TCP: request_sock_TCP: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. INFO: task syz-executor6:7728 blocked for more than 120 seconds. Not tainted 4.16.0+ #380 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D20368 7728 4474 0x00000004 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x8fb/0x1ef0 kernel/sched/core.c:3490 schedule+0xf5/0x430 kernel/sched/core.c:3549 io_schedule+0x1c/0x70 kernel/sched/core.c:5169 __blkdev_direct_IO_simple+0x7bd/0xf30 fs/block_dev.c:241 blkdev_direct_IO+0xd0d/0x10a0 fs/block_dev.c:428 generic_file_read_iter+0x4cc/0x2980 mm/filemap.c:2343 blkdev_read_iter+0x105/0x170 fs/block_dev.c:1928 call_read_iter include/linux/fs.h:1776 [inline] generic_file_splice_read+0x3f9/0x7b0 fs/splice.c:307 do_splice_to+0x10a/0x160 fs/splice.c:880 splice_direct_to_actor+0x242/0x820 fs/splice.c:952 do_splice_direct+0x29b/0x3c0 fs/splice.c:1061 do_sendfile+0x5c9/0xe80 fs/read_write.c:1440 SYSC_sendfile64 fs/read_write.c:1495 [inline] SyS_sendfile64+0xbd/0x160 fs/read_write.c:1487 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4552d9 RSP: 002b:00007f927ebbbc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f927ebbc6d4 RCX: 00000000004552d9 RDX: 0000000020000080 RSI: 0000000000000018 RDI: 0000000000000018 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000102000004 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004c5 R14: 00000000006fa318 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/877: #0: 00000000c73b5564 (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 00000000c73b5564 (rcu_read_lock){....}, at: watchdog+0x1d6/0xd70 kernel/hung_task.c:249 #1: 00000000a4553991 (tasklist_lock){.+.+}, at: debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4300: #0: 0000000039d0d61e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x165/0x1a0 fs/file.c:766 2 locks held by getty/4390: #0: 000000004bd3832b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e06c8941 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4391: #0: 00000000210b742a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008cef4352 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4392: #0: 000000007d38bf01 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000086a74e89 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4393: #0: 0000000008660b18 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c0af5627 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4394: #0: 000000009eca2340 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000f392e9a6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4395: #0: 00000000daf107ed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005ab09de0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4396: #0: 00000000247fd9b9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000458798dc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 877 Comm: khungtaskd Not tainted 4.16.0+ #380 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1a7/0x27d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1e0/0x220 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x969/0xd70 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.16.0+ #380 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:enqueue_task kernel/sched/core.c:741 [inline] RIP: 0010:activate_task+0x170/0x2c0 kernel/sched/core.c:765 RSP: 0018:ffff8801db107538 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8801d9e94240 RCX: 1ffff1003b3d28c1 RDX: 0000000000000009 RSI: ffff8801d9e94240 RDI: ffff8801db12c5c0 RBP: ffff8801db107560 R08: ffff88021fff805c R09: ffff88021fff8048 R10: ffff88021fff805d R11: ffff88021fff8050 R12: ffff8801db12c5c0 R13: ffff8801d9e94608 R14: ffff8801db107720 R15: ffff8801db107720 FS: 0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd566774140 CR3: 00000001b5d1e000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ttwu_activate kernel/sched/core.c:1636 [inline] ttwu_do_activate+0xd5/0x1f0 kernel/sched/core.c:1695 ttwu_queue kernel/sched/core.c:1840 [inline] try_to_wake_up+0xa1f/0x1300 kernel/sched/core.c:2053 wake_up_process+0x10/0x20 kernel/sched/core.c:2126 process_timeout+0x31/0x40 kernel/time/timer.c:1730 call_timer_fn+0x228/0x820 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7ee/0xb70 kernel/time/timer.c:1666 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:525 [inline] smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffff8801d9ed7cb0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff12 RAX: dffffc0000000000 RBX: 1ffff1003b3daf99 RCX: 0000000000000000 RDX: 1ffffffff10a2558 RSI: 0000000000000001 RDI: ffffffff88512ac0 RBP: ffff8801d9ed7cb0 R08: ffffed003b6246c3 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801d9ed7d68 R14: ffffffff88ee37a0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xbf/0x430 arch/x86/kernel/process.c:354 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:345 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:151 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:241 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:346 start_secondary+0x40a/0x590 arch/x86/kernel/smpboot.c:267 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 Code: 00 48 89 de 4c 89 e7 41 ff 55 08 48 83 c4 08 5b 41 5c 41 5d 41 5e 5d c3 4c 89 e7 89 55 dc e8 68 a8 ff ff 8b 55 dc e9 5d ff ff ff <48> c7 c7 a0 12 85 88 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48