INFO: task kworker/0:0:24023 blocked for more than 143 seconds. Not tainted 5.4.0-rc3+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:0 D27048 24023 2 0x80004000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x74b/0xb80 kernel/sched/core.c:4069 schedule+0x131/0x1e0 kernel/sched/core.c:4136 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4195 __mutex_lock_common+0x1411/0x2e20 kernel/locking/mutex.c:1033 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 linkwatch_event+0xe/0x60 net/core/link_watch.c:242 process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269 worker_thread+0xc01/0x1630 kernel/workqueue.c:2415 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.1:27679 blocked for more than 143 seconds. Not tainted 5.4.0-rc3+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28368 27679 7869 0x00004004 Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x74b/0xb80 kernel/sched/core.c:4069 schedule+0x131/0x1e0 kernel/sched/core.c:4136 exp_funnel_lock kernel/rcu/tree_exp.h:308 [inline] synchronize_rcu_expedited+0x535/0x5a0 kernel/rcu/tree_exp.h:817 synchronize_net+0x3b/0x50 net/core/dev.c:9319 __tun_detach+0x706/0x1a90 drivers/net/tun.c:707 tun_detach drivers/net/tun.c:740 [inline] tun_chr_close+0xf1/0x130 drivers/net/tun.c:3448 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413741 Code: 00 b8 2d f8 ff ff 0f 44 c2 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 31 c0 c3 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 31 c3 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 48 c7 07 40 37 41 00 RSP: 002b:00007ffd5e8e0e20 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000413741 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: 00000000440e1f37 R09: 00000000440e1f3b R10: 00007ffd5e8e0f00 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000760f60 R15: 000000000075c07c Showing all locks held in the system: 1 lock held by khungtaskd/1071: #0: ffffffff888d3f80 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 1 lock held by rsyslogd/7738: #0: ffff888098e9f420 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 fs/file.c:801 2 locks held by getty/7828: #0: ffff88809a1af090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7829: #0: ffff8880961a6090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f092e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7830: #0: ffff888093ce5090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f312e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7831: #0: ffff888091170090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7832: #0: ffff88809b93a090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7833: #0: ffff8880a4803090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7834: #0: ffff8880a8684090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f012e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 3 locks held by kworker/0:0/24023: #0: ffff8880aa427d28 ((wq_completion)events){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff8880aa427d28 ((wq_completion)events){+.+.}, at: process_one_work+0x75d/0x10e0 kernel/workqueue.c:2242 #1: ffff8880a9877d78 ((linkwatch_work).work){+.+.}, at: process_one_work+0x79f/0x10e0 kernel/workqueue.c:2244 #2: ffffffff88b04c90 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/0:1/26563: #0: ffff88821626a528 ((wq_completion)ipv6_addrconf){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff88821626a528 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x75d/0x10e0 kernel/workqueue.c:2242 #1: ffff88806f75fd78 ((addr_chk_work).work){+.+.}, at: process_one_work+0x79f/0x10e0 kernel/workqueue.c:2244 #2: ffffffff88b04c90 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.1/27679: #0: ffffffff88b04c90 (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-rc3+ #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+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbb9/0xbd0 kernel/hung_task.c:289 kthread+0x332/0x350 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 CPU: 1 PID: 3901 Comm: udevd Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__fdget+0x1/0x200 fs/file.c:783 Code: 00 e8 d3 fa ff ff 5b 5d c3 55 48 89 e5 53 89 fb e8 04 7f b6 ff 89 df 31 f6 ba 01 00 00 00 e8 b6 fa ff ff 5b 5d c3 0f 1f 00 55 <48> 89 e5 41 57 41 56 41 54 53 50 41 89 fe 49 bc 00 00 00 00 00 fc RSP: 0018:ffff888096177e90 EFLAGS: 00000293 RAX: ffffffff81c7fd35 RBX: 00007ffd5674c2a0 RCX: ffff88809616c400 RDX: 0000000000000000 RSI: 00007ffffffff000 RDI: 000000000000000a RBP: ffff888096177ed8 R08: ffffffff81c7fd1e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00007ffd5674c240 R13: 00007ffffffff000 R14: 00007ffd5674c2a0 R15: 0000000000000008 FS: 00007f69c628b7a0(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f21e7e16710 CR3: 0000000096489000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_sys_epoll_wait fs/eventpoll.c:2304 [inline] __se_sys_epoll_wait fs/eventpoll.c:2301 [inline] __x64_sys_epoll_wait+0x9a/0xb0 fs/eventpoll.c:2301 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f69c599f943 Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24 RSP: 002b:00007ffd5674c148 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f69c599f943 RDX: 0000000000000008 RSI: 00007ffd5674c240 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000001de27a0 R15: 0000000001dd0250