8040 Commits

Author SHA1 Message Date
Mao Wenan
44d2ea6ef6 net: Update window_clamp if SOCK_RCVBUF is set
[ Upstream commit 909172a149749242990a6e64cb55d55460d4e417 ]

When net.ipv4.tcp_syncookies=1 and syn flood is happened,
cookie_v4_check or cookie_v6_check tries to redo what
tcp_v4_send_synack or tcp_v6_send_synack did,
rsk_window_clamp will be changed if SOCK_RCVBUF is set,
which will make rcv_wscale is different, the client
still operates with initial window scale and can overshot
granted window, the client use the initial scale but local
server use new scale to advertise window value, and session
work abnormally.

Fixes: e88c64f0a425 ("tcp: allow effective reduction of TCP's rcv-buffer via setsockopt")
Signed-off-by: Mao Wenan <wenan.mao@linux.alibaba.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/1604967391-123737-1-git-send-email-wenan.mao@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18 18:26:29 +01:00
Eric Dumazet
df838165a1 icmp: randomize the global rate limiter
[ Upstream commit b38e7819cae946e2edf869e604af1e65a5d241c5 ]

Keyu Man reported that the ICMP rate limiter could be used
by attackers to get useful signal. Details will be provided
in an upcoming academic publication.

Our solution is to add some noise, so that the attackers
no longer can get help from the predictable token bucket limiter.

Fixes: 4cdf507d5452 ("icmp: add a global rate limitation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29 09:05:32 +01:00
Neal Cardwell
090178ce6f tcp: fix to update snd_wl1 in bulk receiver fast path
[ Upstream commit 18ded910b589839e38a51623a179837ab4cc3789 ]

In the header prediction fast path for a bulk data receiver, if no
data is newly acknowledged then we do not call tcp_ack() and do not
call tcp_ack_update_window(). This means that a bulk receiver that
receives large amounts of data can have the incoming sequence numbers
wrap, so that the check in tcp_may_update_window fails:
   after(ack_seq, tp->snd_wl1)

If the incoming receive windows are zero in this state, and then the
connection that was a bulk data receiver later wants to send data,
that connection can find itself persistently rejecting the window
updates in incoming ACKs. This means the connection can persistently
fail to discover that the receive window has opened, which in turn
means that the connection is unable to send anything, and the
connection's sending process can get permanently "stuck".

The fix is to update snd_wl1 in the header prediction fast path for a
bulk data receiver, so that it keeps up and does not see wrapping
problems.

This fix is based on a very nice and thorough analysis and diagnosis
by Apollon Oikonomopoulos (see link below).

This is a stable candidate but there is no Fixes tag here since the
bug predates current git history. Just for fun: looks like the bug
dates back to when header prediction was added in Linux v2.1.8 in Nov
1996. In that version tcp_rcv_established() was added, and the code
only updates snd_wl1 in tcp_ack(), and in the new "Bulk data transfer:
receiver" code path it does not call tcp_ack(). This fix seems to
apply cleanly at least as far back as v3.2.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reported-by: Apollon Oikonomopoulos <apoikos@dmesg.gr>
Tested-by: Apollon Oikonomopoulos <apoikos@dmesg.gr>
Link: https://www.spinics.net/lists/netdev/msg692430.html
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20201022143331.1887495-1-ncardwell.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29 09:05:32 +01:00
Vasily Averin
c10bfe7335 rt_cpu_seq_next should increase position index
[ Upstream commit a3ea86739f1bc7e121d921842f0f4a8ab1af94d9 ]

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 20:40:04 +02:00
Wei Wang
03c034c8e4 ip: fix tos reflection in ack and reset packets
[ Upstream commit ba9e04a7ddf4f22a10e05bf9403db6b97743c7bf ]

Currently, in tcp_v4_reqsk_send_ack() and tcp_v4_send_reset(), we
echo the TOS value of the received packets in the response.
However, we do not want to echo the lower 2 ECN bits in accordance
with RFC 3168 6.1.5 robustness principles.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01 20:40:00 +02:00
Tim Froidcoeur
d370e95778 net: initialize fastreuse on inet_inherit_port
commit d76f3351cea2d927fdf70dd7c06898235035e84e upstream.

In the case of TPROXY, bind_conflict optimizations for SO_REUSEADDR or
SO_REUSEPORT are broken, possibly resulting in O(n) instead of O(1) bind
behaviour or in the incorrect reuse of a bind.

the kernel keeps track for each bind_bucket if all sockets in the
bind_bucket support SO_REUSEADDR or SO_REUSEPORT in two fastreuse flags.
These flags allow skipping the costly bind_conflict check when possible
(meaning when all sockets have the proper SO_REUSE option).

For every socket added to a bind_bucket, these flags need to be updated.
As soon as a socket that does not support reuse is added, the flag is
set to false and will never go back to true, unless the bind_bucket is
deleted.

Note that there is no mechanism to re-evaluate these flags when a socket
is removed (this might make sense when removing a socket that would not
allow reuse; this leaves room for a future patch).

For this optimization to work, it is mandatory that these flags are
properly initialized and updated.

When a child socket is created from a listen socket in
__inet_inherit_port, the TPROXY case could create a new bind bucket
without properly initializing these flags, thus preventing the
optimization to work. Alternatively, a socket not allowing reuse could
be added to an existing bind bucket without updating the flags, causing
bind_conflict to never be called as it should.

Call inet_csk_update_fastreuse when __inet_inherit_port decides to create
a new bind_bucket or use a different bind_bucket than the one of the
listen socket.

Fixes: 093d282321da ("tproxy: fix hash locking issue when using port redirection in __inet_inherit_port()")
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Tim Froidcoeur <tim.froidcoeur@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Tim Froidcoeur <tim.froidcoeur@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12 11:47:38 +02:00
Tim Froidcoeur
f4461490c3 net: refactor bind_bucket fastreuse into helper
commit 62ffc589abb176821662efc4525ee4ac0b9c3894 upstream.

Refactor the fastreuse update code in inet_csk_get_port into a small
helper function that can be called from other places.

Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Tim Froidcoeur <tim.froidcoeur@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Tim Froidcoeur <tim.froidcoeur@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12 11:47:38 +02:00
Ido Schimmel
f81f591e14 ipv4: Silence suspicious RCU usage warning
[ Upstream commit 83f3522860f702748143e022f1a546547314c715 ]

fib_trie_unmerge() is called with RTNL held, but not from an RCU
read-side critical section. This leads to the following warning [1] when
the FIB alias list in a leaf is traversed with
hlist_for_each_entry_rcu().

