10644 Commits

Author SHA1 Message Date
Wei Wang
164294d09c tcp: disable TFO blackhole logic by default
[ Upstream commit 213ad73d06073b197a02476db3a4998e219ddb06 ]

Multiple complaints have been raised from the TFO users on the internet
stating that the TFO blackhole logic is too aggressive and gets falsely
triggered too often.
(e.g. https://blog.apnic.net/2021/07/05/tcp-fast-open-not-so-fast/)
Considering that most middleboxes no longer drop TFO packets, we decide
to disable the blackhole logic by setting
/proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_set to 0 by default.

Fixes: cf1ef3f0719b4 ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:41 +02:00
Eric Dumazet
41a839437a net/tcp_fastopen: fix data races around tfo_active_disable_stamp
[ Upstream commit 6f20c8adb1813467ea52c1296d52c4e95978cb2f ]

tfo_active_disable_stamp is read and written locklessly.
We need to annotate these accesses appropriately.

Then, we need to perform the atomic_inc(tfo_active_disable_times)
after the timestamp has been updated, and thus add barriers
to make sure tcp_fastopen_active_should_disable() wont read
a stale timestamp.

Fixes: cf1ef3f0719b ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:40 +02:00
Jakub Sitnicki
3b5b0afd8d bpf, sockmap, udp: sk_prot needs inuse_idx set for proc stats
[ Upstream commit 54ea2f49fd9400dd698c25450be3352b5613b3b4 ]

The proc socket stats use sk_prot->inuse_idx value to record inuse sock
stats. We currently do not set this correctly from sockmap side. The
result is reading sock stats '/proc/net/sockstat' gives incorrect values.
The socket counter is incremented correctly, but because we don't set the
counter correctly when we replace sk_prot we may omit the decrement.

To get the correct inuse_idx value move the core_initcall that initializes
the UDP proto handlers to late_initcall. This way it is initialized after
UDP has the chance to assign the inuse_idx value from the register protocol
handler.

Fixes: edc6741cc660 ("bpf: Add sockmap hooks for UDP sockets")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210714154750.528206-1-jakub@cloudflare.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:37 +02:00
John Fastabend
c260442431 bpf, sockmap, tcp: sk_prot needs inuse_idx set for proc stats
[ Upstream commit 228a4a7ba8e99bb9ef980b62f71e3be33f4aae69 ]

The proc socket stats use sk_prot->inuse_idx value to record inuse sock
stats. We currently do not set this correctly from sockmap side. The
result is reading sock stats '/proc/net/sockstat' gives incorrect values.
The socket counter is incremented correctly, but because we don't set the
counter correctly when we replace sk_prot we may omit the decrement.

To get the correct inuse_idx value move the core_initcall that initializes
the TCP proto handlers to late_initcall. This way it is initialized after
TCP has the chance to assign the inuse_idx value from the register protocol
handler.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/bpf/20210712195546.423990-3-john.fastabend@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:37 +02:00
Eric Dumazet
6cd9bd2a2d udp: annotate data races around unix_sk(sk)->gso_size
commit 18a419bad63b7f68a1979e28459782518e7b6bbe upstream.

Accesses to unix_sk(sk)->gso_size are lockless.
Add READ_ONCE()/WRITE_ONCE() around them.

BUG: KCSAN: data-race in udp_lib_setsockopt / udpv6_sendmsg

write to 0xffff88812d78f47c of 2 bytes by task 10849 on cpu 1:
 udp_lib_setsockopt+0x3b3/0x710 net/ipv4/udp.c:2696
 udpv6_setsockopt+0x63/0x90 net/ipv6/udp.c:1630
 sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3265
 __sys_setsockopt+0x18f/0x200 net/socket.c:2104
 __do_sys_setsockopt net/socket.c:2115 [inline]
 __se_sys_setsockopt net/socket.c:2112 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2112
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812d78f47c of 2 bytes by task 10852 on cpu 0:
 udpv6_sendmsg+0x161/0x16b0 net/ipv6/udp.c:1299
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2337
 ___sys_sendmsg net/socket.c:2391 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2477
 __do_sys_sendmmsg net/socket.c:2506 [inline]
 __se_sys_sendmmsg net/socket.c:2503 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2503
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0x0005

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10852 Comm: syz-executor.0 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@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>
2021-07-25 14:36:22 +02:00
Talal Ahmad
638632997c tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy path
commit 358ed624207012f03318235017ac6fb41f8af592 upstream.

sk_wmem_schedule makes sure that sk_forward_alloc has enough
bytes for charging that is going to be done by sk_mem_charge.

In the transmit zerocopy path, there is sk_mem_charge but there was
no call to sk_wmem_schedule. This change adds that call.

Without this call to sk_wmem_schedule, sk_forward_alloc can go
negetive which is a bug because sk_forward_alloc is a per-socket
space that has been forward charged so this can't be negative.

Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Talal Ahmad <talalahmad@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@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>
2021-07-25 14:36:21 +02:00
Eric Dumazet
2fee3cf4c9 ipv6: tcp: drop silly ICMPv6 packet too big messages
commit c7bb4b89033b764eb07db4e060548a6311d801ee upstream.

While TCP stack scales reasonably well, there is still one part that
can be used to DDOS it.

IPv6 Packet too big messages have to lookup/insert a new route,
and if abused by attackers, can easily put hosts under high stress,
with many cpus contending on a spinlock while one is stuck in fib6_run_gc()

ip6_protocol_deliver_rcu()
 icmpv6_rcv()
  icmpv6_notify()
   tcp_v6_err()
    tcp_v6_mtu_reduced()
     inet6_csk_update_pmtu()
      ip6_rt_update_pmtu()
       __ip6_rt_update_pmtu()
        ip6_rt_cache_alloc()
         ip6_dst_alloc()
          dst_alloc()
           ip6_dst_gc()
            fib6_run_gc()
             spin_lock_bh() ...

Some of our servers have been hit by malicious ICMPv6 packets
trying to _increase_ the MTU/MSS of TCP flows.

We believe these ICMPv6 packets are a result of a bug in one ISP stack,
since they were blindly sent back for _every_ (small) packet sent to them.

These packets are for one TCP flow:
09:24:36.266491 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.266509 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316688 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316704 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.608151 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240

TCP stack can filter some silly requests :

1) MTU below IPV6_MIN_MTU can be filtered early in tcp_v6_err()
2) tcp_v6_mtu_reduced() can drop requests trying to increase current MSS.

This tests happen before the IPv6 routing stack is entered, thus
removing the potential contention and route exhaustion.

Note that IPv6 stack was performing these checks, but too late
(ie : after the route has been added, and after the potential
garbage collect war)

v2: fix typo caught by Martin, thanks !
v3: exports tcp_mtu_to_mss(), caught by David, thanks !

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:36:21 +02:00
Nguyen Dinh Phi
ad4ba34049 tcp: fix tcp_init_transfer() to not reset icsk_ca_initialized
commit be5d1b61a2ad28c7e57fe8bfa277373e8ecffcdc upstream.

