linux-stable.git/include/net/request_sock.h, branch linux-6.9.y

tcp: Clear req->syncookie in reqsk_alloc().

2024-03-20T02:35:59+00:00

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 695751e31a63 ("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: 695751e31a63 ("bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check().")
Reported-by: syzkaller 
Reported-by: Eric Dumazet 
Closes: https://lore.kernel.org/bpf/CANn89iKdN9c+C_2JAUbc+VY3DDQjAQukMtiBbormAmAk9CdvQA@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/r/20240315224710.55209-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski

bpf: tcp: Handle BPF SYN Cookie in skb_steal_sock().

2024-01-23T22:40:24+00:00

We will support arbitrary SYN Cookie with BPF.

If BPF prog validates ACK and kfunc allocates a reqsk, it will
be carried to TCP stack as skb->sk with req->syncookie 1.  Also,
the reqsk has its listener as req->rsk_listener with no refcnt
taken.

When the TCP stack looks up a socket from the skb, we steal
inet_reqsk(skb->sk)->rsk_listener in skb_steal_sock() so that
the skb will be processed in cookie_v[46]_check() with the
listener.

Note that we do not clear skb->sk and skb->destructor so that we
can carry the reqsk to cookie_v[46]_check().

Signed-off-by: Kuniyuki Iwashima 
Link: https://lore.kernel.org/r/20240115205514.68364-4-kuniyu@amazon.com
Signed-off-by: Martin KaFai Lau 
Signed-off-by: Alexei Starovoitov

tcp: Move skb_steal_sock() to request_sock.h

2024-01-23T22:40:23+00:00

We will support arbitrary SYN Cookie with BPF.

If BPF prog validates ACK and kfunc allocates a reqsk, it will
be carried to TCP stack as skb->sk with req->syncookie 1.

In skb_steal_sock(), we need to check inet_reqsk(sk)->syncookie
to see if the reqsk is created by kfunc.  However, inet_reqsk()
is not available in sock.h.

Let's move skb_steal_sock() to request_sock.h.

While at it, we refactor skb_steal_sock() so it returns early if
skb->sk is NULL to minimise the following patch.

Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20240115205514.68364-3-kuniyu@amazon.com
Signed-off-by: Martin KaFai Lau 
Signed-off-by: Alexei Starovoitov

tcp: Use BPF timeout setting for SYN ACK RTO

2022-02-02T14:45:18+00:00

When setting RTO through BPF program, some SYN ACK packets were unaffected
and continued to use TCP_TIMEOUT_INIT constant. This patch adds timeout
option to struct request_sock. Option is initialized with TCP_TIMEOUT_INIT
and is reassigned through BPF using tcp_timeout_init call. SYN ACK
retransmits now use newly added timeout option.

Signed-off-by: Akhmat Karakotov 
Acked-by: Martin KaFai Lau 

v2:
	- Add timeout option to struct request_sock. Do not call
	  tcp_timeout_init on every syn ack retransmit.

v3:
	- Use unsigned long for min. Bound tcp_timeout_init to TCP_RTO_MAX.

v4:
	- Refactor duplicate code by adding reqsk_timeout function.
Signed-off-by: David S. Miller

tcp: bpf: Optionally store mac header in TCP_SAVE_SYN

2020-08-24T21:35:00+00:00

This patch is adapted from Eric's patch in an earlier discussion [1].

The TCP_SAVE_SYN currently only stores the network header and
tcp header.  This patch allows it to optionally store
the mac header also if the setsockopt's optval is 2.

It requires one more bit for the "save_syn" bit field in tcp_sock.
This patch achieves this by moving the syn_smc bit next to the is_mptcp.
The syn_smc is currently used with the TCP experimental option.  Since
syn_smc is only used when CONFIG_SMC is enabled, this patch also puts
the "IS_ENABLED(CONFIG_SMC)" around it like the is_mptcp did
with "IS_ENABLED(CONFIG_MPTCP)".

The mac_hdrlen is also stored in the "struct saved_syn"
to allow a quick offset from the bpf prog if it chooses to start
getting from the network header or the tcp header.

[1]: https://lore.kernel.org/netdev/CANn89iLJNWh6bkH7DNhy_kmcAexuUCccqERqe7z2QsvPhGrYPQ@mail.gmail.com/

Suggested-by: Eric Dumazet 
Signed-off-by: Martin KaFai Lau 
Signed-off-by: Alexei Starovoitov 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/bpf/20200820190123.2886935-1-kafai@fb.com

tcp: Use a struct to represent a saved_syn

2020-08-24T21:34:59+00:00

The TCP_SAVE_SYN has both the network header and tcp header.
The total length of the saved syn packet is currently stored in
the first 4 bytes (u32) of an array and the actual packet data is
stored after that.

A later patch will add a bpf helper that allows to get the tcp header
alone from the saved syn without the network header.  It will be more
convenient to have a direct offset to a specific header instead of
re-parsing it.  This requires to separately store the network hdrlen.
The total header length (i.e. network + tcp) is still needed for the
current usage in getsockopt.  Although this total length can be obtained
by looking into the tcphdr and then get the (th->doff << 2), this patch
chooses to directly store the tcp hdrlen in the second four bytes of
this newly created "struct saved_syn".  By using a new struct, it can
give a readable name to each individual header length.

