IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 IPVS: stopping backup sync thread 14746 ... INFO: task syz-executor0:4470 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D18936 4470 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 __rwsem_down_write_failed_common+0x7c0/0x1540 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write_nested+0xa6/0x120 kernel/locking/rwsem.c:190 inode_lock_nested include/linux/fs.h:748 [inline] do_rmdir+0x380/0x5f0 fs/namei.c:3907 SYSC_rmdir fs/namei.c:3937 [inline] SyS_rmdir+0x1a/0x20 fs/namei.c:3935 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454607 RSP: 002b:00007ffffddc8828 EFLAGS: 00000202 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 000000000000014c RCX: 0000000000454607 RDX: 0000000000000000 RSI: 00007ffffddc9500 RDI: 00007ffffddc9520 RBP: 00007ffffddc8ed0 R08: 0000000000000000 R09: 0000000000000001 R10: 000000000000000a R11: 0000000000000202 R12: 0000000000000481 R13: 0000000000000481 R14: 0000000000000006 R15: 000000000003be4e Showing all locks held in the system: 3 locks held by kworker/1:1/23: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)#2){+.+.}, at: [<00000000b831875e>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cgroup_mutex){+.+.}, at: [<00000000be516ac5>] css_release_work_fn+0xea/0x940 kernel/cgroup/cgroup.c:4592 2 locks held by khungtaskd/869: #0: (rcu_read_lock){....}, at: [<0000000078a9839c>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<0000000078a9839c>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000005c607ab3>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by rs:main Q:Reg/4308: #0: (&f->f_pos_lock){+.+.}, at: [<000000004c1cbd9c>] __fdget_pos+0x12b/0x190 fs/file.c:765 #1: (sb_writers#4){.+.+}, at: [<00000000cf7d8e1f>] file_start_write include/linux/fs.h:2709 [inline] #1: (sb_writers#4){.+.+}, at: [<00000000cf7d8e1f>] vfs_write+0x407/0x510 fs/read_write.c:543 1 lock held by rsyslogd/4310: #0: (&f->f_pos_lock){+.+.}, at: [<000000004c1cbd9c>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4400: #0: (&tty->ldisc_sem){++++}, at: [<00000000391abe70>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006f1f521a>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4401: #0: (&tty->ldisc_sem){++++}, at: [<00000000391abe70>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006f1f521a>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4402: #0: (&tty->ldisc_sem){++++}, at: [<00000000391abe70>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006f1f521a>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4403: #0: (&tty->ldisc_sem){++++}, at: [<00000000391abe70>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006f1f521a>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4404: #0: (&tty->ldisc_sem){++++}, at: [<00000000391abe70>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006f1f521a>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4405: #0: (&tty->ldisc_sem){++++}, at: [<00000000391abe70>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006f1f521a>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4406: #0: (&tty->ldisc_sem){++++}, at: [<00000000391abe70>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006f1f521a>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by syz-executor0/4470: #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] do_rmdir+0x380/0x5f0 fs/namei.c:3907 2 locks held by syz-executor3/4474: #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] do_rmdir+0x380/0x5f0 fs/namei.c:3907 4 locks held by syz-executor1/4476: #0: (sb_writers#11){.+.+}, at: [<00000000c7260d6c>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#11){.+.+}, at: [<00000000c7260d6c>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<0000000094e32b09>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<0000000094e32b09>] filename_create+0x192/0x520 fs/namei.c:3625 #2: (cgroup_mutex){+.+.}, at: [<00000000bfcee748>] cgroup_kn_lock_live+0x29e/0x580 kernel/cgroup/cgroup.c:1535 #3: (rtnl_mutex){+.+.}, at: [<00000000bcb66ee7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 2 locks held by syz-executor7/4478: #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] do_rmdir+0x380/0x5f0 fs/namei.c:3907 4 locks held by syz-executor2/4479: #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] do_rmdir+0x380/0x5f0 fs/namei.c:3907 #2: (&type->i_mutex_dir_key#3){++++}, at: [<000000005410392e>] inode_lock include/linux/fs.h:713 [inline] #2: (&type->i_mutex_dir_key#3){++++}, at: [<000000005410392e>] vfs_rmdir+0xd6/0x410 fs/namei.c:3848 #3: (cgroup_mutex){+.+.}, at: [<00000000bfcee748>] cgroup_kn_lock_live+0x29e/0x580 kernel/cgroup/cgroup.c:1535 3 locks held by kworker/0:7/6425: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000773f0553>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)#2){+.+.}, at: [<00000000b831875e>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cgroup_mutex){+.+.}, at: [<00000000be516ac5>] css_release_work_fn+0xea/0x940 kernel/cgroup/cgroup.c:4592 2 locks held by syz-executor6/11587: #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#10){.+.+}, at: [<00000000c7260d6c>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000000c31ff86>] do_rmdir+0x380/0x5f0 fs/namei.c:3907 3 locks held by kworker/1:10/12932: #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000773f0553>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000773f0553>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000773f0553>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000773f0553>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((addr_chk_work).work){+.+.}, at: [<00000000b831875e>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<00000000bcb66ee7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor4/14742: #0: (ipvs->sync_mutex){+.+.}, at: [<0000000064c35885>] do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393 2 locks held by syz-executor4/14749: #0: (rtnl_mutex){+.+.}, at: [<00000000bcb66ee7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 #1: (ipvs->sync_mutex){+.+.}, at: [<000000007431ff40>] do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388 1 lock held by syz-executor5/14752: #0: (rtnl_mutex){+.+.}, at: [<0000000073a8432d>] rtnl_lock net/core/rtnetlink.c:74 [inline] #0: (rtnl_mutex){+.+.}, at: [<0000000073a8432d>] rtnetlink_rcv_msg+0x508/0xb10 net/core/rtnetlink.c:4632 1 lock held by ipvs-b:6:0/14746: #0: (rtnl_mutex){+.+.}, at: [<00000000bcb66ee7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 869 Comm: khungtaskd Not tainted 4.16.0-rc7+ #3 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+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 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+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54