IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 IPVS: stopping backup sync thread 16049 ... INFO: task syz-executor3:4194 blocked for more than 120 seconds. Not tainted 4.16.0-rc6+ #282 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D21936 4194 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 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:0000000000a3eb78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 0000000000000183 RCX: 0000000000453cd7 RDX: 0000000000a3f855 RSI: 00000000000001ff RDI: 0000000000a3f8f0 RBP: 0000000000a3f220 R08: 0000000000000000 R09: 0000000000000005 R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000a3eba0 R13: 0000000000000013 R14: 0000000000000000 R15: 0000000000001380 Showing all locks held in the system: 2 locks held by khungtaskd/793: #0: (rcu_read_lock){....}, at: [<00000000865e497f>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000865e497f>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000000966ddd4>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4124: #0: (&tty->ldisc_sem){++++}, at: [<00000000d7510587>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b2007ea9>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4125: #0: (&tty->ldisc_sem){++++}, at: [<00000000d7510587>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b2007ea9>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4126: #0: (&tty->ldisc_sem){++++}, at: [<00000000d7510587>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b2007ea9>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4127: #0: (&tty->ldisc_sem){++++}, at: [<00000000d7510587>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b2007ea9>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4128: #0: (&tty->ldisc_sem){++++}, at: [<00000000d7510587>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b2007ea9>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4129: #0: (&tty->ldisc_sem){++++}, at: [<00000000d7510587>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b2007ea9>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4130: #0: (&tty->ldisc_sem){++++}, at: [<00000000d7510587>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b2007ea9>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 4 locks held by syz-executor3/4194: #0: (sb_writers#11){.+.+}, at: [<0000000049beaef1>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#11){.+.+}, at: [<0000000049beaef1>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<00000000551e0cf3>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<00000000551e0cf3>] filename_create+0x192/0x520 fs/namei.c:3625 #2: (cgroup_mutex){+.+.}, at: [<00000000f2d2ae21>] cgroup_kn_lock_live+0x29e/0x580 kernel/cgroup/cgroup.c:1535 #3: (rtnl_mutex){+.+.}, at: [<00000000bde7cf94>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 2 locks held by syz-executor1/4202: #0: (sb_writers#11){.+.+}, at: [<0000000049beaef1>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#11){.+.+}, at: [<0000000049beaef1>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<00000000551e0cf3>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#4/1){+.+.}, at: [<00000000551e0cf3>] filename_create+0x192/0x520 fs/namei.c:3625 3 locks held by kworker/1:3/4396: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)#2){+.+.}, at: [<0000000040409a98>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cgroup_mutex){+.+.}, at: [<00000000bcb2fe66>] css_release_work_fn+0xea/0x940 kernel/cgroup/cgroup.c:4592 3 locks held by kworker/0:6/6515: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000009a768b71>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)#2){+.+.}, at: [<0000000040409a98>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cgroup_mutex){+.+.}, at: [<00000000bcb2fe66>] css_release_work_fn+0xea/0x940 kernel/cgroup/cgroup.c:4592 3 locks held by kworker/1:10/7984: #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<000000009a768b71>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<000000009a768b71>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<000000009a768b71>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<000000009a768b71>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((addr_chk_work).work){+.+.}, at: [<0000000040409a98>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<00000000bde7cf94>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor2/16048: #0: (ipvs->sync_mutex){+.+.}, at: [<000000008de1ef1f>] do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393 2 locks held by syz-executor2/16050: #0: (rtnl_mutex){+.+.}, at: [<00000000bde7cf94>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 #1: (ipvs->sync_mutex){+.+.}, at: [<00000000265bf661>] do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388 3 locks held by syz-executor4/16042: #0: (sb_writers#10){.+.+}, at: [<00000000b6f4c64c>] file_start_write include/linux/fs.h:2709 [inline] #0: (sb_writers#10){.+.+}, at: [<00000000b6f4c64c>] vfs_write+0x407/0x510 fs/read_write.c:543 #1: (&of->mutex){+.+.}, at: [<0000000002c5fb6f>] kernfs_fop_write+0x208/0x440 fs/kernfs/file.c:307 #2: (cgroup_mutex){+.+.}, at: [<00000000f2d2ae21>] cgroup_kn_lock_live+0x29e/0x580 kernel/cgroup/cgroup.c:1535 1 lock held by syz-executor5/16043: #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor6/16044: #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor0/16046: #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor7/16047: #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#4){++++}, at: [<00000000404bd3cb>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by ipvs-b:8:0/16049: #0: (rtnl_mutex){+.+.}, at: [<00000000bde7cf94>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 793 Comm: khungtaskd Not tainted 4.16.0-rc6+ #282 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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54