syzbot

INFO: task kworker/0:0:7 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0     state:D stack:23960 pid:    7 ppid:     2 flags:0x00004000
Workqueue: events_long flush_old_commits
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
 reiserfs_sync_fs fs/reiserfs/super.c:76 [inline]
 flush_old_commits+0x1fb/0x310 fs/reiserfs/super.c:111
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/0:0/7:
 #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc90000cc7d00
 (
(work_completion)(&(&sbi->old_work)->work)
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff88807c4300e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: 
ffff888147346090
 (
&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
2 locks held by kworker/u4:0/9:
3 locks held by kworker/0:1/13:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31f360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3947:
 #0: ffff88802c45c098 (&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
4 locks held by kworker/1:10/4263:
 #0: 
ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc900033afd00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff88807c1420e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: ffff8881417fc090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
4 locks held by kworker/1:11/4264:
 #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900032efd00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff8880212740e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: ffff88801b5f0090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
4 locks held by kworker/1:13/4266:
 #0: ffff888016c71138
 (
(wq_completion)events_long
){+.+.}-{0:0}
, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc900033cfd00
 (
(work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff88807c3380e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: 
ffff888078ec6090
 (
&sbi->lock
){+.+.}-{3:3}
, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
4 locks held by kworker/1:14/4267:
 #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900033dfd00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff88801eb880e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: ffff88801d4ae090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
4 locks held by kworker/0:17/4320:
 #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000354fd00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff88805db1c0e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: ffff88805cd56090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
5 locks held by syz.0.17/4327:
3 locks held by kworker/u4:6/4329:
2 locks held by syz.1.18/4345:
2 locks held by syz.2.19/4369:
2 locks held by syz.3.20/4385:
2 locks held by syz.4.21/4414:
2 locks held by syz.5.22/4438:
3 locks held by syz-executor/4441:

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4414 Comm: syz.4.21 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5363 [inline]
RIP: 0010:lock_is_held_type+0xbd/0x190 kernel/locking/lockdep.c:5666
Code: 31 e4 49 83 fc 31 73 24 4c 89 ff 4c 89 f6 e8 fa 01 00 00 85 c0 75 2a 49 ff c4 48 63 83 e8 0a 00 00 49 83 c7 28 49 39 c4 7c d8 <eb> 11 48 c7 c7 80 eb 1e 8c 4c 89 e6 e8 22 ca 46 fa eb cb 31 ed eb
RSP: 0018:ffffc900000079d8 EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffff888019bad940 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8c31f420 RDI: ffff888019bae480
RBP: 00000000ffffffff R08: ffffffff8d8a06ef R09: 1ffffffff1b140dd
R10: dffffc0000000000 R11: fffffbfff1b140de R12: 0000000000000003
R13: 0000000000000046 R14: ffffffff8c31f420 R15: ffff888019bae4a8
FS:  00005555645a7500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37a2483e9c CR3: 000000002a0e1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_is_held include/linux/lockdep.h:287 [inline]
 rcu_read_lock_sched_held+0x86/0x110 kernel/rcu/update.c:125
 task_css_set include/linux/cgroup.h:483 [inline]
 task_dfl_cgroup include/linux/cgroup.h:552 [inline]
 cgroup_account_cputime include/linux/cgroup.h:796 [inline]
 update_curr+0x3ca/0x8d0 kernel/sched/fair.c:858
 entity_tick kernel/sched/fair.c:4785 [inline]
 task_tick_fair+0xd6/0xfd0 kernel/sched/fair.c:11475
 scheduler_tick+0x1da/0x4d0 kernel/sched/core.c:5320
 update_process_times+0x1c7/0x200 kernel/time/timer.c:2026
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:console_trylock_spinning+0x301/0x370 kernel/printk/printk.c:1909
Code: 85 db 74 89 e8 e0 e9 18 00 fb 31 c0 eb 48 e8 d6 e9 18 00 e8 11 1b 5d 08 48 85 db 74 d1 e8 c7 e9 18 00 fb 48 c7 c7 a0 3e 31 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 68 2a 5f 60
RSP: 0018:ffffc900045fe1a0 EFLAGS: 00000293
RAX: ffffffff81605f29 RBX: 0000000000000200 RCX: ffff888019bad940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c313ea0
RBP: ffffc900045fe270 R08: ffffffff901d81f7 R09: 1ffffffff203b03e
R10: dffffc0000000000 R11: fffffbfff203b03f R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920008bfc34
 vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273
 _printk+0xda/0x130 kernel/printk/printk.c:2299
 __reiserfs_warning+0x16c/0x1b0 fs/reiserfs/prints.c:290
 reiserfs_read_bitmap_block+0x216/0x680 fs/reiserfs/bitmap.c:1434
 scan_bitmap_block+0x1a8/0xe20 fs/reiserfs/bitmap.c:164
 scan_bitmap fs/reiserfs/bitmap.c:391 [inline]
 allocate_without_wrapping_disk fs/reiserfs/bitmap.c:1161 [inline]
 blocknrs_and_prealloc_arrays_from_search_start fs/reiserfs/bitmap.c:1274 [inline]
 reiserfs_allocate_blocknrs+0x279c/0x4e80 fs/reiserfs/bitmap.c:1375
 reiserfs_new_form_blocknrs fs/reiserfs/reiserfs.h:3341 [inline]
 get_empty_nodes+0x42e/0x920 fs/reiserfs/fix_node.c:879
 fix_nodes+0x1ebc/0x8340 fs/reiserfs/fix_node.c:2662
 reiserfs_paste_into_item+0x60b/0x810 fs/reiserfs/stree.c:2130
 reiserfs_get_block+0x1c3a/0x42a0 fs/reiserfs/inode.c:1077
 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012
 reiserfs_write_begin+0x34b/0x810 fs/reiserfs/inode.c:2790
 generic_perform_write+0x2b6/0x550 mm/filemap.c:3785
 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2173 [inline]
 aio_write+0x54a/0x780 fs/aio.c:1594
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x6cd/0x1380 fs/aio.c:2013
 __do_sys_io_submit fs/aio.c:2072 [inline]
 __se_sys_io_submit+0x19d/0x310 fs/aio.c:2042
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f12d0bf0e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe5ac3f6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007f12d0e69fa0 RCX: 00007f12d0bf0e59
RDX: 0000200000000200 RSI: 0000000000000001 RDI: 00007f12d0e43000
RBP: 00007f12d0c86d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f12d0e69fac R14: 00007f12d0e69fa0 R15: 00007f12d0e69fa0
 </TASK>