Commit Graph

116 Commits

Author SHA1 Message Date
Yan Zhai
46a02aa357 tcp: use sk_skb_reason_drop to free rx packets
Replace kfree_skb_reason with sk_skb_reason_drop and pass the receiving
socket to the tracepoint.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202406011539.jhwBd7DX-lkp@intel.com/
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-06-19 12:44:22 +01:00
Eric Dumazet
f410cbea9f tcp: annotate data-races around tp->window_clamp
tp->window_clamp can be read locklessly, add READ_ONCE()
and WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20240404114231.2195171-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-05 22:32:37 -07:00
Kuniyuki Iwashima
956c0d6191 tcp: Clear req->syncookie in reqsk_alloc().
syzkaller reported a read of uninit req->syncookie. [0]

Originally, req->syncookie was used only in tcp_conn_request()
to indicate if we need to encode SYN cookie in SYN+ACK, so the
field remains uninitialised in other places.

The commit 695751e31a ("bpf: tcp: Handle BPF SYN Cookie in
cookie_v[46]_check().") added another meaning in ACK path;
req->syncookie is set true if SYN cookie is validated by BPF
kfunc.

After the change, cookie_v[46]_check() always read req->syncookie,
but it is not initialised in the normal SYN cookie case as reported
by KMSAN.

Let's make sure we always initialise req->syncookie in reqsk_alloc().

[0]:
BUG: KMSAN: uninit-value in cookie_v4_check+0x22b7/0x29e0
 net/ipv4/syncookies.c:477
 cookie_v4_check+0x22b7/0x29e0 net/ipv4/syncookies.c:477
 tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1855 [inline]
 tcp_v4_do_rcv+0xb17/0x10b0 net/ipv4/tcp_ipv4.c:1914
 tcp_v4_rcv+0x4ce4/0x5420 net/ipv4/tcp_ipv4.c:2322
 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x332/0x500 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:460 [inline]
 ip_rcv_finish+0x4a2/0x520 net/ipv4/ip_input.c:449
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core net/core/dev.c:5538 [inline]
 __netif_receive_skb+0x319/0x9e0 net/core/dev.c:5652
 process_backlog+0x480/0x8b0 net/core/dev.c:5981
 __napi_poll+0xe7/0x980 net/core/dev.c:6632
 napi_poll net/core/dev.c:6701 [inline]
 net_rx_action+0x89d/0x1820 net/core/dev.c:6813
 __do_softirq+0x1c0/0x7d7 kernel/softirq.c:554
 do_softirq+0x9a/0x100 kernel/softirq.c:455
 __local_bh_enable_ip+0x9f/0xb0 kernel/softirq.c:382
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:820 [inline]
 __dev_queue_xmit+0x2776/0x52c0 net/core/dev.c:4362
 dev_queue_xmit include/linux/netdevice.h:3091 [inline]
 neigh_hh_output include/net/neighbour.h:526 [inline]
 neigh_output include/net/neighbour.h:540 [inline]
 ip_finish_output2+0x187a/0x1b70 net/ipv4/ip_output.c:235
 __ip_finish_output+0x287/0x810
 ip_finish_output+0x4b/0x550 net/ipv4/ip_output.c:323
 NF_HOOK_COND include/linux/netfilter.h:303 [inline]
 ip_output+0x15f/0x3f0 net/ipv4/ip_output.c:433
 dst_output include/net/dst.h:450 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x1e93/0x2030 net/ipv4/ip_output.c:535
 ip_queue_xmit+0x60/0x80 net/ipv4/ip_output.c:549
 __tcp_transmit_skb+0x3c70/0x4890 net/ipv4/tcp_output.c:1462
 tcp_transmit_skb net/ipv4/tcp_output.c:1480 [inline]
 tcp_write_xmit+0x3ee1/0x8900 net/ipv4/tcp_output.c:2792
 __tcp_push_pending_frames net/ipv4/tcp_output.c:2977 [inline]
 tcp_send_fin+0xa90/0x12e0 net/ipv4/tcp_output.c:3578
 tcp_shutdown+0x198/0x1f0 net/ipv4/tcp.c:2716
 inet_shutdown+0x33f/0x5b0 net/ipv4/af_inet.c:923
 __sys_shutdown_sock net/socket.c:2425 [inline]
 __sys_shutdown net/socket.c:2437 [inline]
 __do_sys_shutdown net/socket.c:2445 [inline]
 __se_sys_shutdown+0x2a4/0x440 net/socket.c:2443
 __x64_sys_shutdown+0x6c/0xa0 net/socket.c:2443
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was stored to memory at:
 reqsk_alloc include/net/request_sock.h:148 [inline]
 inet_reqsk_alloc+0x651/0x7a0 net/ipv4/tcp_input.c:6978
 cookie_tcp_reqsk_alloc+0xd4/0x900 net/ipv4/syncookies.c:328
 cookie_tcp_check net/ipv4/syncookies.c:388 [inline]
 cookie_v4_check+0x289f/0x29e0 net/ipv4/syncookies.c:420
 tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1855 [inline]
 tcp_v4_do_rcv+0xb17/0x10b0 net/ipv4/tcp_ipv4.c:1914
 tcp_v4_rcv+0x4ce4/0x5420 net/ipv4/tcp_ipv4.c:2322
 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x332/0x500 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:460 [inline]
 ip_rcv_finish+0x4a2/0x520 net/ipv4/ip_input.c:449
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core net/core/dev.c:5538 [inline]
 __netif_receive_skb+0x319/0x9e0 net/core/dev.c:5652
 process_backlog+0x480/0x8b0 net/core/dev.c:5981
 __napi_poll+0xe7/0x980 net/core/dev.c:6632
 napi_poll net/core/dev.c:6701 [inline]
 net_rx_action+0x89d/0x1820 net/core/dev.c:6813
 __do_softirq+0x1c0/0x7d7 kernel/softirq.c:554

