INFO: task syz-executor.4:22164 blocked for more than 143 seconds. Not tainted 5.2.0-rc3+ #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28128 22164 9008 0x00004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x7cb/0x1560 kernel/sched/core.c:3445 schedule+0xa8/0x260 kernel/sched/core.c:3509 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 kthread_stop+0x10b/0x6c0 kernel/kthread.c:559 io_sq_thread_stop fs/io_uring.c:2252 [inline] io_finish_async+0x73/0x140 fs/io_uring.c:2259 io_ring_ctx_free fs/io_uring.c:2770 [inline] io_ring_ctx_wait_and_kill+0x133/0x5d0 fs/io_uring.c:2832 io_uring_release+0x42/0x50 fs/io_uring.c:2840 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:185 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412f61 Code: 84 3e 02 00 00 48 8b 08 48 8b 54 24 70 48 39 d1 0f 85 41 01 00 00 0f b6 48 17 f6 c1 40 0f 85 99 00 00 00 0f b6 0d 63 a7 3a 01 <84> c9 0f 84 80 00 00 00 48 8b 48 20 31 d2 31 db eb 04 48 83 c2 08 RSP: 002b:00007fff7e8e4380 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000412f61 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000001 R08: 000000007bb3173d R09: 000000007bb31741 R10: 00007fff7e8e4460 R11: 0000000000000293 R12: 00000000007609f0 R13: 00000000000771ec R14: 0000000000077219 R15: 000000000075bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1035: #0: 0000000062a15ab5 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5149 2 locks held by rsyslogd/8866: #0: 00000000519d1fb1 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 0000000027bb8f60 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #1: 0000000027bb8f60 (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1560 kernel/sched/core.c:3397 2 locks held by getty/8958: #0: 000000004ed5838f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005f2c9301 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8959: #0: 00000000a0062c67 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000036e3bb6f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8960: #0: 00000000e8cc7258 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000435c6c15 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8961: #0: 00000000f6842001 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ffeda36a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8962: #0: 000000000ea93ba4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006eb83bf3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8963: #0: 00000000a0d0334c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002d7a1df5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8964: #0: 00000000ffcfbd18 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000025b3c648 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1035 Comm: khungtaskd Not tainted 5.2.0-rc3+ #19 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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+0x9b7/0xec0 kernel/hung_task.c:289 kthread+0x354/0x420 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: 11505 Comm: kworker/u4:15 Not tainted 5.2.0-rc3+ #19 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:validate_chain kernel/locking/lockdep.c:2807 [inline] RIP: 0010:__lock_acquire+0x9a3/0x5490 kernel/locking/lockdep.c:3793 Code: 00 0f 84 1b 06 00 00 48 c7 c2 34 bb 80 89 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 c7 c0 34 bb 80 89 83 e0 07 <83> c0 03 38 d0 7c 08 84 d2 0f 85 fb 33 00 00 8b 35 0c b3 29 08 85 RSP: 0018:ffff88805c827aa0 EFLAGS: 00000002 RAX: 0000000000000004 RBX: ffffffff8a2ee6b0 RCX: ffff888062e10cc0 RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff8a2ee6f0 RBP: ffff88805c827c50 R08: 00000000ab8a3367 R09: ffff888062e10d30 R10: ffff888062e10d10 R11: ffff888062e10440 R12: ffff888062e10d08 R13: 0000000045f0341a R14: ffffffff8980bb30 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000090ec8000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303 rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:593 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0x117/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352