This commit fixes a bug (found by syzkaller) that could cause spurious
double-initializations for congestion control modules, which could cause
memory leaks or other problems for congestion control modules (like CDG)
that allocate memory in their init functions.

The buggy scenario constructed by syzkaller was something like:

(1) create a TCP socket
(2) initiate a TFO connect via sendto()
(3) while socket is in TCP_SYN_SENT, call setsockopt(TCP_CONGESTION),
    which calls:
       tcp_set_congestion_control() ->
         tcp_reinit_congestion_control() ->
           tcp_init_congestion_control()
(4) receive ACK, connection is established, call tcp_init_transfer(),
    set icsk_ca_initialized=0 (without first calling cc->release()),
    call tcp_init_congestion_control() again.

Note that in this sequence tcp_init_congestion_control() is called
twice without a cc->release() call in between. Thus, for CC modules
that allocate memory in their init() function, e.g, CDG, a memory leak
may occur. The syzkaller tool managed to find a reproducer that
triggered such a leak in CDG.

The bug was introduced when that commit 8919a9b31eb4 ("tcp: Only init
congestion control if not initialized already")
introduced icsk_ca_initialized and set icsk_ca_initialized to 0 in
tcp_init_transfer(), missing the possibility for a sequence like the
one above, where a process could call setsockopt(TCP_CONGESTION) in
state TCP_SYN_SENT (i.e. after the connect() or TFO open sendmsg()),
which would call tcp_init_congestion_control(). It did not intend to
reset any initialization that the user had already explicitly made;
it just missed the possibility of that particular sequence (which
syzkaller managed to find).

Fixes: 8919a9b31eb4 ("tcp: Only init congestion control if not initialized already")
Reported-by: syzbot+f1e24a0594d4e3a895d3@syzkaller.appspotmail.com
Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.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>
2021-07-25 14:36:21 +02:00
Eric Dumazet
d60f07bcb7 tcp: annotate data races around tp->mtu_info
commit 561022acb1ce62e50f7a8258687a21b84282a4cb upstream.

While tp->mtu_info is read while socket is owned, the write
sides happen from err handlers (tcp_v[46]_mtu_reduced)
which only own the socket spinlock.

Fixes: 563d34d05786 ("tcp: dont drop MTU reduction indications")
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>
2021-07-25 14:36:21 +02:00
Hangbin Liu
88ff9ec9c6 net: ip_tunnel: fix mtu calculation for ETHER tunnel devices
commit 9992a078b1771da354ac1f9737e1e639b687caa2 upstream.

Commit 28e104d00281 ("net: ip_tunnel: fix mtu calculation") removed
dev->hard_header_len subtraction when calculate MTU for tunnel devices
as there is an overhead for device that has header_ops.

But there are ETHER tunnel devices, like gre_tap or erspan, which don't
have header_ops but set dev->hard_header_len during setup. This makes
pkts greater than (MTU - ETH_HLEN) could not be xmited. Fix it by
subtracting the ETHER tunnel devices' dev->hard_header_len for MTU
calculation.

Fixes: 28e104d00281 ("net: ip_tunnel: fix mtu calculation")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:36:19 +02:00
Jakub Kicinski
a8585fdf42 net: ip: avoid OOM kills with large UDP sends over loopback
[ Upstream commit 6d123b81ac615072a8525c13c6c41b695270a15d ]

Dave observed number of machines hitting OOM on the UDP send
path. The workload seems to be sending large UDP packets over
loopback. Since loopback has MTU of 64k kernel will try to
allocate an skb with up to 64k of head space. This has a good
chance of failing under memory pressure. What's worse if
the message length is <32k the allocation may trigger an
OOM killer.

This is entirely avoidable, we can use an skb with page frags.

af_unix solves a similar problem by limiting the head
length to SKB_MAX_ALLOC. This seems like a good and simple
approach. It means that UDP messages > 16kB will now
use fragments if underlying device supports SG, if extra
allocator pressure causes regressions in real workloads
we can switch to trying the large allocation first and
falling back.

v4: pre-calculate all the additions to alloclen so
    we can be sure it won't go over order-2

Reported-by: Dave Jones <dsj@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 09:44:53 +02:00
Yuchung Cheng
f9c67c179e net: tcp better handling of reordering then loss cases
[ Upstream commit a29cb6914681a55667436a9eb7a42e28da8cf387 ]

This patch aims to improve the situation when reordering and loss are
ocurring in the same flight of packets.

Previously the reordering would first induce a spurious recovery, then
the subsequent ACK may undo the cwnd (based on the timestamps e.g.).
However the current loss recovery does not proceed to invoke
RACK to install a reordering timer. If some packets are also lost, this
may lead to a long RTO-based recovery. An example is
https://groups.google.com/g/bbr-dev/c/OFHADvJbTEI

The solution is to after reverting the recovery, always invoke RACK
to either mount the RACK timer to fast retransmit after the reordering
window, or restarts the recovery if new loss is identified. Hence
it is possible the sender may go from Recovery to Disorder/Open to
Recovery again in one ACK.

Reported-by: mingkun bian <bianmingkun@gmail.com>
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: Sasha Levin <sashal@kernel.org>
2021-07-19 09:44:45 +02:00
Vadim Fedorenko
4476568069 net: lwtunnel: handle MTU calculation in forwading
[ Upstream commit fade56410c22cacafb1be9f911a0afd3701d8366 ]

Commit 14972cbd34ff ("net: lwtunnel: Handle fragmentation") moved
fragmentation logic away from lwtunnel by carry encap headroom and
use it in output MTU calculation. But the forwarding part was not
covered and created difference in MTU for output and forwarding and
further to silent drops on ipv4 forwarding path. Fix it by taking
into account lwtunnel encap headroom.

The same commit also introduced difference in how to treat RTAX_MTU
in IPv4 and IPv6 where latter explicitly removes lwtunnel encap
headroom from route MTU. Make IPv4 version do the same.

Fixes: 14972cbd34ff ("net: lwtunnel: Handle fragmentation")
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:32 +02:00
Miao Wang
6610d5a73b net/ipv4: swap flow ports when validating source
[ Upstream commit c69f114d09891adfa3e301a35d9e872b8b7b5a50 ]

When doing source address validation, the flowi4 struct used for
fib_lookup should be in the reverse direction to the given skb.
fl4_dport and fl4_sport returned by fib4_rules_early_flow_dissect
should thus be swapped.

Fixes: 5a847a6e1477 ("net/ipv4: Initialize proto and ports in flow struct")
Signed-off-by: Miao Wang <shankerwangmiao@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:25 +02:00
Sabrina Dubroca
1de9425286 xfrm: xfrm_state_mtu should return at least 1280 for ipv6
[ Upstream commit b515d2637276a3810d6595e10ab02c13bfd0b63a ]

Jianwen reported that IPv6 Interoperability tests are failing in an
IPsec case where one of the links between the IPsec peers has an MTU
of 1280. The peer generates a packet larger than this MTU, the router
replies with a "Packet too big" message indicating an MTU of 1280.
When the peer tries to send another large packet, xfrm_state_mtu
returns 1280 - ipsec_overhead, which causes ip6_setup_cork to fail
with EINVAL.

