INFO: task syz-executor:4185 blocked for more than 140 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:21136 pid: 4185 ppid:     1 flags:0x00004004
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
 wb_wait_for_completion+0x171/0x290 fs/fs-writeback.c:191
 sync_inodes_sb+0x1bd/0x950 fs/fs-writeback.c:2787
 sync_filesystem+0x16d/0x220 fs/sync.c:64
 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+0x42d/0x4e0 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: 0033:0x7fe0131b19d7
RSP: 002b:00007ffdc7408df8 EFLAGS: 00000246
 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe013246050 RCX: 00007fe0131b19d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdc7408eb0
RBP: 00007ffdc7408eb0 R08: 00007ffdc7409eb0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc7409f40
R13: 00007fe013246050 R14: 000000000002336a R15: 00007ffdc7409f80
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: 
ffffffff8c31eaa0
 (
rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:1/144:
4 locks held by kworker/u4:2/154:
5 locks held by kworker/u4:3/1183:
 #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc90005027d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8d430c50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
 #3: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock_unregistering net/core/dev.c:11646 [inline]
 #3: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x165/0x3c0 net/core/dev.c:11684
 #4: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #4: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
2 locks held by getty/3946:
 #0: 
ffff88802be95098
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900021ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by syz-executor/4185:
 #0: ffff88805f27c0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff888147c287d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
ffff888147c287d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
2 locks held by kworker/0:6/4231:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900031efd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
2 locks held by kworker/u4:5/4237:
2 locks held by syz-executor/4965:
 #0: ffff88807a9040e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffff888147cd07d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff888147cd07d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
4 locks held by kworker/u4:8/5208:
2 locks held by syz-executor/5339:
 #0: ffff888074fdc0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffff888147cd67d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff888147cd67d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
3 locks held by kworker/1:17/6002:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc9000336fd00
 (
deferred_process_work
){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}
, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
4 locks held by kworker/u4:9/6315:
2 locks held by syz-executor/6421:
 #0: ffff888053f4a0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffff8880201d47d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8880201d47d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
1 lock held by syz-executor/7544:
 #0: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5681
1 lock held by syz-executor/7546:
 #0: ffffffff8d43cb48 (rtnl_mutex
){+.+.}-{3:3}
, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5681
1 lock held by syz-executor/7547:
 #0: 
ffffffff8d43cb48
 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5681
1 lock held by syz-executor/7549:
 #0: 
ffffffff8d43cb48
 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5681
3 locks held by kworker/u4:12/7680:
 #0: 
ffff888016c79138
 (
(wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000321fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: 
ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251

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

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 02/12/2026
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: 6315 Comm: kworker/u4:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-7:6)
RIP: 0010:hlock_class kernel/locking/lockdep.c:-1 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4711 [inline]
RIP: 0010:__lock_acquire+0x947/0x7d10 kernel/locking/lockdep.c:4962
Code: 00 00 00 e8 cb 1f 61 00 4c 0f a3 35 83 32 c0 0e 73 1a 4b 8d 04 76 c1 e0 06 4c 8d b0 80 bf b5 8f 49 b8 00 00 00 00 00 fc ff df <eb> 2b 49 b8 00 00 00 00 00 fc ff df 48 8b 84 24 90 00 00 00 42 0f
RSP: 0018:ffffc900000078a0 EFLAGS: 00000002
RAX: 0000000000004680 RBX: 0000000000000004 RCX: ffffffff815d0e35
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d40c8
RBP: ffffc90000007af0 R08: dffffc0000000000 R09: 1ffffffff203a819
R10: dffffc0000000000 R11: fffffbfff203a81a R12: ffff88807b102970
R13: ffff88807b102802 R14: ffffffff8fb60600 R15: ffff88807b102970
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd0bdade80 CR3: 0000000024f69000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x62/0x390 lib/debugobjects.c:749
 debug_hrtimer_deactivate kernel/time/hrtimer.c:415 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1653 [inline]
 __hrtimer_run_queues+0x2b9/0xb70 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 50 e7 18 00 fb 31 c0 eb 48 e8 46 e7 18 00 e8 01 2f 5c 08 48 85 db 74 d1 e8 37 e7 18 00 fb 48 c7 c7 e0 35 31 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 68 da 39 60
RSP: 0018:ffffc900042b6520 EFLAGS: 00000293
RAX: ffffffff816039d9 RBX: 0000000000000200 RCX: ffff88807b101dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c3135e0
RBP: ffffc900042b65f0 R08: ffffffff901d41df R09: 1ffffffff203a83b
R10: dffffc0000000000 R11: fffffbfff203a83c R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff92000856ca4
 vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273
 _printk+0xda/0x130 kernel/printk/printk.c:2299
 _udf_err+0x135/0x190 fs/udf/super.c:2365
 udf_bitmap_new_block fs/udf/balloc.c:357 [inline]
 udf_new_block+0x15b9/0x1a90 fs/udf/balloc.c:730
 inode_getblk fs/udf/inode.c:768 [inline]
 udf_get_block+0x11b4/0x4140 fs/udf/inode.c:358
 __mpage_writepage+0x4bc/0x1ac0 fs/mpage.c:564
 write_cache_pages+0x9b7/0x1000 mm/page-writeback.c:2277
 mpage_writepages+0x113/0x290 fs/mpage.c:712
 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386
 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940
 wb_writeback+0x45d/0xbe0 fs/fs-writeback.c:2114
 wb_do_writeback fs/fs-writeback.c:2257 [inline]
 wb_workfn+0x43a/0xf20 fs/fs-writeback.c:2298
 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>