Since the function is always called with RTNL held and since
modification of the list is protected by RTNL, simply use
hlist_for_each_entry() and silence the warning.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Not tainted
-----------------------------
net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/164:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

stack backtrace:
CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 fib_trie_unmerge+0x608/0xdb0
 fib_unmerge+0x44/0x360
 fib4_rule_configure+0xc8/0xad0
 fib_nl_newrule+0x37a/0x1dd0
 rtnetlink_rcv_msg+0x4f7/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 ____sys_sendmsg+0x879/0xa00
 ___sys_sendmsg+0x122/0x190
 __sys_sendmsg+0x103/0x1d0
 __x64_sys_sendmsg+0x7d/0xb0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc80a234e97
Code: Bad RIP value.
RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97
RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003
RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020

Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:01:55 +02:00
Yuchung Cheng
35c3c8f01c tcp: allow at most one TLP probe per flight
[ Upstream commit 76be93fc0702322179bb0ea87295d820ee46ad14 ]

Previously TLP may send multiple probes of new data in one
flight. This happens when the sender is cwnd limited. After the
initial TLP containing new data is sent, the sender receives another
ACK that acks partial inflight.  It may re-arm another TLP timer
to send more, if no further ACK returns before the next TLP timeout
(PTO) expires. The sender may send in theory a large amount of TLP
until send queue is depleted. This only happens if the sender sees
such irregular uncommon ACK pattern. But it is generally undesirable
behavior during congestion especially.

The original TLP design restrict only one TLP probe per inflight as
published in "Reducing Web Latency: the Virtue of Gentle Aggression",
SIGCOMM 2013. This patch changes TLP to send at most one probe
per inflight.

Note that if the sender is app-limited, TLP retransmits old data
and did not have this issue.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31 16:44:06 +02:00
Miaohe Lin
feed32a3a4 net: udp: Fix wrong clean up for IS_UDPLITE macro
[ Upstream commit b0a422772fec29811e293c7c0e6f991c0fd9241d ]

We can't use IS_UDPLITE to replace udp_sk->pcflag when UDPLITE_RECV_CC is
checked.

Fixes: b2bf1e2659b1 ("[UDP]: Clean up for IS_UDPLITE macro")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31 16:44:06 +02:00
Eric Dumazet
2d00b78d54 tcp: md5: allow changing MD5 keys in all socket states
[ Upstream commit 1ca0fafd73c5268e8fc4b997094b8bb2bfe8deea ]

This essentially reverts commit 721230326891 ("tcp: md5: reject TCP_MD5SIG
or TCP_MD5SIG_EXT on established sockets")

Mathieu reported that many vendors BGP implementations can
actually switch TCP MD5 on established flows.

Quoting Mathieu :
   Here is a list of a few network vendors along with their behavior
   with respect to TCP MD5:

   - Cisco: Allows for password to be changed, but within the hold-down
     timer (~180 seconds).
   - Juniper: When password is initially set on active connection it will
     reset, but after that any subsequent password changes no network
     resets.
   - Nokia: No notes on if they flap the tcp connection or not.
   - Ericsson/RedBack: Allows for 2 password (old/new) to co-exist until
     both sides are ok with new passwords.
   - Meta-Switch: Expects the password to be set before a connection is
     attempted, but no further info on whether they reset the TCP
     connection on a change.
   - Avaya: Disable the neighbor, then set password, then re-enable.
   - Zebos: Would normally allow the change when socket connected.

We can revert my prior change because commit 9424e2e7ad93 ("tcp: md5: fix potential
overestimation of TCP option space") removed the leak of 4 kernel bytes to
the wire that was the main reason for my patch.

While doing my investigations, I found a bug when a MD5 key is changed, leading
to these commits that stable teams want to consider before backporting this revert :

 Commit 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()")
 Commit e6ced831ef11 ("tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriers")

Fixes: 721230326891 "tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets"
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:10:48 +02:00
Eric Dumazet
ade339f5fc tcp: md5: do not send silly options in SYNCOOKIES
[ Upstream commit e114e1e8ac9d31f25b9dd873bab5d80c1fc482ca ]

Whenever cookie_init_timestamp() has been used to encode
ECN,SACK,WSCALE options, we can not remove the TS option in the SYNACK.

Otherwise, tcp_synack_options() will still advertize options like WSCALE
that we can not deduce later when receiving the packet from the client
to complete 3WHS.

Note that modern linux TCP stacks wont use MD5+TS+SACK in a SYN packet,
but we can not know for sure that all TCP stacks have the same logic.

Before the fix a tcpdump would exhibit this wrong exchange :

10:12:15.464591 IP C > S: Flags [S], seq 4202415601, win 65535, options [nop,nop,md5 valid,mss 1400,sackOK,TS val 456965269 ecr 0,nop,wscale 8], length 0
10:12:15.464602 IP S > C: Flags [S.], seq 253516766, ack 4202415602, win 65535, options [nop,nop,md5 valid,mss 1400,nop,nop,sackOK,nop,wscale 8], length 0
10:12:15.464611 IP C > S: Flags [.], ack 1, win 256, options [nop,nop,md5 valid], length 0
10:12:15.464678 IP C > S: Flags [P.], seq 1:13, ack 1, win 256, options [nop,nop,md5 valid], length 12
10:12:15.464685 IP S > C: Flags [.], ack 13, win 65535, options [nop,nop,md5 valid], length 0

After this patch the exchange looks saner :

11:59:59.882990 IP C > S: Flags [S], seq 517075944, win 65535, options [nop,nop,md5 valid,mss 1400,sackOK,TS val 1751508483 ecr 0,nop,wscale 8], length 0
11:59:59.883002 IP S > C: Flags [S.], seq 1902939253, ack 517075945, win 65535, options [nop,nop,md5 valid,mss 1400,sackOK,TS val 1751508479 ecr 1751508483,nop,wscale 8], length 0
11:59:59.883012 IP C > S: Flags [.], ack 1, win 256, options [nop,nop,md5 valid,nop,nop,TS val 1751508483 ecr 1751508479], length 0
11:59:59.883114 IP C > S: Flags [P.], seq 1:13, ack 1, win 256, options [nop,nop,md5 valid,nop,nop,TS val 1751508483 ecr 1751508479], length 12
11:59:59.883122 IP S > C: Flags [.], ack 13, win 256, options [nop,nop,md5 valid,nop,nop,TS val 1751508483 ecr 1751508483], length 0
11:59:59.883152 IP S > C: Flags [P.], seq 1:13, ack 13, win 256, options [nop,nop,md5 valid,nop,nop,TS val 1751508484 ecr 1751508483], length 12
11:59:59.883170 IP C > S: Flags [.], ack 13, win 256, options [nop,nop,md5 valid,nop,nop,TS val 1751508484 ecr 1751508484], length 0

Of course, no SACK block will ever be added later, but nothing should break.
Technically, we could remove the 4 nops included in MD5+TS options,
but again some stacks could break seeing not conventional alignment.

