TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. ------------[ cut here ]------------ lockdep bfs error:-1 WARNING: CPU: 1 PID: 24593 at kernel/locking/lockdep.c:1960 print_bfs_bug+0x130/0x1e0 kernel/locking/lockdep.c:1960 Modules linked in: CPU: 1 PID: 24593 Comm: syz-executor.1 Not tainted 5.9.0-rc7-next-20200930-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:print_bfs_bug+0x130/0x1e0 kernel/locking/lockdep.c:1960 Code: e2 08 00 74 2c 48 c7 c7 c0 7f a6 8d e8 49 51 01 00 66 90 85 db 75 05 5b 5d 41 5c c3 89 ee 48 c7 c7 20 e8 ab 88 e8 7b e5 c0 06 <0f> 0b 5b 5d 41 5c c3 0f 0b e8 62 82 e9 06 85 c0 74 d7 48 c7 c0 38 RSP: 0018:ffffc90000da8078 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88802b6a4200 RSI: ffffffff815df1a5 RDI: fffff520001b5001 RBP: 00000000ffffffff R08: 0000000000000001 R09: ffff8880ae520f8b R10: 0000000000000000 R11: 207065646b636f6c R12: ffff88802b6a4200 R13: dffffc0000000000 R14: 0000000000000007 R15: 0000000000000000 FS: 00007f38215ec700(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3152f000 CR3: 000000003b2c6000 CR4: 00000000001526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_irq_usage+0x6b4/0xc60 kernel/locking/lockdep.c:2585 check_prev_add kernel/locking/lockdep.c:2823 [inline] check_prevs_add kernel/locking/lockdep.c:2944 [inline] validate_chain kernel/locking/lockdep.c:3562 [inline] __lock_acquire+0x2873/0x56d0 kernel/locking/lockdep.c:4796 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5398 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 alloc_object lib/debugobjects.c:239 [inline] __debug_object_init+0x5c6/0xd10 lib/debugobjects.c:548 debug_hrtimer_init kernel/time/hrtimer.c:414 [inline] debug_init kernel/time/hrtimer.c:473 [inline] hrtimer_init+0x23/0x2b0 kernel/time/hrtimer.c:1431 tcp_init_xmit_timers+0x7b/0xc0 net/ipv4/tcp_timer.c:784 tcp_create_openreq_child+0x68c/0x1700 net/ipv4/tcp_minisocks.c:502 tcp_v6_syn_recv_sock+0x192/0x2240 net/ipv6/tcp_ipv6.c:1270 tcp_get_cookie_sock+0xca/0x620 net/ipv4/syncookies.c:209 cookie_v6_check+0x14bd/0x2210 net/ipv6/syncookies.c:252 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1139 [inline] tcp_v6_do_rcv+0xf50/0x1290 net/ipv6/tcp_ipv6.c:1468 tcp_v6_rcv+0x3140/0x3480 net/ipv6/tcp_ipv6.c:1679 ip6_protocol_deliver_rcu+0x2e8/0x1680 net/ipv6/ip6_input.c:433 ip6_input_finish+0x7f/0x160 net/ipv6/ip6_input.c:474 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:483 dst_input include/net/dst.h:449 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ipv6_rcv+0x28e/0x3c0 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5302 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5416 process_backlog+0x2e1/0x8e0 net/core/dev.c:6306 napi_poll net/core/dev.c:6750 [inline] net_rx_action+0x587/0x1320 net/core/dev.c:6820 __do_softirq+0x203/0xab6 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x9b/0xd0 arch/x86/kernel/irq_64.c:77 do_softirq kernel/softirq.c:343 [inline] do_softirq+0x154/0x1b0 kernel/softirq.c:330 __local_bh_enable_ip+0x196/0x1f0 kernel/softirq.c:195 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:731 [inline] ip6_finish_output2+0x953/0x1770 net/ipv6/ip6_output.c:118 __ip6_finish_output net/ipv6/ip6_output.c:143 [inline] __ip6_finish_output+0x447/0xab0 net/ipv6/ip6_output.c:128 ip6_finish_output+0x34/0x1f0 net/ipv6/ip6_output.c:153 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x1db/0x520 net/ipv6/ip6_output.c:176 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip6_xmit+0x1258/0x1e80 net/ipv6/ip6_output.c:280 inet6_csk_xmit+0x339/0x610 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x18cc/0x3760 net/ipv4/tcp_output.c:1404 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline] tcp_write_xmit+0xead/0x5c70 net/ipv4/tcp_output.c:2684 do_tcp_sendpages+0x12ba/0x1c70 net/ipv4/tcp.c:1069 tls_push_sg+0x1e6/0x770 net/tls/tls_main.c:124 tls_tx_records+0x3a5/0x730 net/tls/tls_sw.c:405 tls_push_record+0x16f5/0x3050 net/tls/tls_sw.c:782 bpf_exec_tx_verdict+0xd82/0x11a0 net/tls/tls_sw.c:802 tls_sw_do_sendpage+0xa1b/0xf70 net/tls/tls_sw.c:1214 tls_sw_sendpage+0x9d/0xe0 net/tls/tls_sw.c:1278 inet_sendpage+0xd0/0x140 net/ipv4/af_inet.c:831 kernel_sendpage net/socket.c:3653 [inline] sock_sendpage+0xe5/0x140 net/socket.c:944 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x3dc/0x830 fs/splice.c:542 splice_from_pipe fs/splice.c:577 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:723 do_splice_from fs/splice.c:744 [inline] direct_splice_actor+0x10c/0x170 fs/splice.c:913 splice_direct_to_actor+0x38c/0x980 fs/splice.c:868 do_splice_direct+0x1b3/0x280 fs/splice.c:956 do_sendfile+0x55f/0xd40 fs/read_write.c:1247 __do_sys_sendfile64 fs/read_write.c:1308 [inline] __se_sys_sendfile64 fs/read_write.c:1294 [inline] __x64_sys_sendfile64+0x1ed/0x220 fs/read_write.c:1294 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45dd99 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f38215ebc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000027ec0 RCX: 000000000045dd99 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000008 RBP: 000000000118c010 R08: 0000000000000000 R09: 0000000000000000 R10: 0000800100020001 R11: 0000000000000246 R12: 000000000118bfd4 R13: 00007ffda80c4fcf R14: 00007f38215ec9c0 R15: 000000000118bfd4