Uninit was created at:
 __alloc_pages+0x9a7/0xe00 mm/page_alloc.c:4592
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x2de/0x1400 mm/slub.c:2391
 ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x6d3/0xbe0 mm/slub.c:3852
 reqsk_alloc include/net/request_sock.h:131 [inline]
 inet_reqsk_alloc+0x66/0x7a0 net/ipv4/tcp_input.c:6978
 tcp_conn_request+0x484/0x44e0 net/ipv4/tcp_input.c:7135
 tcp_v4_conn_request+0x16f/0x1d0 net/ipv4/tcp_ipv4.c:1716
 tcp_rcv_state_process+0x2e5/0x4bb0 net/ipv4/tcp_input.c:6655
 tcp_v4_do_rcv+0xbfd/0x10b0 net/ipv4/tcp_ipv4.c:1929
 tcp_v4_rcv+0x4ce4/0x5420 net/ipv4/tcp_ipv4.c:2322
 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x332/0x500 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:460 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0x15f3/0x17f0 net/ipv4/ip_input.c:639
 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5581 [inline]
 __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5629
 __netif_receive_skb_list net/core/dev.c:5681 [inline]
 netif_receive_skb_list_internal+0x106c/0x16f0 net/core/dev.c:5773
 gro_normal_list include/net/gro.h:438 [inline]
 napi_complete_done+0x425/0x880 net/core/dev.c:6113
 virtqueue_napi_complete drivers/net/virtio_net.c:465 [inline]
 virtnet_poll+0x149d/0x2240 drivers/net/virtio_net.c:2211
 __napi_poll+0xe7/0x980 net/core/dev.c:6632
 napi_poll net/core/dev.c:6701 [inline]
 net_rx_action+0x89d/0x1820 net/core/dev.c:6813
 __do_softirq+0x1c0/0x7d7 kernel/softirq.c:554

CPU: 0 PID: 16792 Comm: syz-executor.2 Not tainted 6.8.0-syzkaller-05562-g61387b8dcf1d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024

Fixes: 695751e31a ("bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check().")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Closes: https://lore.kernel.org/bpf/CANn89iKdN9c+C_2JAUbc+VY3DDQjAQukMtiBbormAmAk9CdvQA@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240315224710.55209-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-19 19:35:59 -07:00
Jason Xing
253541a3c1 tcp: use drop reasons in cookie check for ipv6
Like what I did to ipv4 mode, refine this part: adding more drop
reasons for better tracing.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-28 10:39:21 +00:00
Jason Xing
ed43e76cdc tcp: directly drop skb in cookie check for ipv6
Like previous patch does, only moving skb drop logical code to
cookie_v6_check() for later refinement.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-28 10:39:21 +00:00
Kuniyuki Iwashima
695751e31a bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check().
We will support arbitrary SYN Cookie with BPF in the following
patch.

If BPF prog validates ACK and kfunc allocates a reqsk, it will
be carried to cookie_[46]_check() as skb->sk.  If skb->sk is not
NULL, we call cookie_bpf_check().

Then, we clear skb->sk and skb->destructor, which are needed not
to hold refcnt for reqsk and the listener.  See the following patch
for details.

After that, we finish initialisation for the remaining fields with
cookie_tcp_reqsk_init().

Note that the server side WScale is set only for non-BPF SYN Cookie.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240115205514.68364-5-kuniyu@amazon.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-23 14:40:24 -08:00
Kuniyuki Iwashima
8e7bab6b96 tcp: Factorise cookie-dependent fields initialisation in cookie_v[46]_check()
We will support arbitrary SYN Cookie with BPF, and then kfunc at
TC will preallocate reqsk and initialise some fields that should
not be overwritten later by cookie_v[46]_check().

To simplify the flow in cookie_v[46]_check(), we move such fields'
initialisation to cookie_tcp_reqsk_alloc() and factorise non-BPF
SYN Cookie handling into cookie_tcp_check(), where we validate the
cookie and allocate reqsk, as done by kfunc later.

Note that we set ireq->ecn_ok in two steps, the latter of which will
be shared by the BPF case.  As cookie_ecn_ok() is one-liner, now
it's inlined.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-9-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:16:38 -08:00
Kuniyuki Iwashima
de5626b95e tcp: Factorise cookie-independent fields initialisation in cookie_v[46]_check().
We will support arbitrary SYN Cookie with BPF, and then some reqsk fields
are initialised in kfunc, and others are done in cookie_v[46]_check().

This patch factorises the common part as cookie_tcp_reqsk_init() and
calls it in cookie_tcp_reqsk_alloc() to minimise the discrepancy between
cookie_v[46]_check().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:16:34 -08:00
Kuniyuki Iwashima
7b0f570f87 tcp: Move TCP-AO bits from cookie_v[46]_check() to tcp_ao_syncookie().
We initialise treq->af_specific in cookie_tcp_reqsk_alloc() so that
we can look up a key later in tcp_create_openreq_child().

Initially, that change was added for MD5 by commit ba5a4fdd63 ("tcp:
make sure treq->af_specific is initialized"), but it has not been used
since commit d0f2b7a9ca ("tcp: Disable header prediction for MD5
flow.").