Signed-off-by: Martin KaFai Lau 
Signed-off-by: Alexei Starovoitov 
Reviewed-by: Eric Dumazet 
Acked-by: John Fastabend 
Link: https://lore.kernel.org/bpf/20200820190014.2883694-1-kafai@fb.com

tcp: rename request_sock cookie_ts bit to syncookie

2020-07-31T23:55:32+00:00

Nowadays output function has a 'synack_type' argument that tells us when
the syn/ack is emitted via syncookies.

The request already tells us when timestamps are supported, so check
both to detect special timestamp for tcp option encoding is needed.

We could remove cookie_ts altogether, but a followup patch would
otherwise need to adjust function signatures to pass 'want_cookie' to
mptcp core.

This way, the 'existing' bit can be used.

Suggested-by: Eric Dumazet 
Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

net: add {READ|WRITE}_ONCE() annotations on ->rskq_accept_head

2019-10-10T04:34:31+00:00

reqsk_queue_empty() is called from inet_csk_listen_poll() while
other cpus might write ->rskq_accept_head value.

Use {READ|WRITE}_ONCE() to avoid compiler tricks
and potential KCSAN splats.

Fixes: fff1f3001cc5 ("tcp: add a spinlock to protect struct request_sock_queue")
Signed-off-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

inet: clear num_timeout reqsk_alloc()

2019-06-19T21:46:57+00:00

KMSAN caught uninit-value in tcp_create_openreq_child() [1]
This is caused by a recent change, combined by the fact
that TCP cleared num_timeout, num_retrans and sk fields only
when a request socket was about to be queued.

Under syncookie mode, a temporary request socket is used,
and req->num_timeout could contain garbage.

Lets clear these three fields sooner, there is really no
point trying to defer this and risk other bugs.

[1]

BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
CPU: 1 PID: 13357 Comm: syz-executor591 Not tainted 5.2.0-rc4+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x162/0x2d0 mm/kmsan/kmsan.c:611
 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304
 tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
 tcp_v6_syn_recv_sock+0x761/0x2d80 net/ipv6/tcp_ipv6.c:1152
 tcp_get_cookie_sock+0x16e/0x6b0 net/ipv4/syncookies.c:209
 cookie_v6_check+0x27e0/0x29a0 net/ipv6/syncookies.c:252
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
 tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
 ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
 dst_input include/net/dst.h:439 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
 __netif_receive_skb net/core/dev.c:5095 [inline]
 process_backlog+0x721/0x1410 net/core/dev.c:5906
 napi_poll net/core/dev.c:6329 [inline]
 net_rx_action+0x738/0x1940 net/core/dev.c:6395
 __do_softirq+0x4ad/0x858 kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
 ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
 dst_output include/net/dst.h:433 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
 tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:601 [inline]
 sock_close+0x156/0x490 net/socket.c:1273
 __fput+0x4c9/0xba0 fs/file_table.c:280
 ____fput+0x37/0x40 fs/file_table.c:313
 task_work_run+0x22e/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:185 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
 prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x401d50
Code: 01 f0 ff ff 0f 83 40 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d dd 8d 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 14 0d 00 00 c3 48 83 ec 08 e8 7a 02 00 00
RSP: 002b:00007fff1cf58cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000401d50
RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000004a9050 R08: 0000000020000040 R09: 000000000000001c
R10: 0000000020004004 R11: 0000000000000246 R12: 0000000000402ef0
R13: 0000000000402f80 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline]
 kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:160
 kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177
 kmem_cache_alloc+0x534/0xb00 mm/slub.c:2781
 reqsk_alloc include/net/request_sock.h:84 [inline]
 inet_reqsk_alloc+0xa8/0x600 net/ipv4/tcp_input.c:6384
 cookie_v6_check+0xadb/0x29a0 net/ipv6/syncookies.c:173
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
 tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
 ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
 dst_input include/net/dst.h:439 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
 __netif_receive_skb net/core/dev.c:5095 [inline]
 process_backlog+0x721/0x1410 net/core/dev.c:5906
 napi_poll net/core/dev.c:6329 [inline]
 net_rx_action+0x738/0x1940 net/core/dev.c:6395
 __do_softirq+0x4ad/0x858 kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
 ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
 dst_output include/net/dst.h:433 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
 tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:601 [inline]
 sock_close+0x156/0x490 net/socket.c:1273
 __fput+0x4c9/0xba0 fs/file_table.c:280
 ____fput+0x37/0x40 fs/file_table.c:313
 task_work_run+0x22e/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:185 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
 prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Fixes: 336c39a03151 ("tcp: undo init congestion window on false SYNACK timeout")
Signed-off-by: Eric Dumazet 
Cc: Yuchung Cheng 
Cc: Neal Cardwell 
Cc: Soheil Hassas Yeganeh 
Reported-by: syzbot 
Acked-by: Soheil Hassas Yeganeh 
Acked-by: Yuchung Cheng 
Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

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 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman