INFO: task kworker/1:16:4319 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:16    state:D stack:24776 pid: 4319 ppid:     2 flags:0x00004000
Workqueue: events_long flush_mdb
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbc/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x11f/0x160 kernel/sched/wait_bit.c:117
 lock_buffer include/linux/buffer_head.h:402 [inline]
 hfs_mdb_commit+0x113/0x1110 fs/hfs/mdb.c:271
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task syz-executor:4820 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21504 pid: 4820 ppid:     1 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbc/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x11f/0x160 kernel/sched/wait_bit.c:117
 lock_buffer include/linux/buffer_head.h:402 [inline]
 hfs_mdb_commit+0xadf/0x1110 fs/hfs/mdb.c:325
 hfs_sync_fs+0x11/0x20 fs/hfs/super.c:35
 sync_filesystem+0xe6/0x220 fs/sync.c:56
 generic_shutdown_super+0x6b/0x300 fs/super.c:448
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4fbf5ce1f7
RSP: 002b:00007ffe03097cd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f4fbf64fd7d RCX: 00007f4fbf5ce1f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe03097d90
RBP: 00007ffe03097d90 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe03098e20
R13: 00007f4fbf64fd7d R14: 000000000001d08e R15: 00007ffe03098e60
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/1:1/23:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90000ddfd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/1217:
2 locks held by getty/3946:
 #0: ffff88802bd6b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
2 locks held by kworker/0:4/4198:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90002f7fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/0:5/4241:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90002fdfd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/0:6/4242:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000306fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/0:7/4244:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000307fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/0:9/4247:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900030afd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/1:7/4308:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000321fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/1:11/4313:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000325fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/1:16/4319:
 #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900032bfd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
1 lock held by syz-executor/4820:
 #0: ffff888072c280e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5102:
 #0: ffff8881468780e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5124:
 #0: ffff8880289500e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5152:
 #0: ffff88801af940e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5176:
 #0: ffff88802bc1a0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5204:
 #0: ffff8880580fc0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5233:
 #0: ffff888056b5c0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5269:
 #0: ffff8880692300e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5296:
 #0: ffff8880692fc0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5323:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4356 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:mark_lock+0x0/0x320 kernel/locking/lockdep.c:4552
Code: 38 c1 7c 90 48 c7 c7 48 69 69 8d e8 2a 84 5f 00 4c 89 f7 41 89 d9 e9 79 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <55> 41 57 41 56 41 55 41 54 53 50 89 d5 49 89 f6 48 89 fb 49 bd 00
RSP: 0018:ffffc900033ff778 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880183e0ad0 RCX: dffffc0000000000
RDX: 0000000000000008 RSI: ffff8880183e0b40 RDI: ffff8880183e0000
RBP: ffffc900033ff9d0 R08: dffffc0000000000 R09: fffffbfff1ff5439
R10: fffffbfff1ff5439 R11: 1ffffffff1ff5438 R12: ffff8880183e0b60
R13: ffff8880183e0000 R14: ffffffff8f9933b8 R15: ffff8880183e0b40
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd79b92194b CR3: 000000005fbf4000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mark_usage kernel/locking/lockdep.c:4512 [inline]
 __lock_acquire+0xd5a/0x7c60 kernel/locking/lockdep.c:4966
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:369 [inline]
 batadv_nc_purge_paths+0xe7/0x3b0 net/batman-adv/network-coding.c:446
 batadv_nc_worker+0x327/0x5c0 net/batman-adv/network-coding.c:726
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>