Now, treq->af_specific is used only by TCP-AO, so, we can move that
initialisation into tcp_ao_syncookie().

In addition to that, l3index in cookie_v[46]_check() is only used for
tcp_ao_syncookie(), so let's move it as well.

While at it, we move down tcp_ao_syncookie() in cookie_v4_check() so
that it will be called after security_inet_conn_request() to make
functions order consistent with cookie_v6_check().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:16:28 -08:00
Kuniyuki Iwashima
efce3d1fdf tcp: Don't initialise tp->tsoffset in tcp_get_cookie_sock().
When we create a full socket from SYN Cookie, we initialise
tcp_sk(sk)->tsoffset redundantly in tcp_get_cookie_sock() as
the field is inherited from tcp_rsk(req)->ts_off.

  cookie_v[46]_check
  |- treq->ts_off = 0
  `- tcp_get_cookie_sock
     |- tcp_v[46]_syn_recv_sock
     |  `- tcp_create_openreq_child
     |	   `- newtp->tsoffset = treq->ts_off
     `- tcp_sk(child)->tsoffset = tsoff

Let's initialise tcp_rsk(req)->ts_off with the correct offset
and remove the second initialisation of tcp_sk(sk)->tsoffset.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:16:23 -08:00
Kuniyuki Iwashima
7577bc8249 tcp: Don't pass cookie to __cookie_v[46]_check().
tcp_hdr(skb) and SYN Cookie are passed to __cookie_v[46]_check(), but
none of the callers passes cookie other than ntohl(th->ack_seq) - 1.

Let's fetch it in __cookie_v[46]_check() instead of passing the cookie
over and over.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-5-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:16:19 -08:00
Kuniyuki Iwashima
50468cddd6 tcp: Clean up goto labels in cookie_v[46]_check().
We will support arbitrary SYN Cookie with BPF, and then reqsk
will be preallocated before cookie_v[46]_check().

Depending on how validation fails, we send RST or just drop skb.

To make the error handling easier, let's clean up goto labels.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:16:14 -08:00
Kuniyuki Iwashima
45c28509fe tcp: Cache sock_net(sk) in cookie_v[46]_check().
sock_net(sk) is used repeatedly in cookie_v[46]_check().
Let's cache it in a variable.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:16:09 -08:00
Kuniyuki Iwashima
34efc9cfe7 tcp: Clean up reverse xmas tree in cookie_v[46]_check().
We will grow and cut the xmas tree in cookie_v[46]_check().
This patch cleans it up to make later patches tidy.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29 20:15:32 -08:00
Kuniyuki Iwashima
23be1e0e2a dccp/tcp: Call security_inet_conn_request() after setting IPv6 addresses.
Initially, commit 4237c75c0a ("[MLSXFRM]: Auto-labeling of child
sockets") introduced security_inet_conn_request() in some functions
where reqsk is allocated.  The hook is added just after the allocation,
so reqsk's IPv6 remote address was not initialised then.

However, SELinux/Smack started to read it in netlbl_req_setattr()
after commit e1adea9270 ("calipso: Allow request sockets to be
relabelled by the lsm.").

Commit 284904aa79 ("lsm: Relocate the IPv4 security_inet_conn_request()
hooks") fixed that kind of issue only in TCPv4 because IPv6 labeling was
not supported at that time.  Finally, the same issue was introduced again
in IPv6.

Let's apply the same fix on DCCPv6 and TCPv6.

Fixes: e1adea9270 ("calipso: Allow request sockets to be relabelled by the lsm.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-11-02 12:56:03 +01:00
Dmitry Safonov
248411b8cb net/tcp: Wire up l3index to TCP-AO
Similarly how TCP_MD5SIG_FLAG_IFINDEX works for TCP-MD5,
TCP_AO_KEYF_IFINDEX is an AO-key flag that binds that MKT to a specified
by L3 ifinndex. Similarly, without this flag the key will work in
the default VRF l3index = 0 for connections.
To prevent AO-keys from overlapping, it's restricted to add key B for a
socket that has key A, which have the same sndid/rcvid and one of
the following is true:
- !(A.keyflags & TCP_AO_KEYF_IFINDEX) or !(B.keyflags & TCP_AO_KEYF_IFINDEX)
  so that any key is non-bound to a VRF
- A.l3index == B.l3index
  both want to work for the same VRF

Additionally, it's restricted to match TCP-MD5 keys for the same peer
the following way:
|--------------|--------------------|----------------|---------------|
|              | MD5 key without    |     MD5 key    |    MD5 key    |
|              |     l3index        |    l3index=0   |   l3index=N   |
|--------------|--------------------|----------------|---------------|
|  TCP-AO key  |                    |                |               |
|  without     |       reject       |    reject      |   reject      |
|  l3index     |                    |                |               |
|--------------|--------------------|----------------|---------------|
|  TCP-AO key  |                    |                |               |
|  l3index=0   |       reject       |    reject      |   allow       |
|--------------|--------------------|----------------|---------------|
|  TCP-AO key  |                    |                |               |
|  l3index=N   |       reject       |    allow       |   reject      |
|--------------|--------------------|----------------|---------------|

This is done with the help of tcp_md5_do_lookup_any_l3index() to reject
adding AO key without TCP_AO_KEYF_IFINDEX if there's TCP-MD5 in any VRF.
This is important for case where sysctl_tcp_l3mdev_accept = 1
Similarly, for TCP-AO lookups tcp_ao_do_lookup() may be used with
l3index < 0, so that __tcp_ao_key_cmp() will match TCP-AO key in any VRF.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27 10:35:46 +01:00
Dmitry Safonov
06b22ef295 net/tcp: Wire TCP-AO to request sockets
Now when the new request socket is created from the listening socket,
it's recorded what MKT was used by the peer. tcp_rsk_used_ao() is
a new helper for checking if TCP-AO option was used to create the
request socket.
tcp_ao_copy_all_matching() will copy all keys that match the peer on the
request socket, as well as preparing them for the usage (creating
traffic keys).