Fixes: 4957faade11b ("TCPCT part 1g: Responder Cookie => Initiator")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:10:48 +02:00
Christoph Paasch
35e7d27c71 tcp: make sure listeners don't initialize congestion-control state
[ Upstream commit ce69e563b325f620863830c246a8698ccea52048 ]

syzkaller found its way into setsockopt with TCP_CONGESTION "cdg".
tcp_cdg_init() does a kcalloc to store the gradients. As sk_clone_lock
just copies all the memory, the allocated pointer will be copied as
well, if the app called setsockopt(..., TCP_CONGESTION) on the listener.
If now the socket will be destroyed before the congestion-control
has properly been initialized (through a call to tcp_init_transfer), we
will end up freeing memory that does not belong to that particular
socket, opening the door to a double-free:

[   11.413102] ==================================================================
[   11.414181] BUG: KASAN: double-free or invalid-free in tcp_cleanup_congestion_control+0x58/0xd0
[   11.415329]
[   11.415560] CPU: 3 PID: 4884 Comm: syz-executor.5 Not tainted 5.8.0-rc2 #80
[   11.416544] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[   11.418148] Call Trace:
[   11.418534]  <IRQ>
[   11.418834]  dump_stack+0x7d/0xb0
[   11.419297]  print_address_description.constprop.0+0x1a/0x210
[   11.422079]  kasan_report_invalid_free+0x51/0x80
[   11.423433]  __kasan_slab_free+0x15e/0x170
[   11.424761]  kfree+0x8c/0x230
[   11.425157]  tcp_cleanup_congestion_control+0x58/0xd0
[   11.425872]  tcp_v4_destroy_sock+0x57/0x5a0
[   11.426493]  inet_csk_destroy_sock+0x153/0x2c0
[   11.427093]  tcp_v4_syn_recv_sock+0xb29/0x1100
[   11.427731]  tcp_get_cookie_sock+0xc3/0x4a0
[   11.429457]  cookie_v4_check+0x13d0/0x2500
[   11.433189]  tcp_v4_do_rcv+0x60e/0x780
[   11.433727]  tcp_v4_rcv+0x2869/0x2e10
[   11.437143]  ip_protocol_deliver_rcu+0x23/0x190
[   11.437810]  ip_local_deliver+0x294/0x350
[   11.439566]  __netif_receive_skb_one_core+0x15d/0x1a0
[   11.441995]  process_backlog+0x1b1/0x6b0
[   11.443148]  net_rx_action+0x37e/0xc40
[   11.445361]  __do_softirq+0x18c/0x61a
[   11.445881]  asm_call_on_stack+0x12/0x20
[   11.446409]  </IRQ>
[   11.446716]  do_softirq_own_stack+0x34/0x40
[   11.447259]  do_softirq.part.0+0x26/0x30
[   11.447827]  __local_bh_enable_ip+0x46/0x50
[   11.448406]  ip_finish_output2+0x60f/0x1bc0
[   11.450109]  __ip_queue_xmit+0x71c/0x1b60
[   11.451861]  __tcp_transmit_skb+0x1727/0x3bb0
[   11.453789]  tcp_rcv_state_process+0x3070/0x4d3a
[   11.456810]  tcp_v4_do_rcv+0x2ad/0x780
[   11.457995]  __release_sock+0x14b/0x2c0
[   11.458529]  release_sock+0x4a/0x170
[   11.459005]  __inet_stream_connect+0x467/0xc80
[   11.461435]  inet_stream_connect+0x4e/0xa0
[   11.462043]  __sys_connect+0x204/0x270
[   11.465515]  __x64_sys_connect+0x6a/0xb0
[   11.466088]  do_syscall_64+0x3e/0x70
[   11.466617]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   11.467341] RIP: 0033:0x7f56046dc469
[   11.467844] Code: Bad RIP value.
[   11.468282] RSP: 002b:00007f5604dccdd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
[   11.469326] RAX: ffffffffffffffda RBX: 000000000068bf00 RCX: 00007f56046dc469
[   11.470379] RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000004
[   11.471311] RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
[   11.472286] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[   11.473341] R13: 000000000041427c R14: 00007f5604dcd5c0 R15: 0000000000000003
[   11.474321]
[   11.474527] Allocated by task 4884:
[   11.475031]  save_stack+0x1b/0x40
[   11.475548]  __kasan_kmalloc.constprop.0+0xc2/0xd0
[   11.476182]  tcp_cdg_init+0xf0/0x150
[   11.476744]  tcp_init_congestion_control+0x9b/0x3a0
[   11.477435]  tcp_set_congestion_control+0x270/0x32f
[   11.478088]  do_tcp_setsockopt.isra.0+0x521/0x1a00
[   11.478744]  __sys_setsockopt+0xff/0x1e0
[   11.479259]  __x64_sys_setsockopt+0xb5/0x150
[   11.479895]  do_syscall_64+0x3e/0x70
[   11.480395]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   11.481097]
[   11.481321] Freed by task 4872:
[   11.481783]  save_stack+0x1b/0x40
[   11.482230]  __kasan_slab_free+0x12c/0x170
[   11.482839]  kfree+0x8c/0x230
[   11.483240]  tcp_cleanup_congestion_control+0x58/0xd0
[   11.483948]  tcp_v4_destroy_sock+0x57/0x5a0
[   11.484502]  inet_csk_destroy_sock+0x153/0x2c0
[   11.485144]  tcp_close+0x932/0xfe0
[   11.485642]  inet_release+0xc1/0x1c0
[   11.486131]  __sock_release+0xc0/0x270
[   11.486697]  sock_close+0xc/0x10
[   11.487145]  __fput+0x277/0x780
[   11.487632]  task_work_run+0xeb/0x180
[   11.488118]  __prepare_exit_to_usermode+0x15a/0x160
[   11.488834]  do_syscall_64+0x4a/0x70
[   11.489326]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Wei Wang fixed a part of these CDG-malloc issues with commit c12014440750
("tcp: memset ca_priv data to 0 properly").

This patch here fixes the listener-scenario: We make sure that listeners
setting the congestion-control through setsockopt won't initialize it
(thus CDG never allocates on listeners). For those who use AF_UNSPEC to
reuse a socket, tcp_disconnect() is changed to cleanup afterwards.

(The issue can be reproduced at least down to v4.4.x.)

Cc: Wei Wang <weiwan@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Fixes: 2b0a8c9eee81 ("tcp: add CDG congestion control")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:10:48 +02:00
Eric Dumazet
66486965c3 tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriers
[ Upstream commit e6ced831ef11a2a06e8d00aad9d4fc05b610bf38 ]

My prior fix went a bit too far, according to Herbert and Mathieu.

Since we accept that concurrent TCP MD5 lookups might see inconsistent
keys, we can use READ_ONCE()/WRITE_ONCE() instead of smp_rmb()/smp_wmb()

Clearing all key->key[] is needed to avoid possible KMSAN reports,
if key->keylen is increased. Since tcp_md5_do_add() is not fast path,
using __GFP_ZERO to clear all struct tcp_md5sig_key is simpler.

data_race() was added in linux-5.8 and will prevent KCSAN reports,
this can safely be removed in stable backports, if data_race() is
not yet backported.

v2: use data_race() both in tcp_md5_hash_key() and tcp_md5_do_add()

Fixes: 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marco Elver <elver@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:10:48 +02:00
Eric Dumazet
d9e26f65ff tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()
[ Upstream commit 6a2febec338df7e7699a52d00b2e1207dcf65b28 ]

MD5 keys are read with RCU protection, and tcp_md5_do_add()
might update in-place a prior key.

Normally, typical RCU updates would allocate a new piece
of memory. In this case only key->key and key->keylen might
be updated, and we do not care if an incoming packet could
see the old key, the new one, or some intermediate value,
since changing the key on a live flow is known to be problematic
anyway.

