linux.git/net/ipv4, branch v4.19-rc4

erspan: fix error handling for erspan tunnel

2018-09-12T06:50:54+00:00

When processing icmp unreachable message for erspan tunnel, tunnel id
should be erspan_net_id instead of ipgre_net_id.

Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
Cc: William Tu 
Signed-off-by: Haishuang Yan 
Acked-by: William Tu 
Signed-off-by: David S. Miller

erspan: return PACKET_REJECT when the appropriate tunnel is not found

2018-09-12T06:50:53+00:00

If erspan tunnel hasn't been established, we'd better send icmp port
unreachable message after receive erspan packets.

Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
Cc: William Tu 
Signed-off-by: Haishuang Yan 
Acked-by: William Tu 
Signed-off-by: David S. Miller

tcp: rate limit synflood warnings further

2018-09-12T06:34:20+00:00

Convert pr_info to net_info_ratelimited to limit the total number of
synflood warnings.

Commit 946cedccbd73 ("tcp: Change possible SYN flooding messages")
rate limits synflood warnings to one per listener.

Workloads that open many listener sockets can still see a high rate of
log messages. Syzkaller is one frequent example.

Signed-off-by: Willem de Bruijn 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2018-09-12T04:17:30+00:00

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter fixes for you net tree:

1) Remove duplicated include at the end of UDP conntrack, from Yue Haibing.

2) Restore conntrack dependency on xt_cluster, from Martin Willi.

3) Fix splat with GSO skbs from the checksum target, from Florian Westphal.

4) Rework ct timeout support, the template strategy to attach custom timeouts
   is not correct since it will not work in conjunction with conntrack zones
   and we have a possible free after use when removing the rule due to missing
   refcounting. To fix these problems, do not use conntrack template at all
   and set custom timeout on the already valid conntrack object. This
   fix comes with a preparation patch to simplify timeout adjustment by
   initializating the first position of the timeout array for all of the
   existing trackers. Patchset from Florian Westphal.

5) Fix missing dependency on from IPv4 chain NAT type, from Florian.

6) Release chain reference counter from the flush path, from Taehee Yoo.

7) After flushing an iptables ruleset, conntrack hooks are unregistered
   and entries are left stale to be cleaned up by the timeout garbage
   collector. No TCP tracking is done on established flows by this time.
   If ruleset is reloaded, then hooks are registered again and TCP
   tracking is restored, which considers packets to be invalid. Clear
   window tracking to exercise TCP flow pickup from the middle given that
   history is lost for us. Again from Florian.

8) Fix crash from netlink interface with CONFIG_NF_CONNTRACK_TIMEOUT=y
   and CONFIG_NF_CT_NETLINK_TIMEOUT=n.

9) Broken CT target due to returning incorrect type from
   ctnl_timeout_find_get().

10) Solve conntrack clash on NF_REPEAT verdicts too, from Michal Vaner.

11) Missing conversion of hashlimit sysctl interface to new API, from
    Cong Wang.
====================

Signed-off-by: David S. Miller

ip: frags: fix crash in ip_do_fragment()

2018-09-09T21:50:56+00:00

A kernel crash occurrs when defragmented packet is fragmented
in ip_do_fragment().
In defragment routine, skb_orphan() is called and
skb->ip_defrag_offset is set. but skb->sk and
skb->ip_defrag_offset are same union member. so that
frag->sk is not NULL.
Hence crash occurrs in skb->sk check routine in ip_do_fragment() when
defragmented packet is fragmented.