Co-developed-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Co-developed-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27 10:35:45 +01:00
Kuniyuki Iwashima
f2e383b5bb tcp: Fix data-races around sysctl_tcp_syncookies.
While reading sysctl_tcp_syncookies, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 12:21:54 +01:00
Eric Dumazet
ba5a4fdd63 tcp: make sure treq->af_specific is initialized
syzbot complained about a recent change in TCP stack,
hitting a NULL pointer [1]

tcp request sockets have an af_specific pointer, which
was used before the blamed change only for SYNACK generation
in non SYNCOOKIE mode.

tcp requests sockets momentarily created when third packet
coming from client in SYNCOOKIE mode were not using
treq->af_specific.

Make sure this field is populated, in the same way normal
TCP requests sockets do in tcp_conn_request().

[1]
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 3695 Comm: syz-executor864 Not tainted 5.18.0-rc3-syzkaller-00224-g5fd1fe4807f9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_create_openreq_child+0xe16/0x16b0 net/ipv4/tcp_minisocks.c:534
Code: 48 c1 ea 03 80 3c 02 00 0f 85 e5 07 00 00 4c 8b b3 28 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7e 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c9 07 00 00 48 8b 3c 24 48 89 de 41 ff 56 08 48
RSP: 0018:ffffc90000de0588 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888076490330 RCX: 0000000000000100
RDX: 0000000000000001 RSI: ffffffff87d67ff0 RDI: 0000000000000008
RBP: ffff88806ee1c7f8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87d67f00 R11: 0000000000000000 R12: ffff88806ee1bfc0
R13: ffff88801b0e0368 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f517fe58700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcead76960 CR3: 000000006f97b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 tcp_v6_syn_recv_sock+0x199/0x23b0 net/ipv6/tcp_ipv6.c:1267
 tcp_get_cookie_sock+0xc9/0x850 net/ipv4/syncookies.c:207
 cookie_v6_check+0x15c3/0x2340 net/ipv6/syncookies.c:258
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1131 [inline]
 tcp_v6_do_rcv+0x1148/0x13b0 net/ipv6/tcp_ipv6.c:1486
 tcp_v6_rcv+0x3305/0x3840 net/ipv6/tcp_ipv6.c:1725
 ip6_protocol_deliver_rcu+0x2e9/0x1900 net/ipv6/ip6_input.c:422
 ip6_input_finish+0x14c/0x2c0 net/ipv6/ip6_input.c:464
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:473
 dst_input include/net/dst.h:461 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ipv6_rcv+0x27f/0x3b0 net/ipv6/ip6_input.c:297
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519
 process_backlog+0x3a0/0x7c0 net/core/dev.c:5847
 __napi_poll+0xb3/0x6e0 net/core/dev.c:6413
 napi_poll net/core/dev.c:6480 [inline]
 net_rx_action+0x8ec/0xc60 net/core/dev.c:6567
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097

Fixes: 5b0b9e4c2c ("tcp: md5: incorrect tcp_header_len for incoming connections")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-25 12:10:11 +01:00
Eric Dumazet
49ecc2e9c3 net: align static siphash keys
siphash keys use 16 bytes.

Define siphash_aligned_key_t macro so that we can make sure they
are not crossing a cache line boundary.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-16 19:07:54 -08:00
Linus Torvalds
ca5b877b6c selinux/stable-5.11 PR 20201214
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Merge tag 'selinux-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "While we have a small number of SELinux patches for v5.11, there are a
  few changes worth highlighting:

   - Change the LSM network hooks to pass flowi_common structs instead
     of the parent flowi struct as the LSMs do not currently need the
     full flowi struct and they do not have enough information to use it
     safely (missing information on the address family).

     This patch was discussed both with Herbert Xu (representing team
     netdev) and James Morris (representing team
     LSMs-other-than-SELinux).

   - Fix how we handle errors in inode_doinit_with_dentry() so that we
     attempt to properly label the inode on following lookups instead of
     continuing to treat it as unlabeled.

   - Tweak the kernel logic around allowx, auditallowx, and dontauditx
     SELinux policy statements such that the auditx/dontauditx are
     effective even without the allowx statement.

  Everything passes our test suite"

* tag 'selinux-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  lsm,selinux: pass flowi_common instead of flowi to the LSM hooks
  selinux: Fix fall-through warnings for Clang
  selinux: drop super_block backpointer from superblock_security_struct
  selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling
  selinux: allow dontauditx and auditallowx rules to take effect without allowx
  selinux: fix error initialization in inode_doinit_with_dentry()
2020-12-16 11:01:04 -08:00
Paul Moore
3df98d7921 lsm,selinux: pass flowi_common instead of flowi to the LSM hooks
As pointed out by Herbert in a recent related patch, the LSM hooks do
not have the necessary address family information to use the flowi
struct safely.  As none of the LSMs currently use any of the protocol
specific flowi information, replace the flowi pointers with pointers
to the address family independent flowi_common struct.

Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-11-23 18:36:21 -05:00
Mao Wenan
909172a149 net: Update window_clamp if SOCK_RCVBUF is set
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: e88c64f0a4 ("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>
2020-11-10 17:42:35 -08:00
Florian Westphal
6fc8c827dd tcp: syncookies: create mptcp request socket for ACK cookies with MPTCP option
If SYN packet contains MP_CAPABLE option, keep it enabled.
Syncokie validation and cookie-based socket creation is changed to
instantiate an mptcp request sockets if the ACK contains an MPTCP
connection request.

Rather than extend both cookie_v4/6_check, add a common helper to create
the (mp)tcp request socket.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-31 16:55:32 -07:00
Florian Westphal
ae2dd71649 mptcp: handle tcp fallback when using syn cookies
We can't deal with syncookie mode yet, the syncookie rx path will create
tcp reqsk, i.e. we get OOB access because we treat tcp reqsk as mptcp reqsk one:

TCP: SYN flooding on port 20002. Sending cookies.
BUG: KASAN: slab-out-of-bounds in subflow_syn_recv_sock+0x451/0x4d0 net/mptcp/subflow.c:191
Read of size 1 at addr ffff8881167bc148 by task syz-executor099/2120
 subflow_syn_recv_sock+0x451/0x4d0 net/mptcp/subflow.c:191
 tcp_get_cookie_sock+0xcf/0x520 net/ipv4/syncookies.c:209
 cookie_v6_check+0x15a5/0x1e90 net/ipv6/syncookies.c:252
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1123 [inline]
 [..]

Bug can be reproduced via "sysctl net.ipv4.tcp_syncookies=2".

Note that MPTCP should work with syncookies (4th ack would carry needed
state), but it appears better to sort that out in -next so do tcp
fallback for now.

I removed the MPTCP ifdef for tcp_rsk "is_mptcp" member because
if (IS_ENABLED()) is easier to read than "#ifdef IS_ENABLED()/#endif" pair.

Cc: Eric Dumazet <edumazet@google.com>
Fixes: cec37a6e41 ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-29 17:45:20 +01:00
Sabrina Dubroca
c4e85f73af net: ipv6: add net argument to ip6_dst_lookup_flow
This will be used in the conversion of ipv6_stub to ip6_dst_lookup_flow,
as some modules currently pass a net argument without a socket to
ip6_dst_lookup. This is equivalent to commit 343d60aada ("ipv6: change
ipv6_stub_impl.ipv6_dst_lookup to take net argument").

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-04 12:27:12 -08:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Hans Wippel
bc58a1baf2 net/ipv4: disable SMC TCP option with SYN Cookies
Currently, the SMC experimental TCP option in a SYN packet is lost on
the server side when SYN Cookies are active. However, the corresponding
SYNACK sent back to the client contains the SMC option. This causes an
inconsistent view of the SMC capabilities on the client and server.

This patch disables the SMC option in the SYNACK when SYN Cookies are
active to avoid this issue.

Fixes: 60e2a77807 ("tcp: TCP experimental option for SMC")
Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-25 20:53:54 -04:00
Eric Dumazet
ceef9ab6be tcp: Namespace-ify sysctl_tcp_workaround_signed_windows
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28 19:24:38 +09:00
Alexander Potapenko
18bcf2907d ipv4: ipv6: initialize treq->txhash in cookie_v[46]_check()
KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(),
which originated from the TCP request socket created in
cookie_v6_check():

 ==================================================================
 BUG: KMSAN: use of uninitialized memory in tcp_transmit_skb+0xf77/0x3ec0
 CPU: 1 PID: 2949 Comm: syz-execprog Not tainted 4.11.0-rc5+ #2931
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 TCP: request_sock_TCPv6: Possible SYN flooding on port 20028. Sending cookies.  Check SNMP counters.
 Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:16
  dump_stack+0x172/0x1c0 lib/dump_stack.c:52
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:927
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:469
  skb_set_hash_from_sk ./include/net/sock.h:2011
  tcp_transmit_skb+0xf77/0x3ec0 net/ipv4/tcp_output.c:983
  tcp_send_ack+0x75b/0x830 net/ipv4/tcp_output.c:3493
  tcp_delack_timer_handler+0x9a6/0xb90 net/ipv4/tcp_timer.c:284
  tcp_delack_timer+0x1b0/0x310 net/ipv4/tcp_timer.c:309
  call_timer_fn+0x240/0x520 kernel/time/timer.c:1268
  expire_timers kernel/time/timer.c:1307
  __run_timers+0xc13/0xf10 kernel/time/timer.c:1601
  run_timer_softirq+0x36/0xa0 kernel/time/timer.c:1614
  __do_softirq+0x485/0x942 kernel/softirq.c:284
  invoke_softirq kernel/softirq.c:364
  irq_exit+0x1fa/0x230 kernel/softirq.c:405
  exiting_irq+0xe/0x10 ./arch/x86/include/asm/apic.h:657
  smp_apic_timer_interrupt+0x5a/0x80 arch/x86/kernel/apic/apic.c:966
  apic_timer_interrupt+0x86/0x90 arch/x86/entry/entry_64.S:489
 RIP: 0010:native_restore_fl ./arch/x86/include/asm/irqflags.h:36
 RIP: 0010:arch_local_irq_restore ./arch/x86/include/asm/irqflags.h:77
 RIP: 0010:__msan_poison_alloca+0xed/0x120 mm/kmsan/kmsan_instr.c:440
 RSP: 0018:ffff880024917cd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
 RAX: 0000000000000246 RBX: ffff8800224c0000 RCX: 0000000000000005
 RDX: 0000000000000004 RSI: ffff880000000000 RDI: ffffea0000b6d770
 RBP: ffff880024917d58 R08: 0000000000000dd8 R09: 0000000000000004
 R10: 0000160000000000 R11: 0000000000000000 R12: ffffffff85abf810
 R13: ffff880024917dd8 R14: 0000000000000010 R15: ffffffff81cabde4
  </IRQ>
  poll_select_copy_remaining+0xac/0x6b0 fs/select.c:293
  SYSC_select+0x4b4/0x4e0 fs/select.c:653
  SyS_select+0x76/0xa0 fs/select.c:634
  entry_SYSCALL_64_fastpath+0x13/0x94 arch/x86/entry/entry_64.S:204
 RIP: 0033:0x4597e7
 RSP: 002b:000000c420037ee0 EFLAGS: 00000246 ORIG_RAX: 0000000000000017
 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004597e7
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: 000000c420037ef0 R08: 000000c420037ee0 R09: 0000000000000059
 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000042dc20
 R13: 00000000000000f3 R14: 0000000000000030 R15: 0000000000000003
 chained origin:
  save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302
  kmsan_save_stack mm/kmsan/kmsan.c:317
  kmsan_internal_chain_origin+0x12a/0x1f0 mm/kmsan/kmsan.c:547
  __msan_store_shadow_origin_4+0xac/0x110 mm/kmsan/kmsan_instr.c:259
  tcp_create_openreq_child+0x709/0x1ae0 net/ipv4/tcp_minisocks.c:472
  tcp_v6_syn_recv_sock+0x7eb/0x2a30 net/ipv6/tcp_ipv6.c:1103
  tcp_get_cookie_sock+0x136/0x5f0 net/ipv4/syncookies.c:212
  cookie_v6_check+0x17a9/0x1b50 net/ipv6/syncookies.c:245
  tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989
  tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298
  tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487
  ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279
  NF_HOOK ./include/linux/netfilter.h:257
  ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322
  dst_input ./include/net/dst.h:492
  ip6_rcv_finish net/ipv6/ip6_input.c:69
  NF_HOOK ./include/linux/netfilter.h:257
  ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203
  __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208
  __netif_receive_skb net/core/dev.c:4246
  process_backlog+0x667/0xba0 net/core/dev.c:4866
  napi_poll net/core/dev.c:5268
  net_rx_action+0xc95/0x1590 net/core/dev.c:5333
  __do_softirq+0x485/0x942 kernel/softirq.c:284
 origin:
  save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302
  kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:198
  kmsan_kmalloc+0x7f/0xe0 mm/kmsan/kmsan.c:337
  kmem_cache_alloc+0x1c2/0x1e0 mm/slub.c:2766
  reqsk_alloc ./include/net/request_sock.h:87
  inet_reqsk_alloc+0xa4/0x5b0 net/ipv4/tcp_input.c:6200
  cookie_v6_check+0x4f4/0x1b50 net/ipv6/syncookies.c:169
  tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989
  tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298
  tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487
  ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279
  NF_HOOK ./include/linux/netfilter.h:257
  ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322
  dst_input ./include/net/dst.h:492
  ip6_rcv_finish net/ipv6/ip6_input.c:69
  NF_HOOK ./include/linux/netfilter.h:257
  ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203
  __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208
  __netif_receive_skb net/core/dev.c:4246
  process_backlog+0x667/0xba0 net/core/dev.c:4866
  napi_poll net/core/dev.c:5268
  net_rx_action+0xc95/0x1590 net/core/dev.c:5333
  __do_softirq+0x485/0x942 kernel/softirq.c:284
 ==================================================================

Similar error is reported for cookie_v4_check().

Fixes: 58d607d3e5 ("tcp: provide skb->hash to synack packets")
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-18 11:22:51 -07:00
Reshetova, Elena
633547973f net: convert sk_buff.users from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 07:39:07 -07:00
Eric Dumazet
5d2ed0521a tcp: Namespaceify sysctl_tcp_timestamps
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 10:53:29 -04:00
Eric Dumazet
f930103421 tcp: Namespaceify sysctl_tcp_sack
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 10:53:28 -04:00
Eric Dumazet
eed29f17f0 tcp: add a struct net parameter to tcp_parse_options()
We want to move some TCP sysctls to net namespaces in the future.

tcp_window_scaling, tcp_sack and tcp_timestamps being fetched
from tcp_parse_options(), we need to pass an extra parameter.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 10:53:28 -04:00
Eric Dumazet
9a568de481 tcp: switch TCP TS option (RFC 7323) to 1ms clock
TCP Timestamps option is defined in RFC 7323

Traditionally on linux, it has been tied to the internal
'jiffies' variable, because it had been a cheap and good enough
generator.

For TCP flows on the Internet, 1 ms resolution would be much better
than 4ms or 10ms (HZ=250 or HZ=100 respectively)

For TCP flows in the DC, Google has used usec resolution for more
than two years with great success [1]

Receive size autotuning (DRS) is indeed more precise and converges
faster to optimal window size.

This patch converts tp->tcp_mstamp to a plain u64 value storing
a 1 usec TCP clock.

This choice will allow us to upstream the 1 usec TS option as
discussed in IETF 97.

[1] https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf

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>
2017-05-17 16:06:01 -04:00
Eric Dumazet
84b114b984 tcp: randomize timestamps on syncookies
Whole point of randomization was to hide server uptime, but an attacker
can simply start a syn flood and TCP generates 'old style' timestamps,
directly revealing server jiffies value.

Also, TSval sent by the server to a particular remote address vary
depending on syncookies being sent or not, potentially triggering PAWS
drops for innocent clients.