We can fix this by forcing xfrm_state_mtu to return IPV6_MIN_MTU when
IPv6 is used. After going through IPsec, the packet will then be
fragmented to obey the actual network's PMTU, just before leaving the
host.

Currently, TFC padding is capped to PMTU - overhead to avoid
fragementation: after padding and encapsulation, we still fit within
the PMTU. That behavior is preserved in this patch.

Fixes: 91657eafb64b ("xfrm: take net hdr len into account for esp payload size calculation")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:14 +02:00
Zheng Yongjun
61b132f67c ping: Check return value of function 'ping_queue_rcv_skb'
[ Upstream commit 9d44fa3e50cc91691896934d106c86e4027e61ca ]

Function 'ping_queue_rcv_skb' not always return success, which will
also return fail. If not check the wrong return value of it, lead to function
`ping_rcv` return success.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:47:20 -04:00
Eric Dumazet
08c389de6d inet: annotate data race in inet_send_prepare() and inet_dgram_connect()
[ Upstream commit dcd01eeac14486b56a790f5cce9b823440ba5b34 ]

Both functions are known to be racy when reading inet_num
as we do not want to grab locks for the common case the socket
has been bound already. The race is resolved in inet_autobind()
by reading again inet_num under the socket lock.

syzbot reported:
BUG: KCSAN: data-race in inet_send_prepare / udp_lib_get_port

write to 0xffff88812cba150e of 2 bytes by task 24135 on cpu 0:
 udp_lib_get_port+0x4b2/0xe20 net/ipv4/udp.c:308
 udp_v6_get_port+0x5e/0x70 net/ipv6/udp.c:89
 inet_autobind net/ipv4/af_inet.c:183 [inline]
 inet_send_prepare+0xd0/0x210 net/ipv4/af_inet.c:807
 inet6_sendmsg+0x29/0x80 net/ipv6/af_inet6.c:639
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812cba150e of 2 bytes by task 24132 on cpu 1:
 inet_send_prepare+0x21/0x210 net/ipv4/af_inet.c:806
 inet6_sendmsg+0x29/0x80 net/ipv6/af_inet6.c:639
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0x9db4

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24132 Comm: syz-executor.2 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

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: Sasha Levin <sashal@kernel.org>
2021-06-30 08:47:20 -04:00
Zheng Yongjun
fedc4d4f54 net: ipv4: Remove unneed BUG() function
[ Upstream commit 5ac6b198d7e312bd10ebe7d58c64690dc59cc49a ]

When 'nla_parse_nested_deprecated' failed, it's no need to
BUG() here, return -EINVAL is ok.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:47:20 -04:00
Toke Høiland-Jørgensen
8c0c2d97ad icmp: don't send out ICMP messages with a source address of 0.0.0.0
[ Upstream commit 321827477360934dc040e9d3c626bf1de6c3ab3c ]

When constructing ICMP response messages, the kernel will try to pick a
suitable source address for the outgoing packet. However, if no IPv4
addresses are configured on the system at all, this will fail and we end up
producing an ICMP message with a source address of 0.0.0.0. This can happen
on a box routing IPv4 traffic via v6 nexthops, for instance.

Since 0.0.0.0 is not generally routable on the internet, there's a good
chance that such ICMP messages will never make it back to the sender of the
original packet that the ICMP message was sent in response to. This, in
turn, can create connectivity and PMTUd problems for senders. Fortunately,
RFC7600 reserves a dummy address to be used as a source for ICMP
messages (192.0.0.8/32), so let's teach the kernel to substitute that
address as a last resort if the regular source address selection procedure
fails.

Below is a quick example reproducing this issue with network namespaces:

ip netns add ns0
ip l add type veth peer netns ns0
ip l set dev veth0 up
ip a add 10.0.0.1/24 dev veth0
ip a add fc00:dead:cafe:42::1/64 dev veth0
ip r add 10.1.0.0/24 via inet6 fc00:dead:cafe:42::2
ip -n ns0 l set dev veth0 up
ip -n ns0 a add fc00:dead:cafe:42::2/64 dev veth0
ip -n ns0 r add 10.0.0.0/24 via inet6 fc00:dead:cafe:42::1
ip netns exec ns0 sysctl -w net.ipv4.icmp_ratelimit=0
ip netns exec ns0 sysctl -w net.ipv4.ip_forward=1
tcpdump -tpni veth0 -c 2 icmp &
ping -w 1 10.1.0.1 > /dev/null
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on veth0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
IP 10.0.0.1 > 10.1.0.1: ICMP echo request, id 29, seq 1, length 64
IP 0.0.0.0 > 10.0.0.1: ICMP net 10.1.0.1 unreachable, length 92
2 packets captured
2 packets received by filter
0 packets dropped by kernel

With this patch the above capture changes to:
IP 10.0.0.1 > 10.1.0.1: ICMP echo request, id 31127, seq 1, length 64
IP 192.0.0.8 > 10.0.0.1: ICMP net 10.1.0.1 unreachable, length 92

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Juliusz Chroboczek <jch@irif.fr>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:47 +02:00
Chengyang Fan
ac31cc837c net: ipv4: fix memory leak in ip_mc_add1_src
[ Upstream commit d8e2973029b8b2ce477b564824431f3385c77083 ]

BUG: memory leak
unreferenced object 0xffff888101bc4c00 (size 32):
  comm "syz-executor527", pid 360, jiffies 4294807421 (age 19.329s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
    01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................
  backtrace:
    [<00000000f17c5244>] kmalloc include/linux/slab.h:558 [inline]
    [<00000000f17c5244>] kzalloc include/linux/slab.h:688 [inline]
    [<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [inline]
    [<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095
    [<000000001cb99709>] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416
    [<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [inline]
    [<0000000052cf19ed>] ip_setsockopt+0x114b/0x30c0 net/ipv4/ip_sockglue.c:1423
    [<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857
    [<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117
    [<00000000bdb993a8>] __do_sys_setsockopt net/socket.c:2128 [inline]
    [<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [inline]
    [<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125
    [<000000006a1ffdbd>] do_syscall_64+0x40/0x80 arch/x86/entry/common.c:47
    [<00000000b11467c4>] entry_SYSCALL_64_after_hwframe+0x44/0xae

In commit 24803f38a5c0 ("igmp: do not remove igmp souce list info when set
link down"), the ip_mc_clear_src() in ip_mc_destroy_dev() was removed,
because it was also called in igmpv3_clear_delrec().

