NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task kworker/u4:3:379 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:3 D25408 379 2 0x80000000 Workqueue: events_unbound flush_to_ldisc Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 flush_to_ldisc+0x3d/0x390 drivers/tty/tty_buffer.c:500 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 process_scheduled_works kernel/workqueue.c:2212 [inline] worker_thread+0x750/0xe40 kernel/workqueue.c:2301 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task login:8137 blocked for more than 140 seconds. Not tainted 4.19.103-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. login D25048 8137 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782 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 __flush_work+0x49f/0x870 kernel/workqueue.c:2926 flush_work+0x18/0x20 kernel/workqueue.c:2947 tty_buffer_flush_work+0x16/0x19 drivers/tty/tty_buffer.c:613 n_tty_read+0xb1a/0x1b70 drivers/tty/n_tty.c:2197 tty_read+0x193/0x2a0 drivers/tty/tty_io.c:867 __vfs_read+0x114/0x800 fs/read_write.c:416 vfs_read+0x194/0x3d0 fs/read_write.c:452 ksys_read+0x14f/0x2d0 fs/read_write.c:579 __do_sys_read fs/read_write.c:589 [inline] __se_sys_read fs/read_write.c:587 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:587 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f48c0321310 Code: Bad RIP value. RSP: 002b:00007fff6c61e598 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f48c0321310 RDX: 00000000000001ff RSI: 00007fff6c61e800 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007f48c0c04700 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff6c61e800 R13: 0000000000000000 R14: 0000000000000001 R15: 000000000060b798 Showing all locks held in the system: 3 locks held by kworker/u4:2/86: #0: 00000000beb5a885 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9647 [inline] #0: 00000000beb5a885 (&rq->lock){-.-.}, at: pick_next_task_fair+0xfae/0x1580 kernel/sched/fair.c:6819 #1: 00000000beb5a885 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1817 [inline] #1: 00000000beb5a885 (&rq->lock){-.-.}, at: attach_tasks kernel/sched/fair.c:7402 [inline] #1: 00000000beb5a885 (&rq->lock){-.-.}, at: load_balance+0xa95/0x21a0 kernel/sched/fair.c:8699 #2: 000000002ebc95e8 (key#13){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] #2: 000000002ebc95e8 (key#13){+...}, at: batadv_nc_purge_paths+0xd8/0x3a0 net/batman-adv/network-coding.c:453 3 locks held by kworker/u4:3/379: #0: 000000002814fde4 ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000002814fde4 ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000002814fde4 ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000002814fde4 ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000002814fde4 ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000002814fde4 ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000002814fde4 ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 00000000e954d9f5 ((work_completion)(&buf->work)){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 #2: 00000000f9727a55 (&buf->lock){+.+.}, at: flush_to_ldisc+0x3d/0x390 drivers/tty/tty_buffer.c:500 1 lock held by khungtaskd/1073: #0: 00000000dc8cc924 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/8016: #0: 00000000474c5a69 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by login/8137: #0: 000000001771fa56 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000006439ce81 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8138: #0: 0000000024a1fb0c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000db36eff1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8139: #0: 00000000e4522963 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000050bae37f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8140: #0: 000000005cc5a0b9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000c56144f1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8141: #0: 00000000a60fd452 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000040855d8c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8142: #0: 000000006f5262b1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000df4de5e8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8143: #0: 000000008b0f8f1d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000004945b41c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by syz-executor.3/28062: #0: 000000001771fa56 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000f9727a55 (&buf->lock){+.+.}, at: tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1073 Comm: khungtaskd Not tainted 4.19.103-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+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 86 Comm: kworker/u4:2 Not tainted 4.19.103-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:trace_lock_release include/trace/events/lock.h:58 [inline] RIP: 0010:lock_release+0x4d0/0xa30 kernel/locking/lockdep.c:3921 Code: c4 90 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65 8b 05 d3 23 af 7e 83 f8 3f 0f 87 cb 02 00 00 89 c0 48 0f a3 05 70 f1 7a 08 <0f> 83 b1 fc ff ff 65 ff 05 53 90 af 7e 4c 8b 35 44 ad 74 08 4d 85 RSP: 0018:ffff8880a9ae7c18 EFLAGS: 00000093 RAX: 0000000000000001 RBX: 1ffff1101535cf89 RCX: ffffffff87387c31 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a9af287c RBP: ffff8880a9ae7cd0 R08: 0000000000000000 R09: ffffed1015d24733 R10: ffffed1015d24732 R11: ffff8880ae923993 R12: ffffffff88f934e0 R13: ffffffff8738799a R14: ffff8880a9af2000 R15: ffff8880a9ae7ca8 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000010eb000 CR3: 000000009f739000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:247 [inline] rcu_read_unlock include/linux/rcupdate.h:681 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:423 [inline] batadv_nc_worker+0x225/0x760 net/batman-adv/network-coding.c:730 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415