We only want to make sure that in the case key->keylen
is changed, cpus in tcp_md5_hash_key() wont try to use
uninitialized data, or crash because key->keylen was
read twice to feed sg_init_one() and ahash_request_set_crypt()

Fixes: 9ea88a153001 ("tcp: md5: check md5 signature without socket lock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:10:48 +02:00
Sabrina Dubroca
55159973e1 ipv4: fill fl4_icmp_{type,code} in ping_v4_sendmsg
[ Upstream commit 5eff06902394425c722f0a44d9545909a8800f79 ]

IPv4 ping sockets don't set fl4.fl4_icmp_{type,code}, which leads to
incomplete IPsec ACQUIRE messages being sent to userspace. Currently,
both raw sockets and IPv6 ping sockets set those fields.

Expected output of "ip xfrm monitor":
    acquire proto esp
      sel src 10.0.2.15/32 dst 8.8.8.8/32 proto icmp type 8 code 0 dev ens4
      policy src 10.0.2.15/32 dst 8.8.8.8/32
        <snip>

Currently with ping sockets:
    acquire proto esp
      sel src 10.0.2.15/32 dst 8.8.8.8/32 proto icmp type 0 code 0 dev ens4
      policy src 10.0.2.15/32 dst 8.8.8.8/32
        <snip>

The Libreswan test suite found this problem after Fedora changed the
value for the sysctl net.ipv4.ping_group_range.

Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Reported-by: Paul Wouters <pwouters@redhat.com>
Tested-by: Paul Wouters <pwouters@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:10:47 +02:00
guodeqing
6ac341cec7 net: Fix the arp error in some cases
[ Upstream commit 5eea3a63ff4aba6a26002e657a6d21934b7e2b96 ]

ie.,
$ ifconfig eth0 6.6.6.6 netmask 255.255.255.0

$ ip rule add from 6.6.6.6 table 6666

$ ip route add 9.9.9.9 via 6.6.6.6

$ ping -I 6.6.6.6 9.9.9.9
PING 9.9.9.9 (9.9.9.9) from 6.6.6.6 : 56(84) bytes of data.

3 packets transmitted, 0 received, 100% packet loss, time 2079ms

$ arp
Address     HWtype  HWaddress           Flags Mask            Iface
6.6.6.6             (incomplete)                              eth0

The arp request address is error, this is because fib_table_lookup in
fib_check_nh lookup the destnation 9.9.9.9 nexthop, the scope of
the fib result is RT_SCOPE_LINK,the correct scope is RT_SCOPE_HOST.
Here I add a check of whether this is RT_TABLE_MAIN to solve this problem.

Fixes: 3bfd847203c6 ("net: Use passed in table for nexthop lookups")
Signed-off-by: guodeqing <geffrey.guo@huawei.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 15:38:39 -04:00
Eric Dumazet
05cc823542 tcp: grow window for OOO packets only for SACK flows
[ Upstream commit 662051215c758ae8545451628816204ed6cd372d ]

Back in 2013, we made a change that broke fast retransmit
for non SACK flows.

Indeed, for these flows, a sender needs to receive three duplicate
ACK before starting fast retransmit. Sending ACK with different
receive window do not count.

Even if enabling SACK is strongly recommended these days,
there still are some cases where it has to be disabled.

Not increasing the window seems better than having to
rely on RTO.

After the fix, following packetdrill test gives :

// Initialize connection
    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

   +0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7>
   +0 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 8>
   +0 < . 1:1(0) ack 1 win 514

   +0 accept(3, ..., ...) = 4

   +0 < . 1:1001(1000) ack 1 win 514
// Quick ack
   +0 > . 1:1(0) ack 1001 win 264

   +0 < . 2001:3001(1000) ack 1 win 514
// DUPACK : Normally we should not change the window
   +0 > . 1:1(0) ack 1001 win 264

   +0 < . 3001:4001(1000) ack 1 win 514
// DUPACK : Normally we should not change the window
   +0 > . 1:1(0) ack 1001 win 264

   +0 < . 4001:5001(1000) ack 1 win 514
// DUPACK : Normally we should not change the window
    +0 > . 1:1(0) ack 1001 win 264

   +0 < . 1001:2001(1000) ack 1 win 514
// Hole is repaired.
   +0 > . 1:1(0) ack 5001 win 272

Fixes: 4e4f1fc22681 ("tcp: properly increase rcv_ssthresh for ofo packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 15:38:39 -04:00
Neal Cardwell
98d3884bfa tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT
[ Upstream commit b344579ca8478598937215f7005d6c7b84d28aee ]

Mirja Kuehlewind reported a bug in Linux TCP CUBIC Hystart, where
Hystart HYSTART_DELAY mechanism can exit Slow Start spuriously on an
ACK when the minimum rtt of a connection goes down. From inspection it
is clear from the existing code that this could happen in an example
like the following:

o The first 8 RTT samples in a round trip are 150ms, resulting in a
  curr_rtt of 150ms and a delay_min of 150ms.

o The 9th RTT sample is 100ms. The curr_rtt does not change after the
  first 8 samples, so curr_rtt remains 150ms. But delay_min can be
  lowered at any time, so delay_min falls to 100ms. The code executes
  the HYSTART_DELAY comparison between curr_rtt of 150ms and delay_min
  of 100ms, and the curr_rtt is declared far enough above delay_min to
  force a (spurious) exit of Slow start.

The fix here is simple: allow every RTT sample in a round trip to
lower the curr_rtt.

Fixes: ae27e98a5152 ("[TCP] CUBIC v2.3")
Reported-by: Mirja Kuehlewind <mirja.kuehlewind@ericsson.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 15:38:39 -04:00
Taehee Yoo
ae1c468be6 ip_tunnel: fix use-after-free in ip_tunnel_lookup()
[ Upstream commit ba61539c6ae57f4146284a5cb4f7b7ed8d42bf45 ]

In the datapath, the ip_tunnel_lookup() is used and it internally uses
fallback tunnel device pointer, which is fb_tunnel_dev.
This pointer variable should be set to NULL when a fb interface is deleted.
But there is no routine to set fb_tunnel_dev pointer to NULL.
So, this pointer will be still used after interface is deleted and
it eventually results in the use-after-free problem.