Rough callgraph:

inetdev_destroy
-> ip_mc_destroy_dev
     -> igmpv3_clear_delrec
        -> ip_mc_clear_src
-> RCU_INIT_POINTER(dev->ip_ptr, NULL)

However, ip_mc_clear_src() called in igmpv3_clear_delrec() doesn't
release in_dev->mc_list->sources. And RCU_INIT_POINTER() assigns the
NULL to dev->ip_ptr. As a result, in_dev cannot be obtained through
inetdev_by_index() and then in_dev->mc_list->sources cannot be released
by ip_mc_del1_src() in the sock_close. Rough call sequence goes like:

sock_close
-> __sock_release
   -> inet_release
      -> ip_mc_drop_socket
         -> inetdev_by_index
         -> ip_mc_leave_src
            -> ip_mc_del_src
               -> ip_mc_del1_src

So we still need to call ip_mc_clear_src() in ip_mc_destroy_dev() to free
in_dev->mc_list->sources.

Fixes: 24803f38a5c0 ("igmp: do not remove igmp souce list info ...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Chengyang Fan <cy.fan@huawei.com>
Acked-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:46 +02:00
David Ahern
0239c439ce ipv4: Fix device used for dst_alloc with local routes
[ Upstream commit b87b04f5019e821c8c6c7761f258402e43500a1f ]

Oliver reported a use case where deleting a VRF device can hang
waiting for the refcnt to drop to 0. The root cause is that the dst
is allocated against the VRF device but cached on the loopback
device.

The use case (added to the selftests) has an implicit VRF crossing
due to the ordering of the FIB rules (lookup local is before the
l3mdev rule, but the problem occurs even if the FIB rules are
re-ordered with local after l3mdev because the VRF table does not
have a default route to terminate the lookup). The end result is
is that the FIB lookup returns the loopback device as the nexthop,
but the ingress device is in a VRF. The mismatch causes the dst
alloc against the VRF device but then cached on the loopback.

The fix is to bring the trick used for IPv6 (see ip6_rt_get_dev_rcu):
pick the dst alloc device based the fib lookup result but with checks
that the result has a nexthop device (e.g., not an unreachable or
prohibit entry).

Fixes: f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant")
Reported-by: Oliver Herms <oliver.peter.herms@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:45 +02:00
Paolo Abeni
8729ec8a22 udp: fix race between close() and udp_abort()
[ Upstream commit a8b897c7bcd47f4147d066e22cc01d1026d7640e ]

Kaustubh reported and diagnosed a panic in udp_lib_lookup().
The root cause is udp_abort() racing with close(). Both
racing functions acquire the socket lock, but udp{v6}_destroy_sock()
release it before performing destructive actions.

We can't easily extend the socket lock scope to avoid the race,
instead use the SOCK_DEAD flag to prevent udp_abort from doing
any action when the critical race happens.

Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>
Fixes: 5d77dca82839 ("net: diag: support SOCK_DESTROY for UDP sockets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:42 +02:00
Nanyong Sun
deeeb65c6e net: ipv4: fix memory leak in netlbl_cipsov4_add_std
[ Upstream commit d612c3f3fae221e7ea736d196581c2217304bbbc ]

Reported by syzkaller:
BUG: memory leak
unreferenced object 0xffff888105df7000 (size 64):
comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline]
[<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline]
[<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline]
[<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416
[<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739
[<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
[<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800
[<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
[<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
[<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
[<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
[<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
[<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline]
[<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674
[<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
[<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
[<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
[<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
[<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae

The memory of doi_def->map.std pointing is allocated in
netlbl_cipsov4_add_std, but no place has freed it. It should be
freed in cipso_v4_doi_free which frees the cipso DOI resource.

Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:42:41 +02:00
Josh Triplett
ecd26536ec net: ipconfig: Don't override command-line hostnames or domains
[ Upstream commit b508d5fb69c2211a1b860fc058aafbefc3b3c3cd ]

If the user specifies a hostname or domain name as part of the ip=
command-line option, preserve it and don't overwrite it with one
supplied by DHCP/BOOTP.

For instance, ip=::::myhostname::dhcp will use "myhostname" rather than
ignoring and overwriting it.

Fix the comment on ic_bootp_string that suggests it only copies a string
"if not already set"; it doesn't have any such logic.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-18 10:00:05 +02:00
Jonathon Reinhart
6c1ea8bee7 net: Only allow init netns to set default tcp cong to a restricted algo
commit 8d432592f30fcc34ef5a10aac4887b4897884493 upstream.

tcp_set_default_congestion_control() is netns-safe in that it writes
to &net->ipv4.tcp_congestion_control, but it also sets
ca->flags |= TCP_CONG_NON_RESTRICTED which is not namespaced.
This has the unintended side-effect of changing the global
net.ipv4.tcp_allowed_congestion_control sysctl, despite the fact that it
is read-only: 97684f0970f6 ("net: Make tcp_allowed_congestion_control
readonly in non-init netns")

Resolve this netns "leak" by only allowing the init netns to set the
default algorithm to one that is restricted. This restriction could be
removed if tcp_allowed_congestion_control were namespace-ified in the
future.

This bug was uncovered with
https://github.com/JonathonReinhart/linux-netns-sysctl-verify

Fixes: 6670e1524477 ("tcp: Namespace-ify sysctl_tcp_default_congestion_control")
Signed-off-by: Jonathon Reinhart <jonathon.reinhart@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14 09:50:46 +02:00
Paolo Abeni
4877c4a523 udp: never accept GSO_FRAGLIST packets
[ Upstream commit 78352f73dc5047f3f744764cc45912498c52f3c9 ]

Currently the UDP protocol delivers GSO_FRAGLIST packets to
the sockets without the expected segmentation.

This change addresses the issue introducing and maintaining
a couple of new fields to explicitly accept SKB_GSO_UDP_L4
or GSO_FRAGLIST packets. Additionally updates  udp_unexpected_gso()
accordingly.

UDP sockets enabling UDP_GRO stil keep accept_udp_fraglist
zeroed.

v1 -> v2:
 - use 2 bits instead of a whole GSO bitmask (Willem)

Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:31 +02:00
Eric Dumazet
a273c27d72 inet: use bigger hash table for IP ID generation
[ Upstream commit aa6dd211e4b1dde9d5dc25d699d35f789ae7eeba ]

In commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
I used a very small hash table that could be abused
by patient attackers to reveal sensitive information.

Switch to a dynamic sizing, depending on RAM size.

Typical big hosts will now use 128x more storage (2 MB)
to get a similar increase in security and reduction
of hash collisions.

As a bonus, use of alloc_large_system_hash() spreads
allocated memory among all NUMA nodes.

Fixes: 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:30 +02:00
Jonathon Reinhart
35d7491e2f net: Make tcp_allowed_congestion_control readonly in non-init netns
commit 97684f0970f6e112926de631fdd98d9693c7e5c1 upstream.

Currently, tcp_allowed_congestion_control is global and writable;
writing to it in any net namespace will leak into all other net
namespaces.

tcp_available_congestion_control and tcp_allowed_congestion_control are
the only sysctls in ipv4_net_table (the per-netns sysctl table) with a
NULL data pointer; their handlers (proc_tcp_available_congestion_control
and proc_allowed_congestion_control) have no other way of referencing a
struct net. Thus, they operate globally.

