.
+		dd if=/dev/zero of=/dev/stdout bs=8k count=10000 2>/dev/null | ip netns exec "$ns" socat STDIN UDP:127.0.0.1:12345,sourceport=12345
 		if [ $? -ne 0 ] ;then
 			ret=1
 			break
-- 
2.30.2

[PATCH net 7/7] netfilter: conntrack: annotate data-races around ct->timeout

[Pablo Neira Ayuso]

From: Eric Dumazet <edumazet@google.com>

(struct nf_conn)->timeout can be read/written locklessly,
add READ_ONCE()/WRITE_ONCE() to prevent load/store tearing.

BUG: KCSAN: data-race in __nf_conntrack_alloc / __nf_conntrack_find_get

write to 0xffff888132e78c08 of 4 bytes by task 6029 on cpu 0:
 __nf_conntrack_alloc+0x158/0x280 net/netfilter/nf_conntrack_core.c:1563
 init_conntrack+0x1da/0xb30 net/netfilter/nf_conntrack_core.c:1635
 resolve_normal_ct+0x502/0x610 net/netfilter/nf_conntrack_core.c:1746
 nf_conntrack_in+0x1c5/0x88f net/netfilter/nf_conntrack_core.c:1901
 ipv6_conntrack_local+0x19/0x20 net/netfilter/nf_conntrack_proto.c:414
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_slow+0x72/0x170 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:262 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0xa3a/0xa60 net/ipv6/ip6_output.c:324
 inet6_csk_xmit+0x1a2/0x1e0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x132a/0x1840 net/ipv4/tcp_output.c:1402
 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline]
 tcp_write_xmit+0x1450/0x4460 net/ipv4/tcp_output.c:2680
 __tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2864
 tcp_push_pending_frames include/net/tcp.h:1897 [inline]
 tcp_data_snd_check+0x62/0x2e0 net/ipv4/tcp_input.c:5452
 tcp_rcv_established+0x880/0x10e0 net/ipv4/tcp_input.c:5947
 tcp_v6_do_rcv+0x36e/0xa50 net/ipv6/tcp_ipv6.c:1521
 sk_backlog_rcv include/net/sock.h:1030 [inline]
 __release_sock+0xf2/0x270 net/core/sock.c:2768
 release_sock+0x40/0x110 net/core/sock.c:3300
 sk_stream_wait_memory+0x435/0x700 net/core/stream.c:145
 tcp_sendmsg_locked+0xb85/0x25a0 net/ipv4/tcp.c:1402
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1440
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 __sys_sendto+0x21e/0x2c0 net/socket.c:2036
 __do_sys_sendto net/socket.c:2048 [inline]
 __se_sys_sendto net/socket.c:2044 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2044
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888132e78c08 of 4 bytes by task 17446 on cpu 1:
 nf_ct_is_expired include/net/netfilter/nf_conntrack.h:286 [inline]
 ____nf_conntrack_find net/netfilter/nf_conntrack_core.c:776 [inline]
 __nf_conntrack_find_get+0x1c7/0xac0 net/netfilter/nf_conntrack_core.c:807
 resolve_normal_ct+0x273/0x610 net/netfilter/nf_conntrack_core.c:1734
 nf_conntrack_in+0x1c5/0x88f net/netfilter/nf_conntrack_core.c:1901
 ipv6_conntrack_local+0x19/0x20 net/netfilter/nf_conntrack_proto.c:414
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_slow+0x72/0x170 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:262 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0xa3a/0xa60 net/ipv6/ip6_output.c:324
 inet6_csk_xmit+0x1a2/0x1e0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x132a/0x1840 net/ipv4/tcp_output.c:1402
 __tcp_send_ack+0x1fd/0x300 net/ipv4/tcp_output.c:3956
 tcp_send_ack+0x23/0x30 net/ipv4/tcp_output.c:3962
 __tcp_ack_snd_check+0x2d8/0x510 net/ipv4/tcp_input.c:5478
 tcp_ack_snd_check net/ipv4/tcp_input.c:5523 [inline]
 tcp_rcv_established+0x8c2/0x10e0 net/ipv4/tcp_input.c:5948
 tcp_v6_do_rcv+0x36e/0xa50 net/ipv6/tcp_ipv6.c:1521
 sk_backlog_rcv include/net/sock.h:1030 [inline]
 __release_sock+0xf2/0x270 net/core/sock.c:2768
 release_sock+0x40/0x110 net/core/sock.c:3300
 tcp_sendpage+0x94/0xb0 net/ipv4/tcp.c:1114
 inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833
 rds_tcp_xmit+0x376/0x5f0 net/rds/tcp_send.c:118
 rds_send_xmit+0xbed/0x1500 net/rds/send.c:367
 rds_send_worker+0x43/0x200 net/rds/threads.c:200
 process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
 worker_thread+0x616/0xa70 kernel/workqueue.c:2445
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

value changed: 0x00027cc2 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17446 Comm: kworker/u4:5 Tainted: G        W         5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krdsd rds_send_worker

Note: I chose an arbitrary commit for the Fixes: tag,
because I do not think we need to backport this fix to very old kernels.

