IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 IPVS: stopping backup sync thread 23193 ... INFO: task syz-executor2:4482 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-executor2 D20000 4482 4476 0x00000000 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 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3557 __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 cgrp_css_online+0x93/0x1b0 net/core/netprio_cgroup.c:161 online_css+0xf6/0x2e0 kernel/cgroup/cgroup.c:4679 css_create kernel/cgroup/cgroup.c:4750 [inline] cgroup_apply_control_enable+0x710/0xbc0 kernel/cgroup/cgroup.c:2916 cgroup_mkdir+0x56f/0xfc0 kernel/cgroup/cgroup.c:4938 kernfs_iop_mkdir+0x153/0x1e0 fs/kernfs/dir.c:1099 vfs_mkdir+0x390/0x600 fs/namei.c:3800 SYSC_mkdirat fs/namei.c:3823 [inline] SyS_mkdirat fs/namei.c:3807 [inline] SYSC_mkdir fs/namei.c:3834 [inline] SyS_mkdir+0x220/0x2a0 fs/namei.c:3832 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453cd7 RSP: 002b:00007ffdc324a2a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 000000000000019f RCX: 0000000000453cd7 RDX: 0000000000000011 RSI: 00000000000001ff RDI: 00007ffdc324b020 RBP: 00007ffdc324a950 R08: 0000000000000000 R09: 0000000000000005 R10: 0000000000000064 R11: 0000000000000202 R12: 00007ffdc324a2d0 R13: 0000000000000013 R14: 0000000000000000 R15: 0000000000001380 Showing all locks held in the system: 2 locks held by khungtaskd/869: #0: (rcu_read_lock){....}, at: [<00000000af0dc6b9>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000af0dc6b9>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000658f981f>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4311: #0: (&f->f_pos_lock){+.+.}, at: [<00000000a75102eb>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4401: #0: (&tty->ldisc_sem){++++}, at: [<00000000a8847aaf>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006412dc90>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4402: #0: (&tty->ldisc_sem){++++}, at: [<00000000a8847aaf>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006412dc90>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4403: #0: (&tty->ldisc_sem){++++}, at: [<00000000a8847aaf>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006412dc90>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4404: #0: (&tty->ldisc_sem){++++}, at: [<00000000a8847aaf>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006412dc90>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4405: #0: (&tty->ldisc_sem){++++}, at: [<00000000a8847aaf>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006412dc90>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4406: #0: (&tty->ldisc_sem){++++}, at: [<00000000a8847aaf>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006412dc90>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4407: #0: (&tty->ldisc_sem){++++}, at: [<00000000a8847aaf>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000006412dc90>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 4 locks held by syz-executor2/4482: #0: (sb_writers#11){.+.+}, at: [<00000000c51596d8>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#11){.+.+}, at: [<00000000c51596d8>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<000000005511bc33>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<000000005511bc33>] filename_create+0x192/0x520 fs/namei.c:3625 #2: (cgroup_mutex){+.+.}, at: [<000000002acbd4fa>] cgroup_kn_lock_live+0x29e/0x580 kernel/cgroup/cgroup.c:1535 #3: (rtnl_mutex){+.+.}, at: [<000000000fa69480>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 3 locks held by kworker/1:2/5133: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)){+.+.}, at: [<00000000a2cc8008>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cgroup_mutex){+.+.}, at: [<00000000726890e6>] css_killed_work_fn+0x93/0x5c0 kernel/cgroup/cgroup.c:4967 3 locks held by kworker/0:10/13236: #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000080576f9e>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000080576f9e>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000080576f9e>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000080576f9e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((addr_chk_work).work){+.+.}, at: [<00000000a2cc8008>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<000000000fa69480>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 3 locks held by kworker/0:12/13238: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000080576f9e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)){+.+.}, at: [<00000000a2cc8008>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cgroup_mutex){+.+.}, at: [<00000000726890e6>] css_killed_work_fn+0x93/0x5c0 kernel/cgroup/cgroup.c:4967 1 lock held by syz-executor1/23194: #0: (ipvs->sync_mutex){+.+.}, at: [<0000000064f692d3>] do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393 2 locks held by syz-executor1/23195: #0: (rtnl_mutex){+.+.}, at: [<000000000fa69480>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 #1: (ipvs->sync_mutex){+.+.}, at: [<00000000193d0857>] do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388 1 lock held by ipvs-b:13:0/23193: #0: (rtnl_mutex){+.+.}, at: [<000000000fa69480>] 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