Because ipv4_net_table does not use designated initializers, there is no
easy way to fix up this one "bad" table entry. However, the data pointer
updating logic shouldn't be applied to NULL pointers anyway, so we
instead force these entries to be read-only.

These sysctls used to exist in ipv4_table (init-net only), but they were
moved to the per-net ipv4_net_table, presumably without realizing that
tcp_allowed_congestion_control was writable and thus introduced a leak.

Because the intent of that commit was only to know (i.e. read) "which
congestion algorithms are available or allowed", this read-only solution
should be sufficient.

The logic added in recent commit
31c4d2f160eb: ("net: Ensure net namespace isolation of sysctls")
does not and cannot check for NULL data pointers, because
other table entries (e.g. /proc/sys/net/netfilter/nf_log/) have
.data=NULL but use other methods (.extra2) to access the struct net.

Fixes: 9cb8e048e5d9 ("net/ipv4/sysctl: show tcp_{allowed, available}_congestion_control in non-initial netns")
Signed-off-by: Jonathon Reinhart <jonathon.reinhart@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21 13:00:57 +02:00
Florian Westphal
7824d5a993 netfilter: arp_tables: add pre_exit hook for table unregister
commit d163a925ebbc6eb5b562b0f1d72c7e817aa75c40 upstream.

Same problem that also existed in iptables/ip(6)tables, when
arptable_filter is removed there is no longer a wait period before the
table/ruleset is free'd.

Unregister the hook in pre_exit, then remove the table in the exit
function.
This used to work correctly because the old nf_hook_unregister API
did unconditional synchronize_net.

The per-net hook unregister function uses call_rcu instead.

Fixes: b9e69e127397 ("netfilter: xtables: don't hook tables by default")
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>
2021-04-21 13:00:56 +02:00
Florian Westphal
1f3b9000cb netfilter: x_tables: fix compat match/target pad out-of-bound write
commit b29c457a6511435960115c0f548c4360d5f4801d upstream.

xt_compat_match/target_from_user doesn't check that zeroing the area
to start of next rule won't write past end of allocated ruleset blob.

Remove this code and zero the entire blob beforehand.

Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com
Reported-by: Andy Nguyen <theflow@google.com>
Fixes: 9fa492cdc160c ("[NETFILTER]: x_tables: simplify compat API")
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>
2021-04-16 11:43:21 +02:00
Norman Maurer
24bbfe89b1 net: udp: Add support for getsockopt(..., ..., UDP_GRO, ..., ...);
[ Upstream commit 98184612aca0a9ee42b8eb0262a49900ee9eef0d ]

Support for UDP_GRO was added in the past but the implementation for
getsockopt was missed which did lead to an error when we tried to
retrieve the setting for UDP_GRO. This patch adds the missing switch
case for UDP_GRO

Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.")
Signed-off-by: Norman Maurer <norman_maurer@apple.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:09 +02:00
Steffen Klassert
58f8f10740 xfrm: Provide private skb extensions for segmented and hw offloaded ESP packets
[ Upstream commit c7dbf4c08868d9db89b8bfe8f8245ca61b01ed2f ]

Commit 94579ac3f6d0 ("xfrm: Fix double ESP trailer insertion in IPsec
crypto offload.") added a XFRM_XMIT flag to avoid duplicate ESP trailer
insertion on HW offload. This flag is set on the secpath that is shared
amongst segments. This lead to a situation where some segments are
not transformed correctly when segmentation happens at layer 3.

Fix this by using private skb extensions for segmented and hw offloaded
ESP packets.

Fixes: 94579ac3f6d0 ("xfrm: Fix double ESP trailer insertion in IPsec crypto offload.")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:07 +02:00
Xin Long
ef4ddd1d6d esp: delete NETIF_F_SCTP_CRC bit from features for esp offload
[ Upstream commit 154deab6a3ba47792936edf77f2f13a1cbc4351d ]

Now in esp4/6_gso_segment(), before calling inner proto .gso_segment,
NETIF_F_CSUM_MASK bits are deleted, as HW won't be able to do the
csum for inner proto due to the packet encrypted already.

So the UDP/TCP packet has to do the checksum on its own .gso_segment.
But SCTP is using CRC checksum, and for that NETIF_F_SCTP_CRC should
be deleted to make SCTP do the csum in own .gso_segment as well.

In Xiumei's testing with SCTP over IPsec/veth, the packets are kept
dropping due to the wrong CRC checksum.

Reported-by: Xiumei Mu <xmu@redhat.com>
Fixes: 7862b4058b9f ("esp: Add gso handlers for esp4 and esp6")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:06 +02:00
Evan Nimmo
c7a175a24b xfrm: Use actual socket sk instead of skb socket for xfrm_output_resume
[ Upstream commit 9ab1265d52314fce1b51e8665ea6dbc9ac1a027c ]

A situation can occur where the interface bound to the sk is different
to the interface bound to the sk attached to the skb. The interface
bound to the sk is the correct one however this information is lost inside
xfrm_output2 and instead the sk on the skb is used in xfrm_output_resume
instead. This assumes that the sk bound interface and the bound interface
attached to the sk within the skb are the same which can lead to lookup
failures inside ip_route_me_harder resulting in the packet being dropped.

We have an l2tp v3 tunnel with ipsec protection. The tunnel is in the
global VRF however we have an encapsulated dot1q tunnel interface that
is within a different VRF. We also have a mangle rule that marks the
packets causing them to be processed inside ip_route_me_harder.

Prior to commit 31c70d5956fc ("l2tp: keep original skb ownership") this
worked fine as the sk attached to the skb was changed from the dot1q
encapsulated interface to the sk for the tunnel which meant the interface
bound to the sk and the interface bound to the skb were identical.
Commit 46d6c5ae953c ("netfilter: use actual socket sk rather than skb sk
when routing harder") fixed some of these issues however a similar
problem existed in the xfrm code.

Fixes: 31c70d5956fc ("l2tp: keep original skb ownership")
Signed-off-by: Evan Nimmo <evan.nimmo@alliedtelesis.co.nz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:05 +02:00
Mark Tomlinson
c33f918758 Revert "netfilter: x_tables: Update remaining dereference to RCU"
[ Upstream commit abe7034b9a8d57737e80cc16d60ed3666990bdbf ]

This reverts commit 443d6e86f821a165fae3fc3fc13086d27ac140b1.

This (and the following) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:06 +02:00
Mark Tomlinson
520be4d1af Revert "netfilter: x_tables: Switch synchronization to RCU"
[ Upstream commit d3d40f237480abf3268956daf18cdc56edd32834 ]

This reverts commit cc00bcaa589914096edef7fb87ca5cee4a166b5c.