Lets implement proper randomization, including for SYNcookies.

Also we do not need to export sysctl_tcp_timestamps, since it is not
used from a module.

In v2, I added Florian feedback and contribution, adding tsoff to
tcp_get_cookie_sock().

v3 removed one unused variable in tcp_v4_connect() as Florian spotted.

Fixes: 95a22caee3 ("tcp: randomize tcp timestamp offsets for each connection")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Tested-by: Florian Westphal <fw@strlen.de>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-05 12:00:11 -04:00
Jason A. Donenfeld
fe62d05b29 syncookies: use SipHash in place of SHA1
SHA1 is slower and less secure than SipHash, and so replacing syncookie
generation with SipHash makes natural sense. Some BSDs have been doing
this for several years in fact.

The speedup should be similar -- and even more impressive -- to the
speedup from the sequence number fix in this series.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09 13:58:57 -05:00
Florian Westphal
95a22caee3 tcp: randomize tcp timestamp offsets for each connection
jiffies based timestamps allow for easy inference of number of devices
behind NAT translators and also makes tracking of hosts simpler.

commit ceaa1fef65 ("tcp: adding a per-socket timestamp offset")
added the main infrastructure that is needed for per-connection ts
randomization, in particular writing/reading the on-wire tcp header
format takes the offset into account so rest of stack can use normal
tcp_time_stamp (jiffies).

So only two items are left:
 - add a tsoffset for request sockets
 - extend the tcp isn generator to also return another 32bit number
   in addition to the ISN.

Re-use of ISN generator also means timestamps are still monotonically
increasing for same connection quadruple, i.e. PAWS will still work.

Includes fixes from Eric Dumazet.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02 12:49:59 -05:00
Lorenzo Colitti
e2d118a1cb net: inet: Support UID-based routing in IP protocols.
- Use the UID in routing lookups made by protocol connect() and
  sendmsg() functions.
- Make sure that routing lookups triggered by incoming packets
  (e.g., Path MTU discovery) take the UID of the socket into
  account.
- For packets not associated with a userspace socket, (e.g., ping
  replies) use UID 0 inside the user namespace corresponding to
  the network namespace the socket belongs to. This allows
  all namespaces to apply routing and iptables rules to
  kernel-originated traffic in that namespaces by matching UID 0.
  This is better than using the UID of the kernel socket that is
  sending the traffic, because the UID of kernel sockets created
  at namespace creation time (e.g., the per-processor ICMP and
  TCP sockets) is the UID of the user that created the socket,
  which might not be mapped in the namespace.

Tested: compiles allnoconfig, allyesconfig, allmodconfig
Tested: https://android-review.googlesource.com/253302
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-04 14:45:23 -04:00
Eric Dumazet
02a1d6e7a6 net: rename NET_{ADD|INC}_STATS_BH()
Rename NET_INC_STATS_BH() to __NET_INC_STATS()
and NET_ADD_STATS_BH() to __NET_ADD_STATS()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 22:48:24 -04:00
Linus Torvalds
1200b6809d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Highlights:

   1) Support more Realtek wireless chips, from Jes Sorenson.

   2) New BPF types for per-cpu hash and arrap maps, from Alexei
      Starovoitov.

   3) Make several TCP sysctls per-namespace, from Nikolay Borisov.

   4) Allow the use of SO_REUSEPORT in order to do per-thread processing
   of incoming TCP/UDP connections.  The muxing can be done using a
   BPF program which hashes the incoming packet.  From Craig Gallek.

   5) Add a multiplexer for TCP streams, to provide a messaged based
      interface.  BPF programs can be used to determine the message
      boundaries.  From Tom Herbert.

   6) Add 802.1AE MACSEC support, from Sabrina Dubroca.

   7) Avoid factorial complexity when taking down an inetdev interface
      with lots of configured addresses.  We were doing things like
      traversing the entire address less for each address removed, and
      flushing the entire netfilter conntrack table for every address as
      well.

   8) Add and use SKB bulk free infrastructure, from Jesper Brouer.

   9) Allow offloading u32 classifiers to hardware, and implement for
      ixgbe, from John Fastabend.

  10) Allow configuring IRQ coalescing parameters on a per-queue basis,
      from Kan Liang.

  11) Extend ethtool so that larger link mode masks can be supported.
      From David Decotigny.

  12) Introduce devlink, which can be used to configure port link types
      (ethernet vs Infiniband, etc.), port splitting, and switch device
      level attributes as a whole.  From Jiri Pirko.

  13) Hardware offload support for flower classifiers, from Amir Vadai.

