sctp: sctp_transport_update_pmtu: Reported pmtu 508 too low, using default minimum of 512 sctp: sctp_transport_update_pmtu: Reported pmtu 508 too low, using default minimum of 512 sctp: sctp_transport_update_pmtu: Reported pmtu 508 too low, using default minimum of 512 INFO: task kworker/u4:11:3785 blocked for more than 120 seconds. Not tainted 4.15.0-rc2-next-20171207+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:11 D16448 3785 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2800 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3376 schedule+0xf5/0x430 kernel/sched/core.c:3435 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3493 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xaad/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 cleanup_net+0x24c/0xb60 net/core/net_namespace.c:453 process_one_work+0xbfd/0x1bc0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 Showing all locks held in the system: 2 locks held by khungtaskd/672: #0: (rcu_read_lock){....}, at: [<00000000b9bef8ab>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000b9bef8ab>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000006d6acf8b>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 1 lock held by rsyslogd/2970: #0: (&f->f_pos_lock){+.+.}, at: [<000000001cede688>] __fdget_pos+0x131/0x1a0 fs/file.c:765 2 locks held by getty/3052: #0: (&tty->ldisc_sem){++++}, at: [<000000004e0245ba>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff863b18>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3053: #0: (&tty->ldisc_sem){++++}, at: [<000000004e0245ba>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff863b18>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3054: #0: (&tty->ldisc_sem){++++}, at: [<000000004e0245ba>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff863b18>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3055: #0: (&tty->ldisc_sem){++++}, at: [<000000004e0245ba>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff863b18>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3056: #0: (&tty->ldisc_sem){++++}, at: [<000000004e0245ba>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff863b18>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3057: #0: (&tty->ldisc_sem){++++}, at: [<000000004e0245ba>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff863b18>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3058: #0: (&tty->ldisc_sem){++++}, at: [<000000004e0245ba>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff863b18>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 1 lock held by syz-executor2/3320: #0: (rtnl_mutex){+.+.}, at: [<0000000063c47ced>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 4 locks held by kworker/u4:11/3785: #0: ((wq_completion)"%s""netns"){+.+.}, at: [<0000000087d81703>] __write_once_size include/linux/compiler.h:212 [inline] #0: ((wq_completion)"%s""netns"){+.+.}, at: [<0000000087d81703>] atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ((wq_completion)"%s""netns"){+.+.}, at: [<0000000087d81703>] atomic_long_set include/asm-generic/atomic-long.h:57 [inline] #0: ((wq_completion)"%s""netns"){+.+.}, at: [<0000000087d81703>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"%s""netns"){+.+.}, at: [<0000000087d81703>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"%s""netns"){+.+.}, at: [<0000000087d81703>] process_one_work+0xad4/0x1bc0 kernel/workqueue.c:2084 #1: (net_cleanup_work){+.+.}, at: [<000000008a817b5c>] process_one_work+0xb2f/0x1bc0 kernel/workqueue.c:2088 #2: (net_mutex){+.+.}, at: [<0000000079150fd8>] cleanup_net+0x247/0xb60 net/core/net_namespace.c:450 #3: (rtnl_mutex){+.+.}, at: [<0000000063c47ced>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 3 locks held by kworker/0:6/14978: #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000087d81703>] __write_once_size include/linux/compiler.h:212 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000087d81703>] atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000087d81703>] atomic_long_set include/asm-generic/atomic-long.h:57 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000087d81703>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000087d81703>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000087d81703>] process_one_work+0xad4/0x1bc0 kernel/workqueue.c:2084 #1: ((addr_chk_work).work){+.+.}, at: [<000000008a817b5c>] process_one_work+0xb2f/0x1bc0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<0000000063c47ced>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor2/15852: #0: (rtnl_mutex){+.+.}, at: [<0000000063c47ced>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor7/15958: #0: (rtnl_mutex){+.+.}, at: [<0000000063c47ced>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor7/15961: #0: (rtnl_mutex){+.+.}, at: [<0000000063c47ced>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 672 Comm: khungtaskd Not tainted 4.15.0-rc2-next-20171207+ #61 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+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15938 Comm: syz-executor7 Not tainted 4.15.0-rc2-next-20171207+ #61 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:inb arch/x86/include/asm/io.h:348 [inline] RIP: 0010:io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:434 RSP: 0018:ffff8801c1c173e8 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: ffffc90001c88000 RDI: ffffffff880fa9c0 RBP: ffff8801c1c173f8 R08: 0000000000000002 R09: 000000000000000c R10: 0000000000000000 R11: ffffffff87896d20 R12: ffffffff880fa980 R13: 0000000000000020 R14: fffffbfff101f577 R15: fffffbfff101f53a FS: 00007f1ef8fad700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbea91b6000 CR3: 00000001d0aaa000 CR4: 00000000001406f0 DR0: 0000000020001000 DR1: 0000000020001000 DR2: 0000000020001020 DR3: 0000000020000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: serial_in drivers/tty/serial/8250/8250.h:111 [inline] wait_for_xmitr+0x93/0x1e0 drivers/tty/serial/8250/8250_port.c:2033 serial8250_console_putchar+0x1f/0x60 drivers/tty/serial/8250/8250_port.c:3170 uart_console_write+0xac/0xe0 drivers/tty/serial/serial_core.c:1858 serial8250_console_write+0x647/0xa20 drivers/tty/serial/8250/8250_port.c:3236 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590 call_console_drivers kernel/printk/printk.c:1574 [inline] console_unlock+0x788/0xd70 kernel/printk/printk.c:2233 vprintk_emit+0x4ad/0x590 kernel/printk/printk.c:1757 vprintk_default+0x28/0x30 kernel/printk/printk.c:1796 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1829 __dev_set_promiscuity+0x2a4/0x630 net/core/dev.c:6609 __dev_change_flags+0x559/0x990 net/core/dev.c:6826 dev_change_flags+0x88/0x140 net/core/dev.c:6886 dev_ifsioc+0x60d/0x9b0 net/core/dev_ioctl.c:257 dev_ioctl+0x2c2/0xf90 net/core/dev_ioctl.c:566 sock_do_ioctl+0x94/0xb0 net/socket.c:971 sock_ioctl+0x2c2/0x440 net/socket.c:1061 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452a39 RSP: 002b:00007f1ef8facc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1ef8fad700 RCX: 0000000000452a39 RDX: 00000000208a3fe0 RSI: 0000000000008914 RDI: 0000000000000019 RBP: 0000000000a6f880 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 R13: 0000000000a6f7ff R14: 00007f1ef8fad9c0 R15: 0000000000000002 Code: 24 d9 00 00 00 49 8d 7c 24 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 17 41 03 5c 24 40 89 da ec <5b> 0f b6 c0 41 5c 5d c3 e8 88 ad 18 ff eb c2 e8 e1 ad 18 ff eb