This (and the preceding) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Prior to using RCU a script calling "iptables" approx. 200 times was
taking 1.16s. With RCU this increased to 11.59s.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:05 +02:00
Daniel Borkmann
0a245acbce net: Consolidate common blackhole dst ops
[ Upstream commit c4c877b2732466b4c63217baad05c96f775912c7 ]

Move generic blackhole dst ops to the core and use them from both
ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No
functional change otherwise. We need these also in other locations
and having to define them over and over again is not great.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:05 +02:00
Alexander Ovechkin
63f2a9bd31 tcp: relookup sock for RST+ACK packets handled by obsolete req sock
[ Upstream commit 7233da86697efef41288f8b713c10c2499cffe85 ]

Currently tcp_check_req can be called with obsolete req socket for which big
socket have been already created (because of CPU race or early demux
assigning req socket to multiple packets in gro batch).

Commit e0f9759f530bf789e984 ("tcp: try to keep packet if SYN_RCV race
is lost") added retry in case when tcp_check_req is called for PSH|ACK packet.
But if client sends RST+ACK immediatly after connection being
established (it is performing healthcheck, for example) retry does not
occur. In that case tcp_check_req tries to close req socket,
leaving big socket active.

Fixes: e0f9759f530 ("tcp: try to keep packet if SYN_RCV race is lost")
Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru>
Reported-by: Oleg Senin <olegsenin@yandex-team.ru>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:59 +02:00
Paul Moore
85178d76fe cipso,calipso: resolve a number of problems with the DOI refcounts
commit ad5d07f4a9cd671233ae20983848874731102c08 upstream.

The current CIPSO and CALIPSO refcounting scheme for the DOI
definitions is a bit flawed in that we:

1. Don't correctly match gets/puts in netlbl_cipsov4_list().
2. Decrement the refcount on each attempt to remove the DOI from the
   DOI list, only removing it from the list once the refcount drops
   to zero.

This patch fixes these problems by adding the missing "puts" to
netlbl_cipsov4_list() and introduces a more conventional, i.e.
not-buggy, refcounting mechanism to the DOI definitions.  Upon the
addition of a DOI to the DOI list, it is initialized with a refcount
of one, removing a DOI from the list removes it from the list and
drops the refcount by one; "gets" and "puts" behave as expected with
respect to refcounts, increasing and decreasing the DOI's refcount by
one.

Fixes: b1edeb102397 ("netlabel: Replace protocol/NetLabel linking with refrerence counts")
Fixes: d7cce01504a0 ("netlabel: Add support for removing a CALIPSO DOI.")
Reported-by: syzbot+9ec037722d2603a9f52e@syzkaller.appspotmail.com
Signed-off-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>
2021-03-17 17:06:15 +01:00
Ido Schimmel
9c61f1e1c4 nexthop: Do not flush blackhole nexthops when loopback goes down
commit 76c03bf8e2624076b88d93542d78e22d5345c88e upstream.

As far as user space is concerned, blackhole nexthops do not have a
nexthop device and therefore should not be affected by the
administrative or carrier state of any netdev.

However, when the loopback netdev goes down all the blackhole nexthops
are flushed. This happens because internally the kernel associates
blackhole nexthops with the loopback netdev.

This behavior is both confusing to those not familiar with kernel
internals and also diverges from the legacy API where blackhole IPv4
routes are not flushed when the loopback netdev goes down:

 # ip route add blackhole 198.51.100.0/24
 # ip link set dev lo down
 # ip route show 198.51.100.0/24
 blackhole 198.51.100.0/24

Blackhole IPv6 routes are flushed, but at least user space knows that
they are associated with the loopback netdev:

 # ip -6 route show 2001:db8:1::/64
 blackhole 2001:db8:1::/64 dev lo metric 1024 pref medium

Fix this by only flushing blackhole nexthops when the loopback netdev is
unregistered.

Fixes: ab84be7e54fc ("net: Initial nexthop code")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reported-by: Donald Sharp <sharpd@nvidia.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>
2021-03-17 17:06:14 +01:00
Jason A. Donenfeld
91796b6556 net: always use icmp{,v6}_ndo_send from ndo_start_xmit
commit 4372339efc06bc2a796f4cc9d0a7a929dfda4967 upstream.

There were a few remaining tunnel drivers that didn't receive the prior
conversion to icmp{,v6}_ndo_send. Knowing now that this could lead to
memory corrution (see ee576c47db60 ("net: icmp: pass zeroed opts from
icmp{,v6}_ndo_send before sending") for details), there's even more
imperative to have these all converted. So this commit goes through the
remaining cases that I could find and does a boring translation to the
ndo variety.

The Fixes: line below is the merge that originally added icmp{,v6}_
ndo_send and converted the first batch of icmp{,v6}_send users. The
rationale then for the change applies equally to this patch. It's just
that these drivers were left out of the initial conversion because these
network devices are hiding in net/ rather than in drivers/net/.

Cc: Florian Westphal <fw@strlen.de>
Cc: Willem de Bruijn <willemb@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Fixes: 803381f9f117 ("Merge branch 'icmp-account-for-NAT-when-sending-icmps-from-ndo-layer'")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:12 +01:00
Eric Dumazet
046f3c1c2f tcp: add sanity tests to TCP_QUEUE_SEQ
commit 8811f4a9836e31c14ecdf79d9f3cb7c5d463265d upstream.

Qingyu Li reported a syzkaller bug where the repro
changes RCV SEQ _after_ restoring data in the receive queue.

mprotect(0x4aa000, 12288, PROT_READ)    = 0
mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000
socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0
connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0
setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0
sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20
setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0
setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0
recvfrom(3, NULL, 20, 0, NULL, NULL)    = -1 ECONNRESET (Connection reset by peer)

syslog shows:
[  111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0
[  111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0

This should not be allowed. TCP_QUEUE_SEQ should only be used
when queues are empty.

This patch fixes this case, and the tx path as well.

Fixes: ee9952831cfd ("tcp: Initial repair mode")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=212005
Reported-by: Qingyu Li <ieatmuttonchuan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:11 +01:00
Arjun Roy
e95ebe1ed6 tcp: Fix sign comparison bug in getsockopt(TCP_ZEROCOPY_RECEIVE)
commit 2107d45f17bedd7dbf4178462da0ac223835a2a7 upstream.

getsockopt(TCP_ZEROCOPY_RECEIVE) has a bug where we read a
user-provided "len" field of type signed int, and then compare the
value to the result of an "offsetofend" operation, which is unsigned.

Negative values provided by the user will be promoted to large
positive numbers; thus checking that len < offsetofend() will return
false when the intention was that it return true.

Note that while len is originally checked for negative values earlier
on in do_tcp_getsockopt(), subsequent calls to get_user() re-read the
value from userspace which may have changed in the meantime.

Therefore, re-add the check for negative values after the call to
get_user in the handler code for TCP_ZEROCOPY_RECEIVE.

Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Arjun Roy <arjunroy@google.com>
Link: https://lore.kernel.org/r/20210225232628.4033281-1-arjunroy.kdev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:11 +01:00
Daniel Borkmann
09af4362ba net: Fix gro aggregation for udp encaps with zero csum
commit 89e5c58fc1e2857ccdaae506fb8bc5fed57ee063 upstream.