test commands:
   %iptables -t nat -I POSTROUTING -j MASQUERADE
   %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000

splat looks like:
[  261.069429] kernel BUG at net/ipv4/ip_output.c:636!
[  261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3
[  261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600
[  261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c
[  261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202
[  261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004
[  261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8
[  261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395
[  261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4
[  261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000
[  261.174169] FS:  00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000
[  261.183012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0
[  261.198158] Call Trace:
[  261.199018]  ? dst_output+0x180/0x180
[  261.205011]  ? save_trace+0x300/0x300
[  261.209018]  ? ip_copy_metadata+0xb00/0xb00
[  261.213034]  ? sched_clock_local+0xd4/0x140
[  261.218158]  ? kill_l4proto+0x120/0x120 [nf_conntrack]
[  261.223014]  ? rt_cpu_seq_stop+0x10/0x10
[  261.227014]  ? find_held_lock+0x39/0x1c0
[  261.233008]  ip_finish_output+0x51d/0xb50
[  261.237006]  ? ip_fragment.constprop.56+0x220/0x220
[  261.243011]  ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack]
[  261.250152]  ? rcu_is_watching+0x77/0x120
[  261.255010]  ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4]
[  261.261033]  ? nf_hook_slow+0xb1/0x160
[  261.265007]  ip_output+0x1c7/0x710
[  261.269005]  ? ip_mc_output+0x13f0/0x13f0
[  261.273002]  ? __local_bh_enable_ip+0xe9/0x1b0
[  261.278152]  ? ip_fragment.constprop.56+0x220/0x220
[  261.282996]  ? nf_hook_slow+0xb1/0x160
[  261.287007]  raw_sendmsg+0x21f9/0x4420
[  261.291008]  ? dst_output+0x180/0x180
[  261.297003]  ? sched_clock_cpu+0x126/0x170
[  261.301003]  ? find_held_lock+0x39/0x1c0
[  261.306155]  ? stop_critical_timings+0x420/0x420
[  261.311004]  ? check_flags.part.36+0x450/0x450
[  261.315005]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.320995]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.326142]  ? cyc2ns_read_end+0x10/0x10
[  261.330139]  ? raw_bind+0x280/0x280
[  261.334138]  ? sched_clock_cpu+0x126/0x170
[  261.338995]  ? check_flags.part.36+0x450/0x450
[  261.342991]  ? __lock_acquire+0x4500/0x4500
[  261.348994]  ? inet_sendmsg+0x11c/0x500
[  261.352989]  ? dst_output+0x180/0x180
[  261.357012]  inet_sendmsg+0x11c/0x500
[ ... ]

v2:
 - clear skb->sk at reassembly routine.(Eric Dumarzet)

Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.")
Suggested-by: Eric Dumazet 
Signed-off-by: Taehee Yoo 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

tcp: really ignore MSG_ZEROCOPY if no SO_ZEROCOPY

2018-09-08T06:11:06+00:00

According to the documentation in msg_zerocopy.rst, the SO_ZEROCOPY
flag was introduced because send(2) ignores unknown message flags and
any legacy application which was accidentally passing the equivalent of
MSG_ZEROCOPY earlier should not see any new behaviour.

Before commit f214f915e7db ("tcp: enable MSG_ZEROCOPY"), a send(2) call
which passed the equivalent of MSG_ZEROCOPY without setting SO_ZEROCOPY
would succeed.  However, after that commit, it fails with -ENOBUFS.  So
it appears that the SO_ZEROCOPY flag fails to fulfill its intended
purpose.  Fix it.

Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Vincent Whitchurch 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller

igmp: fix incorrect unsolicit report count after link down and up

2018-09-02T20:39:37+00:00

After link down and up, i.e. when call ip_mc_up(), we doesn't init
im->unsolicit_count. So after igmp_timer_expire(), we will not start
timer again and only send one unsolicit report at last.

Fix it by initializing im->unsolicit_count in igmp_group_added(), so
we can respect igmp robustness value.

Fixes: 24803f38a5c0b ("igmp: do not remove igmp souce list info when set link down")
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller

igmp: fix incorrect unsolicit report count when join group

2018-09-02T20:39:37+00:00

We should not start timer if im->unsolicit_count equal to 0 after decrease.
Or we will send one more unsolicit report message. i.e. 3 instead of 2 by
default.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller

tcp: do not restart timewait timer on rst reception

2018-09-01T06:10:35+00:00

RFC 1337 says:
 ''Ignore RST segments in TIME-WAIT state.
   If the 2 minute MSL is enforced, this fix avoids all three hazards.''

So with net.ipv4.tcp_rfc1337=1, expected behaviour is to have TIME-WAIT sk
expire rather than removing it instantly when a reset is received.

However, Linux will also re-start the TIME-WAIT timer.

This causes connect to fail when tying to re-use ports or very long
delays (until syn retry interval exceeds MSL).

packetdrill test case:
// Demonstrate bogus rearming of TIME-WAIT timer in rfc1337 mode.
`sysctl net.ipv4.tcp_rfc1337=1`

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0

0.100 < S 0:0(0) win 29200 
0.100 > S. 0:0(0) ack 1 
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4

// Receive first segment
0.310 < P. 1:1001(1000) ack 1 win 46

// Send one ACK
0.310 > . 1:1(0) ack 1001

// read 1000 byte
0.310 read(4, ..., 1000) = 1000

// Application writes 100 bytes
0.350 write(4, ..., 100) = 100
0.350 > P. 1:101(100) ack 1001

// ACK
0.500 < . 1001:1001(0) ack 101 win 257

// close the connection
0.600 close(4) = 0
0.600 > F. 101:101(0) ack 1001 win 244

// Our side is in FIN_WAIT_1 & waits for ack to fin
0.7 < . 1001:1001(0) ack 102 win 244

// Our side is in FIN_WAIT_2 with no outstanding data.
0.8 < F. 1001:1001(0) ack 102 win 244
0.8 > . 102:102(0) ack 1002 win 244

// Our side is now in TIME_WAIT state, send ack for fin.
0.9 < F. 1002:1002(0) ack 102 win 244
0.9 > . 102:102(0) ack 1002 win 244

// Peer reopens with in-window SYN:
1.000 < S 1000:1000(0) win 9200 

// Therefore, reply with ACK.
1.000 > . 102:102(0) ack 1002 win 244

// Peer sends RST for this ACK.  Normally this RST results
// in tw socket removal, but rfc1337=1 setting prevents this.
1.100 < R 1002:1002(0) win 244

// second syn. Due to rfc1337=1 expect another pure ACK.
31.0 < S 1000:1000(0) win 9200 
31.0 > . 102:102(0) ack 1002 win 244

// .. and another RST from peer.
31.1 < R 1002:1002(0) win 244
31.2 `echo no timer restart;ss -m -e -a -i -n -t -o state TIME-WAIT`

// third syn after one minute.  Time-Wait socket should have expired by now.
63.0 < S 1000:1000(0) win 9200 

// so we expect a syn-ack & 3whs to proceed from here on.
63.0 > S. 0:0(0) ack 1 

Without this patch, 'ss' shows restarts of tw timer and last packet is
thus just another pure ack, more than one minute later.

This restores the original code from commit 283fd6cf0be690a83
("Merge in ANK networking jumbo patch") in netdev-vger-cvs.git .

For some reason the else branch was removed/lost in 1f28b683339f7
("Merge in TCP/UDP optimizations and [..]") and timer restart became
unconditional.

Reported-by: Michal Tesar 
Signed-off-by: Florian Westphal 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

netfilter: kconfig: nat related expression depend on nftables core

2018-08-31T17:07:10+00:00

NF_TABLES_IPV4 is now boolean so it is possible to set

NF_TABLES=m
NF_TABLES_IPV4=y
NFT_CHAIN_NAT_IPV4=y

which causes:
nft_chain_nat_ipv4.c:(.text+0x6d): undefined reference to `nft_do_chain'

Wrap NFT_CHAIN_NAT_IPV4 and related nat expressions with NF_TABLES to
restore the dependency.

Reported-by: Randy Dunlap 
Fixes: 02c7b25e5f54 ("netfilter: nf_tables: build-in filter chain type")
Signed-off-by: Florian Westphal 
Acked-by: Randy Dunlap 
Signed-off-by: Pablo Neira Ayuso