Test commands:
    ip netns add A
    ip netns add B
    ip link add eth0 type veth peer name eth1
    ip link set eth0 netns A
    ip link set eth1 netns B

    ip netns exec A ip link set lo up
    ip netns exec A ip link set eth0 up
    ip netns exec A ip link add gre1 type gre local 10.0.0.1 \
	    remote 10.0.0.2
    ip netns exec A ip link set gre1 up
    ip netns exec A ip a a 10.0.100.1/24 dev gre1
    ip netns exec A ip a a 10.0.0.1/24 dev eth0

    ip netns exec B ip link set lo up
    ip netns exec B ip link set eth1 up
    ip netns exec B ip link add gre1 type gre local 10.0.0.2 \
	    remote 10.0.0.1
    ip netns exec B ip link set gre1 up
    ip netns exec B ip a a 10.0.100.2/24 dev gre1
    ip netns exec B ip a a 10.0.0.2/24 dev eth1
    ip netns exec A hping3 10.0.100.2 -2 --flood -d 60000 &
    ip netns del B

Splat looks like:
[   77.793450][    C3] ==================================================================
[   77.794702][    C3] BUG: KASAN: use-after-free in ip_tunnel_lookup+0xcc4/0xf30
[   77.795573][    C3] Read of size 4 at addr ffff888060bd9c84 by task hping3/2905
[   77.796398][    C3]
[   77.796664][    C3] CPU: 3 PID: 2905 Comm: hping3 Not tainted 5.8.0-rc1+ #616
[   77.797474][    C3] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   77.798453][    C3] Call Trace:
[   77.798815][    C3]  <IRQ>
[   77.799142][    C3]  dump_stack+0x9d/0xdb
[   77.799605][    C3]  print_address_description.constprop.7+0x2cc/0x450
[   77.800365][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.800908][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.801517][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.802145][    C3]  kasan_report+0x154/0x190
[   77.802821][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.803503][    C3]  ip_tunnel_lookup+0xcc4/0xf30
[   77.804165][    C3]  __ipgre_rcv+0x1ab/0xaa0 [ip_gre]
[   77.804862][    C3]  ? rcu_read_lock_sched_held+0xc0/0xc0
[   77.805621][    C3]  gre_rcv+0x304/0x1910 [ip_gre]
[   77.806293][    C3]  ? lock_acquire+0x1a9/0x870
[   77.806925][    C3]  ? gre_rcv+0xfe/0x354 [gre]
[   77.807559][    C3]  ? erspan_xmit+0x2e60/0x2e60 [ip_gre]
[   77.808305][    C3]  ? rcu_read_lock_sched_held+0xc0/0xc0
[   77.809032][    C3]  ? rcu_read_lock_held+0x90/0xa0
[   77.809713][    C3]  gre_rcv+0x1b8/0x354 [gre]
[ ... ]

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 15:38:38 -04:00
Yang Yingliang
d2d5111481 devinet: fix memleak in inetdev_init()
[ Upstream commit 1b49cd71b52403822731dc9f283185d1da355f97 ]

When devinet_sysctl_register() failed, the memory allocated
in neigh_parms_alloc() should be freed.

Fixes: 20e61da7ffcf ("ipv4: fail early when creating netdev named all or default")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-11 09:22:21 +02:00
Pablo Neira Ayuso
8ef576491c netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code
commit 4c559f15efcc43b996f4da528cd7f9483aaca36d upstream.

Dan Carpenter says: "Smatch complains that the value for "cmd" comes
from the network and can't be trusted."

Add pptp_msg_name() helper function that checks for the array boundary.

Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:16:46 +02:00
Xin Long
c67ec7f940 ip_vti: receive ipip packet by calling ip_tunnel_rcv
commit 976eba8ab596bab94b9714cd46d38d5c6a2c660d upstream.

In Commit dd9ee3444014 ("vti4: Fix a ipip packet processing bug in
'IPCOMP' virtual tunnel"), it tries to receive IPIP packets in vti
by calling xfrm_input(). This case happens when a small packet or
frag sent by peer is too small to get compressed.

However, xfrm_input() will still get to the IPCOMP path where skb
sec_path is set, but never dropped while it should have been done
in vti_ipcomp4_protocol.cb_handler(vti_rcv_cb), as it's not an
ipcomp4 packet. This will cause that the packet can never pass
xfrm4_policy_check() in the upper protocol rcv functions.

So this patch is to call ip_tunnel_rcv() to process IPIP packets
instead.

Fixes: dd9ee3444014 ("vti4: Fix a ipip packet processing bug in 'IPCOMP' virtual tunnel")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:16:45 +02:00
Jeremy Sowden
60dbd1a369 vti4: eliminated some duplicate code.
commit f981c57ffd2d7cf2dd4b6d6f8fcb3965df42f54c upstream.

The ipip tunnel introduced in commit dd9ee3444014 ("vti4: Fix a ipip
packet processing bug in 'IPCOMP' virtual tunnel") largely duplicated
the existing vti_input and vti_recv functions.  Refactored to
deduplicate the common code.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:16:44 +02:00
Yuqi Jin
f08aeb334b net: revert "net: get rid of an signed integer overflow in ip_idents_reserve()"
[ Upstream commit a6211caa634da39d861a47437ffcda8b38ef421b ]

Commit adb03115f459 ("net: get rid of an signed integer overflow in ip_idents_reserve()")
used atomic_cmpxchg to replace "atomic_add_return" inside the function
"ip_idents_reserve". The reason was to avoid UBSAN warning.
However, this change has caused performance degrade and in GCC-8,
fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer
and signed integer overflow is now undefined by default at all
optimization levels[1]. Moreover, it was a bug in UBSAN vs -fwrapv
/-fno-strict-overflow, so Let's revert it safely.

[1] https://gcc.gnu.org/gcc-8/changes.html

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiong Wang <jiongwang@huawei.com>
Signed-off-by: Yuqi Jin <jinyuqi@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:16:24 +02:00
Vadim Fedorenko
72e2d903bd net: ipip: fix wrong address family in init error path
[ Upstream commit 57ebc8f08504f176eb0f25b3e0fde517dec61a4f ]

In case of error with MPLS support the code is misusing AF_INET
instead of AF_MPLS.

Fixes: 1b69e7e6c4da ("ipip: support MPLS over IPv4")
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:16:23 +02:00
Paolo Abeni
be38a13c9e net: ipv4: really enforce backoff for redirects
[ Upstream commit 57644431a6c2faac5d754ebd35780cf43a531b1a ]

In commit b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and
rate_tokens usage") I missed the fact that a 0 'rate_tokens' will
bypass the backoff algorithm.

Since rate_tokens is cleared after a redirect silence, and never
incremented on redirects, if the host keeps receiving packets
requiring redirect it will reply ignoring the backoff.

Additionally, the 'rate_last' field will be updated with the
cadence of the ingress packet requiring redirect. If that rate is
high enough, that will prevent the host from generating any
other kind of ICMP messages

The check for a zero 'rate_tokens' value was likely a shortcut
to avoid the more complex backoff algorithm after a redirect
silence period. Address the issue checking for 'n_redirects'
instead, which is incremented on successful redirect, and
does not interfere with other ICMP replies.

Fixes: b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and rate_tokens usage")
Reported-and-tested-by: Colin Walters <walters@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20 08:15:39 +02:00
Paolo Abeni
9232577ef3 netlabel: cope with NULL catmap
[ Upstream commit eead1c2ea2509fd754c6da893a94f0e69e83ebe4 ]

The cipso and calipso code can set the MLS_CAT attribute on
successful parsing, even if the corresponding catmap has
not been allocated, as per current configuration and external
input.

Later, selinux code tries to access the catmap if the MLS_CAT flag
is present via netlbl_catmap_getlong(). That may cause null ptr
dereference while processing incoming network traffic.

Address the issue setting the MLS_CAT flag only if the catmap is
really allocated. Additionally let netlbl_catmap_getlong() cope
with NULL catmap.