We noticed a GRO issue for UDP-based encaps such as vxlan/geneve when the
csum for the UDP header itself is 0. In that case, GRO aggregation does
not take place on the phys dev, but instead is deferred to the vxlan/geneve
driver (see trace below).

The reason is essentially that GRO aggregation bails out in udp_gro_receive()
for such case when drivers marked the skb with CHECKSUM_UNNECESSARY (ice, i40e,
others) where for non-zero csums 2abb7cdc0dc8 ("udp: Add support for doing
checksum unnecessary conversion") promotes those skbs to CHECKSUM_COMPLETE
and napi context has csum_valid set. This is however not the case for zero
UDP csum (here: csum_cnt is still 0 and csum_valid continues to be false).

At the same time 57c67ff4bd92 ("udp: additional GRO support") added matches
on !uh->check ^ !uh2->check as part to determine candidates for aggregation,
so it certainly is expected to handle zero csums in udp_gro_receive(). The
purpose of the check added via 662880f44203 ("net: Allow GRO to use and set
levels of checksum unnecessary") seems to catch bad csum and stop aggregation
right away.

One way to fix aggregation in the zero case is to only perform the !csum_valid
check in udp_gro_receive() if uh->check is infact non-zero.

Before:

  [...]
  swapper     0 [008]   731.946506: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100400 len=1500   (1)
  swapper     0 [008]   731.946507: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100200 len=1500
  swapper     0 [008]   731.946507: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101100 len=1500
  swapper     0 [008]   731.946508: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101700 len=1500
  swapper     0 [008]   731.946508: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101b00 len=1500
  swapper     0 [008]   731.946508: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100600 len=1500
  swapper     0 [008]   731.946508: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100f00 len=1500
  swapper     0 [008]   731.946509: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100a00 len=1500
  swapper     0 [008]   731.946516: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100500 len=1500
  swapper     0 [008]   731.946516: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100700 len=1500
  swapper     0 [008]   731.946516: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101d00 len=1500   (2)
  swapper     0 [008]   731.946517: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101000 len=1500
  swapper     0 [008]   731.946517: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101c00 len=1500
  swapper     0 [008]   731.946517: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101400 len=1500
  swapper     0 [008]   731.946518: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100e00 len=1500
  swapper     0 [008]   731.946518: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497101600 len=1500
  swapper     0 [008]   731.946521: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff966497100800 len=774
  swapper     0 [008]   731.946530: net:netif_receive_skb: dev=test_vxlan skbaddr=0xffff966497100400 len=14032 (1)
  swapper     0 [008]   731.946530: net:netif_receive_skb: dev=test_vxlan skbaddr=0xffff966497101d00 len=9112  (2)
  [...]

  # netperf -H 10.55.10.4 -t TCP_STREAM -l 20
  MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.55.10.4 () port 0 AF_INET : demo
  Recv   Send    Send
  Socket Socket  Message  Elapsed
  Size   Size    Size     Time     Throughput
  bytes  bytes   bytes    secs.    10^6bits/sec

   87380  16384  16384    20.01    13129.24

After:

  [...]
  swapper     0 [026]   521.862641: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff93ab0d479000 len=11286 (1)
  swapper     0 [026]   521.862643: net:netif_receive_skb: dev=test_vxlan skbaddr=0xffff93ab0d479000 len=11236 (1)
  swapper     0 [026]   521.862650: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff93ab0d478500 len=2898  (2)
  swapper     0 [026]   521.862650: net:netif_receive_skb: dev=enp10s0f0  skbaddr=0xffff93ab0d479f00 len=8490  (3)
  swapper     0 [026]   521.862653: net:netif_receive_skb: dev=test_vxlan skbaddr=0xffff93ab0d478500 len=2848  (2)
  swapper     0 [026]   521.862653: net:netif_receive_skb: dev=test_vxlan skbaddr=0xffff93ab0d479f00 len=8440  (3)
  [...]

  # netperf -H 10.55.10.4 -t TCP_STREAM -l 20
  MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.55.10.4 () port 0 AF_INET : demo
  Recv   Send    Send
  Socket Socket  Message  Elapsed
  Size   Size    Size     Time     Throughput
  bytes  bytes   bytes    secs.    10^6bits/sec

   87380  16384  16384    20.01    24576.53

Fixes: 57c67ff4bd92 ("udp: additional GRO support")
Fixes: 662880f44203 ("net: Allow GRO to use and set levels of checksum unnecessary")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tom Herbert <tom@herbertland.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20210226212248.8300-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:11 +01:00
Jason A. Donenfeld
ce4feb0111 net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending
commit ee576c47db60432c37e54b1e2b43a8ca6d3a8dca upstream.

The icmp{,v6}_send functions make all sorts of use of skb->cb, casting
it with IPCB or IP6CB, assuming the skb to have come directly from the
inet layer. But when the packet comes from the ndo layer, especially
when forwarded, there's no telling what might be in skb->cb at that
point. As a result, the icmp sending code risks reading bogus memory
contents, which can result in nasty stack overflows such as this one
reported by a user:

    panic+0x108/0x2ea
    __stack_chk_fail+0x14/0x20
    __icmp_send+0x5bd/0x5c0
    icmp_ndo_send+0x148/0x160

In icmp_send, skb->cb is cast with IPCB and an ip_options struct is read
from it. The optlen parameter there is of particular note, as it can
induce writes beyond bounds. There are quite a few ways that can happen
in __ip_options_echo. For example:

    // sptr/skb are attacker-controlled skb bytes
    sptr = skb_network_header(skb);
    // dptr/dopt points to stack memory allocated by __icmp_send
    dptr = dopt->__data;
    // sopt is the corrupt skb->cb in question
    if (sopt->rr) {
        optlen  = sptr[sopt->rr+1]; // corrupt skb->cb + skb->data
        soffset = sptr[sopt->rr+2]; // corrupt skb->cb + skb->data
	// this now writes potentially attacker-controlled data, over
	// flowing the stack:
        memcpy(dptr, sptr+sopt->rr, optlen);
    }

In the icmpv6_send case, the story is similar, but not as dire, as only
IP6CB(skb)->iif and IP6CB(skb)->dsthao are used. The dsthao case is
worse than the iif case, but it is passed to ipv6_find_tlv, which does
a bit of bounds checking on the value.

This is easy to simulate by doing a `memset(skb->cb, 0x41,
sizeof(skb->cb));` before calling icmp{,v6}_ndo_send, and it's only by
good fortune and the rarity of icmp sending from that context that we've
avoided reports like this until now. For example, in KASAN:

    BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0xa0e/0x12b0
    Write of size 38 at addr ffff888006f1f80e by task ping/89
    CPU: 2 PID: 89 Comm: ping Not tainted 5.10.0-rc7-debug+ #5
    Call Trace:
     dump_stack+0x9a/0xcc
     print_address_description.constprop.0+0x1a/0x160
     __kasan_report.cold+0x20/0x38
     kasan_report+0x32/0x40
     check_memory_region+0x145/0x1a0
     memcpy+0x39/0x60
     __ip_options_echo+0xa0e/0x12b0
     __icmp_send+0x744/0x1700

Actually, out of the 4 drivers that do this, only gtp zeroed the cb for
the v4 case, while the rest did not. So this commit actually removes the
gtp-specific zeroing, while putting the code where it belongs in the
shared infrastructure of icmp{,v6}_ndo_send.