Fixes: e37542ba111f ("netfilter: conntrack: avoid possible false sharing")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/netfilter/nf_conntrack.h | 6 +++---
 net/netfilter/nf_conntrack_core.c    | 6 +++---
 net/netfilter/nf_conntrack_netlink.c | 2 +-
 net/netfilter/nf_flow_table_core.c   | 4 ++--
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index cc663c68ddc4..d24b0a34c8f0 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -276,14 +276,14 @@ static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
 /* jiffies until ct expires, 0 if already expired */
 static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
 {
-	s32 timeout = ct->timeout - nfct_time_stamp;
+	s32 timeout = READ_ONCE(ct->timeout) - nfct_time_stamp;
 
 	return timeout > 0 ? timeout : 0;
 }
 
 static inline bool nf_ct_is_expired(const struct nf_conn *ct)
 {
-	return (__s32)(ct->timeout - nfct_time_stamp) <= 0;
+	return (__s32)(READ_ONCE(ct->timeout) - nfct_time_stamp) <= 0;
 }
 
 /* use after obtaining a reference count */
@@ -302,7 +302,7 @@ static inline bool nf_ct_should_gc(const struct nf_conn *ct)
 static inline void nf_ct_offload_timeout(struct nf_conn *ct)
 {
 	if (nf_ct_expires(ct) < NF_CT_DAY / 2)
-		ct->timeout = nfct_time_stamp + NF_CT_DAY;
+		WRITE_ONCE(ct->timeout, nfct_time_stamp + NF_CT_DAY);
 }
 
 struct kernel_param;
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 770a63103c7a..4712a90a1820 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -684,7 +684,7 @@ bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 
 	tstamp = nf_conn_tstamp_find(ct);
 	if (tstamp) {
-		s32 timeout = ct->timeout - nfct_time_stamp;
+		s32 timeout = READ_ONCE(ct->timeout) - nfct_time_stamp;
 
 		tstamp->stop = ktime_get_real_ns();
 		if (timeout < 0)
@@ -1036,7 +1036,7 @@ static int nf_ct_resolve_clash_harder(struct sk_buff *skb, u32 repl_idx)
 	}
 
 	/* We want the clashing entry to go away real soon: 1 second timeout. */
-	loser_ct->timeout = nfct_time_stamp + HZ;
+	WRITE_ONCE(loser_ct->timeout, nfct_time_stamp + HZ);
 
 	/* IPS_NAT_CLASH removes the entry automatically on the first
 	 * reply.  Also prevents UDP tracker from moving the entry to
@@ -1560,7 +1560,7 @@ __nf_conntrack_alloc(struct net *net,
 	/* save hash for reusing when confirming */
 	*(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
 	ct->status = 0;
-	ct->timeout = 0;
+	WRITE_ONCE(ct->timeout, 0);
 	write_pnet(&ct->ct_net, net);
 	memset(&ct->__nfct_init_offset, 0,
 	       offsetof(struct nf_conn, proto) -
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index c7708bde057c..81d03acf68d4 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1998,7 +1998,7 @@ static int ctnetlink_change_timeout(struct nf_conn *ct,
 
 	if (timeout > INT_MAX)
 		timeout = INT_MAX;
-	ct->timeout = nfct_time_stamp + (u32)timeout;
+	WRITE_ONCE(ct->timeout, nfct_time_stamp + (u32)timeout);
 
 	if (test_bit(IPS_DYING_BIT, &ct->status))
 		return -ETIME;
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 87a7388b6c89..ed37bb9b4e58 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -201,8 +201,8 @@ static void flow_offload_fixup_ct_timeout(struct nf_conn *ct)
 	if (timeout < 0)
 		timeout = 0;
 
-	if (nf_flow_timeout_delta(ct->timeout) > (__s32)timeout)
-		ct->timeout = nfct_time_stamp + timeout;
+	if (nf_flow_timeout_delta(READ_ONCE(ct->timeout)) > (__s32)timeout)
+		WRITE_ONCE(ct->timeout, nfct_time_stamp + timeout);
 }
 
 static void flow_offload_fixup_ct_state(struct nf_conn *ct)
-- 
2.30.2

Re: [PATCH net 1/7] netfilter: nfnetlink_queue: silence bogus compiler warning

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (master)
by Pablo Neira Ayuso <pablo@netfilter.org>:

On Thu,  9 Dec 2021 01:08:41 +0100 you wrote:
> From: Florian Westphal <fw@strlen.de>
> 
> net/netfilter/nfnetlink_queue.c:601:36: warning: variable 'ctinfo' is
> uninitialized when used here [-Wuninitialized]
>    if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
> 
> ctinfo is only uninitialized if ct == NULL.  Init it to 0 to silence this.
> 
> [...]

Here is the summary with links:
  - [net,1/7] netfilter: nfnetlink_queue: silence bogus compiler warning
    https://git.kernel.org/netdev/net/c/b43c2793f5e9
  - [net,2/7] vrf: don't run conntrack on vrf with !dflt qdisc
    https://git.kernel.org/netdev/net/c/d43b75fbc23f
  - [net,3/7] nft_set_pipapo: Fix bucket load in AVX2 lookup routine for six 8-bit groups
    https://git.kernel.org/netdev/net/c/b7e945e228d7
  - [net,4/7] selftests: netfilter: Add correctness test for mac,net set type
    https://git.kernel.org/netdev/net/c/0de53b0ffb5b
  - [net,5/7] netfilter: nft_exthdr: break evaluation if setting TCP option fails
    https://git.kernel.org/netdev/net/c/962e5a403587
  - [net,6/7] selftests: netfilter: switch zone stress to socat
    https://git.kernel.org/netdev/net/c/d46cea0e6933
  - [net,7/7] netfilter: conntrack: annotate data-races around ct->timeout
    https://git.kernel.org/netdev/net/c/802a7dc5cf1b

You are awesome, thank you!
-- 
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