Reported-by: Matthew Sheets <matthew.sheets@gd-ms.com>
Fixes: 4b8feff251da ("netlabel: fix the horribly broken catmap functions")
Fixes: ceba1832b1b2 ("calipso: Set the calipso socket label to match the secattr.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20 08:15:39 +02:00
David Ahern
d95f959a93 xfrm: Always set XFRM_TRANSFORMED in xfrm{4,6}_output_finish
[ Upstream commit 0c922a4850eba2e668f73a3f1153196e09abb251 ]

IPSKB_XFRM_TRANSFORMED and IP6SKB_XFRM_TRANSFORMED are skb flags set by
xfrm code to tell other skb handlers that the packet has been passed
through the xfrm output functions. Simplify the code and just always
set them rather than conditionally based on netfilter enabled thus
making the flag available for other users.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:23:09 +02:00
Jeremy Sowden
1dd76d0551 vti4: removed duplicate log message.
commit 01ce31c57b3f07c91c9d45bbaf126124cce83a5d upstream.

Removed info log-message if ipip tunnel registration fails during
module-initialization: it adds nothing to the error message that is
written on all failures.

Fixes: dd9ee3444014e ("vti4: Fix a ipip packet processing bug in 'IPCOMP' virtual tunnel")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:23:01 +02:00
Arnd Bergmann
bcdb7d9ea3 net: ipv4: avoid unused variable warning for sysctl
commit 773daa3caf5d3f87fdb1ab43e9c1b367a38fa394 upstream.

The newly introudced ip_min_valid_pmtu variable is only used when
CONFIG_SYSCTL is set:

net/ipv4/route.c:135:12: error: 'ip_min_valid_pmtu' defined but not used [-Werror=unused-variable]

This moves it to the other variables like it, to avoid the harmless
warning.

Fixes: c7272c2f1229 ("net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:22:57 +02:00
Nicolai Stange
5656000280 net: ipv4: emulate READ_ONCE() on ->hdrincl bit-field in raw_sendmsg()
commit 20b50d79974ea3192e8c3ab7faf4e536e5f14d8f upstream.

Commit 8f659a03a0ba ("net: ipv4: fix for a race condition in
raw_sendmsg") fixed the issue of possibly inconsistent ->hdrincl handling
due to concurrent updates by reading this bit-field member into a local
variable and using the thus stabilized value in subsequent tests.

However, aforementioned commit also adds the (correct) comment that

  /* hdrincl should be READ_ONCE(inet->hdrincl)
   * but READ_ONCE() doesn't work with bit fields
   */

because as it stands, the compiler is free to shortcut or even eliminate
the local variable at its will.

Note that I have not seen anything like this happening in reality and thus,
the concern is a theoretical one.

However, in order to be on the safe side, emulate a READ_ONCE() on the
bit-field by doing it on the local 'hdrincl' variable itself:

	int hdrincl = inet->hdrincl;
	hdrincl = READ_ONCE(hdrincl);

This breaks the chain in the sense that the compiler is not allowed
to replace subsequent reads from hdrincl with reloads from inet->hdrincl.

Fixes: 8f659a03a0ba ("net: ipv4: fix for a race condition in raw_sendmsg")
Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:22:56 +02:00
Taras Chornyi
1cd63ccd59 net: ipv4: devinet: Fix crash when add/del multicast IP with autojoin
[ Upstream commit 690cc86321eb9bcee371710252742fb16fe96824 ]

When CONFIG_IP_MULTICAST is not set and multicast ip is added to the device
with autojoin flag or when multicast ip is deleted kernel will crash.

steps to reproduce:

ip addr add 224.0.0.0/32 dev eth0
ip addr del 224.0.0.0/32 dev eth0

or

ip addr add 224.0.0.0/32 dev eth0 autojoin

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000088
 pc : _raw_write_lock_irqsave+0x1e0/0x2ac
 lr : lock_sock_nested+0x1c/0x60
 Call trace:
  _raw_write_lock_irqsave+0x1e0/0x2ac
  lock_sock_nested+0x1c/0x60
  ip_mc_config.isra.28+0x50/0xe0
  inet_rtm_deladdr+0x1a8/0x1f0
  rtnetlink_rcv_msg+0x120/0x350
  netlink_rcv_skb+0x58/0x120
  rtnetlink_rcv+0x14/0x20
  netlink_unicast+0x1b8/0x270
  netlink_sendmsg+0x1a0/0x3b0
  ____sys_sendmsg+0x248/0x290
  ___sys_sendmsg+0x80/0xc0
  __sys_sendmsg+0x68/0xc0
  __arm64_sys_sendmsg+0x20/0x30
  el0_svc_common.constprop.2+0x88/0x150
  do_el0_svc+0x20/0x80
 el0_sync_handler+0x118/0x190
  el0_sync+0x140/0x180

Fixes: 93a714d6b53d ("multicast: Extend ip address command to enable multicast group join/leave on")
Signed-off-by: Taras Chornyi <taras.chornyi@plvision.eu>
Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 07:59:02 +02:00
William Dauchy
4f1640e3f1 net, ip_tunnel: fix interface lookup with no key
[ Upstream commit 25629fdaff2ff509dd0b3f5ff93d70a75e79e0a1 ]

when creating a new ipip interface with no local/remote configuration,
the lookup is done with TUNNEL_NO_KEY flag, making it impossible to
match the new interface (only possible match being fallback or metada
case interface); e.g: `ip link add tunl1 type ipip dev eth0`

To fix this case, adding a flag check before the key comparison so we
permit to match an interface with no local/remote config; it also avoids
breaking possible userland tools relying on TUNNEL_NO_KEY flag and
uninitialised key.

context being on my side, I'm creating an extra ipip interface attached
to the physical one, and moving it to a dedicated namespace.

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: William Dauchy <w.dauchy@criteo.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-13 10:32:51 +02:00
Qian Cai
32006be244 ipv4: fix a RCU-list lock in fib_triestat_seq_show
[ Upstream commit fbe4e0c1b298b4665ee6915266c9d6c5b934ef4a ]

fib_triestat_seq_show() calls hlist_for_each_entry_rcu(tb, head,
tb_hlist) without rcu_read_lock() will trigger a warning,

 net/ipv4/fib_trie.c:2579 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by proc01/115277:
  #0: c0000014507acf00 (&p->lock){+.+.}-{3:3}, at: seq_read+0x58/0x670

 Call Trace:
  dump_stack+0xf4/0x164 (unreliable)
  lockdep_rcu_suspicious+0x140/0x164
  fib_triestat_seq_show+0x750/0x880
  seq_read+0x1a0/0x670
  proc_reg_read+0x10c/0x1b0
  __vfs_read+0x3c/0x70
  vfs_read+0xac/0x170
  ksys_read+0x7c/0x140
  system_call+0x5c/0x68

Fix it by adding a pair of rcu_read_lock/unlock() and use
cond_resched_rcu() to avoid the situation where walking of a large
number of items  may prevent scheduling for a long time.

Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-13 10:32:51 +02:00
Nicolas Dichtel
0807f59465 vti[6]: fix packet tx through bpf_redirect() in XinY cases
commit f1ed10264ed6b66b9cd5e8461cffce69be482356 upstream.

I forgot the 4in6/6in4 cases in my previous patch. Let's fix them.