  14) Add "Local Checksum Offload".  Basically, for a tunneled packet
      the checksum of the outer header is 'constant' (because with the
      checksum field filled into the inner protocol header, the payload
      of the outer frame checksums to 'zero'), and we can take advantage
      of that in various ways.  From Edward Cree"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits)
  bonding: fix bond_get_stats()
  net: bcmgenet: fix dma api length mismatch
  net/mlx4_core: Fix backward compatibility on VFs
  phy: mdio-thunder: Fix some Kconfig typos
  lan78xx: add ndo_get_stats64
  lan78xx: handle statistics counter rollover
  RDS: TCP: Remove unused constant
  RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket
  net: smc911x: convert pxa dma to dmaengine
  team: remove duplicate set of flag IFF_MULTICAST
  bonding: remove duplicate set of flag IFF_MULTICAST
  net: fix a comment typo
  ethernet: micrel: fix some error codes
  ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it
  bpf, dst: add and use dst_tclassid helper
  bpf: make skb->tc_classid also readable
  net: mvneta: bm: clarify dependencies
  cls_bpf: reset class and reuse major in da
  ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c
  ldmvsw: Add ldmvsw.c driver code
  ...
2016-03-19 10:05:34 -07:00
Peter Zijlstra
25528213fe tags: Fix DEFINE_PER_CPU expansions
$ make tags
  GEN     tags
ctags: Warning: drivers/acpi/processor_idle.c:64: null expansion of name pattern "\1"
ctags: Warning: drivers/xen/events/events_2l.c:41: null expansion of name pattern "\1"
ctags: Warning: kernel/locking/lockdep.c:151: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:133: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:135: null expansion of name pattern "\1"
ctags: Warning: kernel/workqueue.c:323: null expansion of name pattern "\1"
ctags: Warning: net/ipv4/syncookies.c:53: null expansion of name pattern "\1"
ctags: Warning: net/ipv6/syncookies.c:44: null expansion of name pattern "\1"
ctags: Warning: net/rds/page.c:45: null expansion of name pattern "\1"

Which are all the result of the DEFINE_PER_CPU pattern:

  scripts/tags.sh:200:	'/\<DEFINE_PER_CPU([^,]*, *\([[:alnum:]_]*\)/\1/v/'
  scripts/tags.sh:201:	'/\<DEFINE_PER_CPU_SHARED_ALIGNED([^,]*, *\([[:alnum:]_]*\)/\1/v/'

The below cures them. All except the workqueue one are within reasonable
distance of the 80 char limit. TJ do you have any preference on how to
fix the wq one, or shall we just not care its too long?

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Nikolay Borisov
12ed8244ed ipv4: Namespaceify tcp syncookies sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:10 -05:00
David Ahern
6dd9a14e92 net: Allow accepted sockets to be bound to l3mdev domain
Allow accepted sockets to derive their sk_bound_dev_if setting from the
l3mdev domain in which the packets originated. A sysctl setting is added
to control the behavior which is similar to sk_mark and
sysctl_tcp_fwmark_accept.

This effectively allow a process to have a "VRF-global" listen socket,
with child sockets bound to the VRF device in which the packet originated.
A similar behavior can be achieved using sk_mark, but a solution using marks
is incomplete as it does not handle duplicate addresses in different L3
domains/VRFs. Allowing sockets to inherit the sk_bound_dev_if from l3mdev
domain provides a complete solution.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-18 14:43:38 -05:00
Eric Dumazet
45f6fad84c ipv6: add complete rcu protection around np->opt
This patch addresses multiple problems :

UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions
while socket is not locked : Other threads can change np->opt
concurrently. Dmitry posted a syzkaller
(http://github.com/google/syzkaller) program desmonstrating
use-after-free.

Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock()
and dccp_v6_request_recv_sock() also need to use RCU protection
to dereference np->opt once (before calling ipv6_dup_options())

This patch adds full RCU protection to np->opt

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-02 23:37:16 -05:00
Eric Dumazet
ed53d0ab76 net: shrink struct sock and request_sock by 8 bytes
One 32bit hole is following skc_refcnt, use it.
skc_incoming_cpu can also be an union for request_sock rcv_wnd.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-12 19:28:22 -07:00
Eric Dumazet
a1a5344ddb tcp: avoid two atomic ops for syncookies
inet_reqsk_alloc() is used to allocate a temporary request
in order to generate a SYNACK with a cookie. Then later,
syncookie validation also uses a temporary request.

These paths already took a reference on listener refcount,
we can avoid a couple of atomic operations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 02:45:27 -07:00
Eric Dumazet
3f684b4b1f tcp: cookie_init_sequence() cleanups
Some common IPv4/IPv6 code can be factorized.
Also constify cookie_init_sequence() socket argument.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 16:53:09 -07:00
Yuchung Cheng
0f1c28ae74 tcp: usec resolution SYN/ACK RTT
Currently SYN/ACK RTT is measured in jiffies. For LAN the SYN/ACK
RTT is often measured as 0ms or sometimes 1ms, which would affect
RTT estimation and min RTT samping used by some congestion control.

This patch improves SYN/ACK RTT to be usec resolution if platform
supports it. While the timestamping of SYN/ACK is done in request
sock, the RTT measurement is carefully arranged to avoid storing
another u64 timestamp in tcp_sock.

For regular handshake w/o SYNACK retransmission, the RTT is sampled
right after the child socket is created and right before the request
sock is released (tcp_check_req() in tcp_minisocks.c)

For Fast Open the child socket is already created when SYN/ACK was
sent, the RTT is sampled in tcp_rcv_state_process() after processing
the final ACK an right before the request socket is released.

If the SYN/ACK was retransmistted or SYN-cookie was used, we rely
on TCP timestamps to measure the RTT. The sample is taken at the
same place in tcp_rcv_state_process() after the timestamp values
are validated in tcp_validate_incoming(). Note that we do not store
TS echo value in request_sock for SYN-cookies, because the value
is already stored in tp->rx_opt used by tcp_ack_update_rtt().

One side benefit is that the RTT measurement now happens before
initializing congestion control (of the passive side). Therefore
the congestion control can use the SYN/ACK RTT.

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>
2015-09-21 16:19:01 -07:00
Eric Dumazet
b80c0e7858 tcp: get_cookie_sock() consolidation
IPv4 and IPv6 share same implementation of get_cookie_sock(),
and there is no point inlining it.

We add tcp_ prefix to the common helper name and export it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-07 15:19:52 -07:00