This commit fixes the issue by passing an empty IPCB or IP6CB along to
the functions that actually do the work. For the icmp_send, this was
already trivial, thanks to __icmp_send providing the plumbing function.
For icmpv6_send, this required a tiny bit of refactoring to make it
behave like the v4 case, after which it was straight forward.

Fixes: a2b78e9b2cac ("sunvnet: generate ICMP PTMUD messages for smaller port MTUs")
Reported-by: SinYu <liuxyon@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/netdev/CAF=yD-LOF116aHub6RMe8vB8ZpnrrnoTdqhobEx+bvoA8AsP0w@mail.gmail.com/T/
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20210223131858.72082-1-Jason@zx2c4.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:46 +01:00
Dongseok Yi
3d6df63a5c udp: ipv4: manipulate network header of NATed UDP GRO fraglist
commit c3df39ac9b0e3747bf8233ea9ce4ed5ceb3199d3 upstream.

UDP/IP header of UDP GROed frag_skbs are not updated even after NAT
forwarding. Only the header of head_skb from ip_finish_output_gso ->
skb_gso_segment is updated but following frag_skbs are not updated.

A call path skb_mac_gso_segment -> inet_gso_segment ->
udp4_ufo_fragment -> __udp_gso_segment -> __udp_gso_segment_list
does not try to update UDP/IP header of the segment list but copy
only the MAC header.

Update port, addr and check of each skb of the segment list in
__udp_gso_segment_list. It covers both SNAT and DNAT.

Fixes: 9fd1ff5d2ac7 (udp: Support UDP fraglist GRO/GSO.)
Signed-off-by: Dongseok Yi <dseok.yi@samsung.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Link: https://lore.kernel.org/r/1611962007-80092-1-git-send-email-dseok.yi@samsung.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10 09:29:23 +01:00
Vadim Fedorenko
f2b30f9f08 net: ip_tunnel: fix mtu calculation
commit 28e104d00281ade30250b24e098bf50887671ea4 upstream.

dev->hard_header_len for tunnel interface is set only when header_ops
are set too and already contains full overhead of any tunnel encapsulation.
That's why there is not need to use this overhead twice in mtu calc.

Fixes: fdafed459998 ("ip_gre: set dev->hard_header_len and dev->needed_headroom properly")
Reported-by: Slava Bacherikov <mail@slava.cc>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Link: https://lore.kernel.org/r/1611959267-20536-1-git-send-email-vfedorenko@novek.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10 09:29:22 +01:00
Pengcheng Yang
a9cd144eb7 tcp: fix TLP timer not set when CA_STATE changes from DISORDER to OPEN
commit 62d9f1a6945ba69c125e548e72a36d203b30596e upstream.

Upon receiving a cumulative ACK that changes the congestion state from
Disorder to Open, the TLP timer is not set. If the sender is app-limited,
it can only wait for the RTO timer to expire and retransmit.

The reason for this is that the TLP timer is set before the congestion
state changes in tcp_ack(), so we delay the time point of calling
tcp_set_xmit_timer() until after tcp_fastretrans_alert() returns and
remove the FLAG_SET_XMIT_TIMER from ack_flag when the RACK reorder timer
is set.

This commit has two additional benefits:
1) Make sure to reset RTO according to RFC6298 when receiving ACK, to
avoid spurious RTO caused by RTO timer early expires.
2) Reduce the xmit timer reschedule once per ACK when the RACK reorder
timer is set.

Fixes: df92c8394e6e ("tcp: fix xmit timer to only be reset if data ACKed/SACKed")
Link: https://lore.kernel.org/netdev/1611311242-6675-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/1611464834-23030-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-03 23:28:52 +01:00
Enke Chen
011c3d9427 tcp: make TCP_USER_TIMEOUT accurate for zero window probes
commit 344db93ae3ee69fc137bd6ed89a8ff1bf5b0db08 upstream.

The TCP_USER_TIMEOUT is checked by the 0-window probe timer. As the
timer has backoff with a max interval of about two minutes, the
actual timeout for TCP_USER_TIMEOUT can be off by up to two minutes.

In this patch the TCP_USER_TIMEOUT is made more accurate by taking it
into account when computing the timer value for the 0-window probes.

This patch is similar to and builds on top of the one that made
TCP_USER_TIMEOUT accurate for RTOs in commit b701a99e431d ("tcp: Add
tcp_clamp_rto_to_user_timeout() helper to improve accuracy").

Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT")
Signed-off-by: Enke Chen <enchen@paloaltonetworks.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210122191306.GA99540@localhost.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-03 23:28:51 +01:00
Kuniyuki Iwashima
e9c4068fb0 tcp: Fix potential use-after-free due to double kfree()
commit c89dffc70b340780e5b933832d8c3e045ef3791e upstream.

Receiving ACK with a valid SYN cookie, cookie_v4_check() allocates struct
request_sock and then can allocate inet_rsk(req)->ireq_opt. After that,
tcp_v4_syn_recv_sock() allocates struct sock and copies ireq_opt to
inet_sk(sk)->inet_opt. Normally, tcp_v4_syn_recv_sock() inserts the full
socket into ehash and sets NULL to ireq_opt. Otherwise,
tcp_v4_syn_recv_sock() has to reset inet_opt by NULL and free the full
socket.

The commit 01770a1661657 ("tcp: fix race condition when creating child
sockets from syncookies") added a new path, in which more than one cores
create full sockets for the same SYN cookie. Currently, the core which
loses the race frees the full socket without resetting inet_opt, resulting
in that both sock_put() and reqsk_put() call kfree() for the same memory:

  sock_put
    sk_free
      __sk_free
        sk_destruct
          __sk_destruct
            sk->sk_destruct/inet_sock_destruct
              kfree(rcu_dereference_protected(inet->inet_opt, 1));

  reqsk_put
    reqsk_free
      __reqsk_free
        req->rsk_ops->destructor/tcp_v4_reqsk_destructor
          kfree(rcu_dereference_protected(inet_rsk(req)->ireq_opt, 1));

Calling kmalloc() between the double kfree() can lead to use-after-free, so
this patch fixes it by setting NULL to inet_opt before sock_put().

As a side note, this kind of issue does not happen for IPv6. This is
because tcp_v6_syn_recv_sock() clones both ipv6_opt and pktopts which
correspond to ireq_opt in IPv4.

Fixes: 01770a166165 ("tcp: fix race condition when creating child sockets from syncookies")
CC: Ricardo Dias <rdias@singlestore.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210118055920.82516-1-kuniyu@amazon.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:55:28 +01:00