Fixes: 95224166a903 ("vti[6]: fix packet tx through bpf_redirect()")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02 17:20:34 +02:00
Sabrina Dubroca
14c137ce30 net: ipv4: don't let PMTU updates increase route MTU
[ Upstream commit 28d35bcdd3925e7293408cdb8aa5f2aac5f0d6e3 ]

When an MTU update with PMTU smaller than net.ipv4.route.min_pmtu is
received, we must clamp its value. However, we can receive a PMTU
exception with PMTU < old_mtu < ip_rt_min_pmtu, which would lead to an
increase in PMTU.

To fix this, take the smallest of the old MTU and ip_rt_min_pmtu.

Before this patch, in case of an update, the exception's MTU would
always change. Now, an exception can have only its lock flag updated,
but not the MTU, so we need to add a check on locking to the following
"is this exception getting updated, or close to expiring?" test.

Fixes: d52e5a7e7ca4 ("ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-02 17:20:31 +02:00
Matteo Croce
0bde22da65 ipv4: ensure rcu_read_lock() in cipso_v4_error()
commit 3e72dfdf8227b052393f71d820ec7599909dddc2 upstream.

Similarly to commit c543cb4a5f07 ("ipv4: ensure rcu_read_lock() in
ipv4_link_failure()"), __ip_options_compile() must be called under rcu
protection.

Fixes: 3da1ed7ac398 ("net: avoid use IPCB in cipso_v4_error")
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-20 09:07:58 +01:00
Eric Dumazet
6f1aea70c1 gre: fix uninit-value in __iptunnel_pull_header
[ Upstream commit 17c25cafd4d3e74c83dce56b158843b19c40b414 ]

syzbot found an interesting case of the kernel reading
an uninit-value [1]

Problem is in the handling of ETH_P_WCCP in gre_parse_header()

We look at the byte following GRE options to eventually decide
if the options are four bytes longer.

Use skb_header_pointer() to not pull bytes if we found
that no more bytes were needed.

All callers of gre_parse_header() are properly using pskb_may_pull()
anyway before proceeding to next header.

[1]
BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2303 [inline]
BUG: KMSAN: uninit-value in __iptunnel_pull_header+0x30c/0xbd0 net/ipv4/ip_tunnel_core.c:94
CPU: 1 PID: 11784 Comm: syz-executor940 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 pskb_may_pull include/linux/skbuff.h:2303 [inline]
 __iptunnel_pull_header+0x30c/0xbd0 net/ipv4/ip_tunnel_core.c:94
 iptunnel_pull_header include/net/ip_tunnels.h:411 [inline]
 gre_rcv+0x15e/0x19c0 net/ipv6/ip6_gre.c:606
 ip6_protocol_deliver_rcu+0x181b/0x22c0 net/ipv6/ip6_input.c:432
 ip6_input_finish net/ipv6/ip6_input.c:473 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip6_input net/ipv6/ip6_input.c:482 [inline]
 ip6_mc_input+0xdf2/0x1460 net/ipv6/ip6_input.c:576
 dst_input include/net/dst.h:442 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:306
 __netif_receive_skb_one_core net/core/dev.c:5198 [inline]
 __netif_receive_skb net/core/dev.c:5312 [inline]
 netif_receive_skb_internal net/core/dev.c:5402 [inline]
 netif_receive_skb+0x66b/0xf20 net/core/dev.c:5461
 tun_rx_batched include/linux/skbuff.h:4321 [inline]
 tun_get_user+0x6aef/0x6f60 drivers/net/tun.c:1997
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:2026
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:496
 vfs_write+0x44a/0x8f0 fs/read_write.c:558
 ksys_write+0x267/0x450 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __ia32_sys_write+0xdb/0x120 fs/read_write.c:620
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f62d99
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000fffedb2c EFLAGS: 00000217 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020002580
RDX: 0000000000000fca RSI: 0000000000000036 RDI: 0000000000000004
RBP: 0000000000008914 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
 slab_alloc_node mm/slub.c:2793 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1051 [inline]
 alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5766
 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2242
 tun_alloc_skb drivers/net/tun.c:1529 [inline]
 tun_get_user+0x10ae/0x6f60 drivers/net/tun.c:1843
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:2026
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:496
 vfs_write+0x44a/0x8f0 fs/read_write.c:558
 ksys_write+0x267/0x450 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __ia32_sys_write+0xdb/0x120 fs/read_write.c:620
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139

Fixes: 95f5c64c3c13 ("gre: Move utility functions to common headers")
Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-20 09:07:38 +01:00
Eric Dumazet
1f6f96b99d tcp: clear tp->segs_{in|out} in tcp_disconnect()
[ Upstream commit 784f8344de750a41344f4bbbebb8507a730fc99c ]

tp->segs_in and tp->segs_out need to be cleared in tcp_disconnect().

tcp_disconnect() is rarely used, but it is worth fixing it.

Fixes: 2efd055c53c0 ("tcp: add tcpi_segs_in and tcpi_segs_out to tcp_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Marcelo Ricardo Leitner <mleitner@redhat.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:30:59 -05:00
Eric Dumazet
5022fce17b tcp: clear tp->data_segs{in|out} in tcp_disconnect()
[ Upstream commit db7ffee6f3eb3683cdcaeddecc0a630a14546fe3 ]

tp->data_segs_in and tp->data_segs_out need to be cleared
in tcp_disconnect().

tcp_disconnect() is rarely used, but it is worth fixing it.

Fixes: a44d6eacdaf5 ("tcp: Add RFC4898 tcpEStatsPerfDataSegsOut/In")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:30:59 -05:00
Eric Dumazet
f5b6109359 tcp: clear tp->delivered in tcp_disconnect()
[ Upstream commit 2fbdd56251b5c62f96589f39eded277260de7267 ]

tp->delivered needs to be cleared in tcp_disconnect().

tcp_disconnect() is rarely used, but it is worth fixing it.

Fixes: ddf1af6fa00e ("tcp: new delivery accounting")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:30:59 -05:00
Eric Dumazet
b1e355a76f tcp: clear tp->total_retrans in tcp_disconnect()
[ Upstream commit c13c48c00a6bc1febc73902505bdec0967bd7095 ]

total_retrans needs to be cleared in tcp_disconnect().

tcp_disconnect() is rarely used, but it is worth fixing it.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:30:59 -05:00
Nicolas Dichtel
be914e0906 vti[6]: fix packet tx through bpf_redirect()
[ Upstream commit 95224166a9032ff5d08fca633d37113078ce7d01 ]

With an ebpf program that redirects packets through a vti[6] interface,
the packets are dropped because no dst is attached.

This could also be reproduced with an AF_PACKET socket, with the following
python script (vti1 is an ip_vti interface):

 import socket
 send_s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, 0)
 # scapy
 # p = IP(src='10.100.0.2', dst='10.200.0.1')/ICMP(type='echo-request')
 # raw(p)
 req = b'E\x00\x00\x1c\x00\x01\x00\x00@\x01e\xb2\nd\x00\x02\n\xc8\x00\x01\x08\x00\xf7\xff\x00\x00\x00\x00'
 send_s.sendto(req, ('vti1', 0x800, 0, 0))

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-05 13:05:51 +00:00
Wen Yang
57d3e48b76 tcp_bbr: improve arithmetic division in bbr_update_bw()
[ Upstream commit 5b2f1f3070b6447b76174ea8bfb7390dc6253ebd ]

do_div() does a 64-by-32 division. Use div64_long() instead of it
if the divisor is long, to avoid truncation to 32-bit.
And as a nice side effect also cleans up the function a bit.

Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29 10:24:37 +01:00
William Dauchy
6769626ba9 net, ip_tunnel: fix namespaces move
[ Upstream commit d0f418516022c32ecceaf4275423e5bd3f8743a9 ]

in the same manner as commit 690afc165bb3 ("net: ip6_gre: fix moving
ip6gre between namespaces"), fix namespace moving as it was broken since
commit 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.").
Indeed, the ip6_gre commit removed the local flag for collect_md
condition, so there is no reason to keep it for ip_gre/ip_tunnel.

this patch will fix both ip_tunnel and ip_gre modules.

Fixes: 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.")
Signed-off-by: William Dauchy <w.dauchy@criteo.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29 10:24:37 +01:00
Pengcheng Yang
3930b48a34 tcp: fix marked lost packets not being retransmitted
[ Upstream commit e176b1ba476cf36f723cfcc7a9e57f3cb47dec70 ]

When the packet pointed to by retransmit_skb_hint is unlinked by ACK,
retransmit_skb_hint will be set to NULL in tcp_clean_rtx_queue().
If packet loss is detected at this time, retransmit_skb_hint will be set
to point to the current packet loss in tcp_verify_retransmit_hint(),
then the packets that were previously marked lost but not retransmitted
due to the restriction of cwnd will be skipped and cannot be
retransmitted.

To fix this, when retransmit_skb_hint is NULL, retransmit_skb_hint can
be reset only after all marked lost packets are retransmitted
(retrans_out >= lost_out), otherwise we need to traverse from
tcp_rtx_queue_head in tcp_xmit_retransmit_queue().

Packetdrill to demonstrate:

// Disable RACK and set max_reordering to keep things simple
    0 `sysctl -q net.ipv4.tcp_recovery=0`
   +0 `sysctl -q net.ipv4.tcp_max_reordering=3`

// Establish a connection
   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

  +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
   +0 > S. 0:0(0) ack 1 <...>
 +.01 < . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

// Send 8 data segments
   +0 write(4, ..., 8000) = 8000
   +0 > P. 1:8001(8000) ack 1

// Enter recovery and 1:3001 is marked lost
 +.01 < . 1:1(0) ack 1 win 257 <sack 3001:4001,nop,nop>
   +0 < . 1:1(0) ack 1 win 257 <sack 5001:6001 3001:4001,nop,nop>
   +0 < . 1:1(0) ack 1 win 257 <sack 5001:7001 3001:4001,nop,nop>

// Retransmit 1:1001, now retransmit_skb_hint points to 1001:2001
   +0 > . 1:1001(1000) ack 1

// 1001:2001 was ACKed causing retransmit_skb_hint to be set to NULL
 +.01 < . 1:1(0) ack 2001 win 257 <sack 5001:8001 3001:4001,nop,nop>
// Now retransmit_skb_hint points to 4001:5001 which is now marked lost

// BUG: 2001:3001 was not retransmitted
   +0 > . 2001:3001(1000) ack 1

Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Tested-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:19:42 +01:00
Florian Westphal
2564ab9b0b netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct
commit 212e7f56605ef9688d0846db60c6c6ec06544095 upstream.

An earlier commit (1b789577f655060d98d20e,
"netfilter: arp_tables: init netns pointer in xt_tgchk_param struct")
fixed missing net initialization for arptables, but turns out it was
incomplete.  We can get a very similar struct net NULL deref during
error unwinding:

general protection fault: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:xt_rateest_put+0xa1/0x440 net/netfilter/xt_RATEEST.c:77
 xt_rateest_tg_destroy+0x72/0xa0 net/netfilter/xt_RATEEST.c:175
 cleanup_entry net/ipv4/netfilter/arp_tables.c:509 [inline]
 translate_table+0x11f4/0x1d80 net/ipv4/netfilter/arp_tables.c:587
 do_replace net/ipv4/netfilter/arp_tables.c:981 [inline]
 do_arpt_set_ctl+0x317/0x650 net/ipv4/netfilter/arp_tables.c:1461

Also init the netns pointer in xt_tgdtor_param struct.

Fixes: add67461240c1d ("netfilter: add struct net * to target parameters")
Reported-by: syzbot+91bdd8eece0f6629ec8b@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:19:41 +01:00
Florian Westphal
76c146cef2 netfilter: arp_tables: init netns pointer in xt_tgchk_param struct
commit 1b789577f655060d98d20ed0c6f9fbd469d6ba63 upstream.

We get crash when the targets checkentry function tries to make
use of the network namespace pointer for arptables.

When the net pointer got added back in 2010, only ip/ip6/ebtables were
changed to initialize it, so arptables has this set to NULL.

This isn't a problem for normal arptables because no existing
arptables target has a checkentry function that makes use of par->net.

However, direct users of the setsockopt interface can provide any
target they want as long as its registered for ARP or UNPSEC protocols.

syzkaller managed to send a semi-valid arptables rule for RATEEST target
which is enough to trigger NULL deref:

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
RIP: xt_rateest_tg_checkentry+0x11d/0xb40 net/netfilter/xt_RATEEST.c:109
[..]
 xt_check_target+0x283/0x690 net/netfilter/x_tables.c:1019
 check_target net/ipv4/netfilter/arp_tables.c:399 [inline]
 find_check_entry net/ipv4/netfilter/arp_tables.c:422 [inline]
 translate_table+0x1005/0x1d70 net/ipv4/netfilter/arp_tables.c:572
 do_replace net/ipv4/netfilter/arp_tables.c:977 [inline]
 do_arpt_set_ctl+0x310/0x640 net/ipv4/netfilter/arp_tables.c:1456

Fixes: add67461240c1d ("netfilter: add struct net * to target parameters")
Reported-by: syzbot+d7358a458d8a81aee898@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14 20:04:31 +01:00
Marcelo Ricardo Leitner
638b632dde tcp: minimize false-positives on TCP/GRO check
commit 0b9aefea860063bb39e36bd7fe6c7087fed0ba87 upstream.

Markus Trippelsdorf reported that after commit dcb17d22e1c2 ("tcp: warn
on bogus MSS and try to amend it") the kernel started logging the
warning for a NIC driver that doesn't even support GRO.

It was diagnosed that it was possibly caused on connections that were
using TCP Timestamps but some packets lacked the Timestamps option. As
we reduce rcv_mss when timestamps are used, the lack of them would cause
the packets to be bigger than expected, although this is a valid case.

As this warning is more as a hint, getting a clean-cut on the
threshold is probably not worth the execution time spent on it. This
patch thus alleviates the false-positives with 2 quick checks: by
accounting for the entire TCP option space and also checking against the
interface MTU if it's available.

These changes, specially the MTU one, might mask some real positives,
though if they are really happening, it's possible that sooner or later
it will be triggered anyway.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14 20:04:26 +01:00