INFO: task kworker/u4:1:21 blocked for more than 143 seconds. Not tainted 5.4.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:1 D25608 21 2 0x80004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x909/0x1ee0 kernel/sched/core.c:4078 schedule+0xd9/0x260 kernel/sched/core.c:4145 exp_funnel_lock kernel/rcu/tree_exp.h:308 [inline] synchronize_rcu_expedited+0x57f/0x5f0 kernel/rcu/tree_exp.h:817 synchronize_net+0x3b/0x60 net/core/dev.c:9861 dev_deactivate_many+0x501/0xc10 net/sched/sch_generic.c:1208 __dev_close_many+0x145/0x300 net/core/dev.c:1502 dev_close_many+0x24c/0x6c0 net/core/dev.c:1540 rollback_registered_many+0x42e/0x10d0 net/core/dev.c:8720 unregister_netdevice_many.part.0+0x1b/0x1f0 net/core/dev.c:9906 unregister_netdevice_many+0x3b/0x50 net/core/dev.c:9905 ip6gre_exit_batch_net+0x541/0x760 net/ipv6/ip6_gre.c:1604 ops_exit_list.isra.0+0x10c/0x160 net/core/net_namespace.c:175 cleanup_net+0x538/0xaf0 net/core/net_namespace.c:597 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/1:3:8860 blocked for more than 143 seconds. Not tainted 5.4.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:3 D26936 8860 2 0x80004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x909/0x1ee0 kernel/sched/core.c:4078 schedule+0xd9/0x260 kernel/sched/core.c:4145 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4204 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 addrconf_dad_work+0xad/0x1150 net/ipv6/addrconf.c:4033 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.1:8921 blocked for more than 143 seconds. Not tainted 5.4.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27264 8921 8845 0x00004004 Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x909/0x1ee0 kernel/sched/core.c:4078 schedule+0xd9/0x260 kernel/sched/core.c:4145 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4204 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 cangw_pernet_exit+0x13/0x30 net/can/gw.c:1180 ops_exit_list.isra.0+0xb1/0x160 net/core/net_namespace.c:172 setup_net+0x546/0x8b0 net/core/net_namespace.c:358 copy_net_ns+0x29e/0x520 net/core/net_namespace.c:476 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:103 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:202 ksys_unshare+0x444/0x980 kernel/fork.c:2858 __do_sys_unshare kernel/fork.c:2926 [inline] __se_sys_unshare kernel/fork.c:2924 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2924 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: Bad RIP value. RSP: 002b:00007f780ddfdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045a639 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f780ddfe6d4 R13: 00000000004ca75d R14: 00000000004e29a0 R15: 00000000ffffffff INFO: task syz-executor.0:9003 blocked for more than 144 seconds. Not tainted 5.4.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27512 9003 8843 0x00000004 Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x909/0x1ee0 kernel/sched/core.c:4078 schedule+0xd9/0x260 kernel/sched/core.c:4145 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4204 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 sock_do_ioctl+0x24e/0x2f0 net/socket.c:1051 sock_ioctl+0x3ed/0x790 net/socket.c:1189 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: Bad RIP value. RSP: 002b:00007f7298f76c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000020000040 RSI: 0000001000008912 RDI: 000000000000000b RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7298f776d4 R13: 00000000004c1d6b R14: 00000000004d5cb0 R15: 00000000ffffffff Showing all locks held in the system: 4 locks held by kworker/u4:1/21: #0: ffff8880a99cad28 ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a99cad28 ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a99cad28 ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a99cad28 ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a99cad28 ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8880a99cad28 ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8880a99cad28 ((wq_completion)netns){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2240 #1: ffff8880a9a1fdc0 (net_cleanup_work){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2244 #2: ffffffff89999448 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0xaf0 net/core/net_namespace.c:559 #3: ffffffff899a5740 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/u4:2/220: #0: ffff8880ae934d18 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8880ae934d18 (&rq->lock){-.-.}, at: __schedule+0x232/0x1ee0 kernel/sched/core.c:4026 #1: ffffffff88fabc00 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5833 #2: ffffffff88fabc00 (rcu_read_lock){....}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:405 [inline] #2: ffffffff88fabc00 (rcu_read_lock){....}, at: batadv_nc_worker+0xe3/0x760 net/batman-adv/network-coding.c:718 1 lock held by khungtaskd/1071: #0: ffffffff88fabc00 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5337 2 locks held by rsyslogd/8714: #0: ffff888097f8e8a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: ffffffff88fa1178 (logbuf_lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:951 [inline] #1: ffffffff88fa1178 (logbuf_lock){-.-.}, at: debug_check_no_obj_freed+0xc0/0x43f lib/debugobjects.c:994 2 locks held by getty/8803: #0: ffff88809a74b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f1d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8804: #0: ffff8880a419a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f332e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8805: #0: ffff888092892090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8806: #0: ffff8880a8e40090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8807: #0: ffff8880a9b59090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f2f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8808: #0: ffff88809d139090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8809: #0: ffff88809b313090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f012e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 3 locks held by kworker/1:3/8860: #0: ffff88821659e128 ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff88821659e128 ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88821659e128 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff88821659e128 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff88821659e128 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff88821659e128 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff88821659e128 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2240 #1: ffff88806bff7dc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2244 #2: ffffffff899a5740 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 2 locks held by syz-executor.1/8921: #0: ffffffff89999448 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x27b/0x520 net/core/net_namespace.c:472 #1: ffffffff899a5740 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.0/9003: #0: ffffffff899a5740 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1071 Comm: khungtaskd Not tainted 5.4.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9d0/0xef0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60