INFO: task syz-executor:4765 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:22032 pid: 4765 ppid:     1 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 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+0x426/0x4d0 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: 0033:0x7f2dbe7c3b57
RSP: 002b:00007ffc09ed6fd8 EFLAGS: 00000246
 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f2dbe85364a RCX: 00007f2dbe7c3b57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc09ed7090
RBP: 00007ffc09ed7090 R08: 00007ffc09ed8090 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc09ed8120
R13: 00007f2dbe85364a R14: 0000000000019f9a R15: 00007ffc09ed8160
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u4:0/9:
 #0: 
ffff8881427d0138
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: 
ffffc90000ce7d00
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: 
ffff8880248b4650
 (
sb_internal
#2
){.+.+}-{0:0}
, at: xfs_bmapi_convert_delalloc+0x224/0xda0 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: 
ffff88805acd9768
 (
&xfs_nondir_ilock_class
){++++}-{3:3}
, at: xfs_bmapi_convert_delalloc+0x25b/0xda0 fs/xfs/libxfs/xfs_bmap.c:4578
1 lock held by khungtaskd/27:
 #0: 
ffffffff8c31ef60
 (
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:2/151:
 #0: 
ffff8881427d0138
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: 
ffffc90001847d00
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff888074464650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x224/0xda0 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: ffff88805ad0a668 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x25b/0xda0 fs/xfs/libxfs/xfs_bmap.c:4578
4 locks held by kworker/u4:3/1169:
 #0: ffff8881427d0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900050c7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88802550a650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x224/0xda0 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: ffff88805ad0e9e8 (&xfs_nondir_ilock_class
){++++}-{3:3}
, at: xfs_bmapi_convert_delalloc+0x25b/0xda0 fs/xfs/libxfs/xfs_bmap.c:4578
2 locks held by getty/3944:
 #0: ffff88814cf85098
 (
&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+0x594/0x1a50 drivers/tty/n_tty.c:2158
5 locks held by kworker/0:16/4274:
2 locks held by kworker/0:19/4277:
 #0: 
ffff888016c72138
 (
(wq_completion)rcu_gp
){+.+.}-{0:0}
, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: 
ffffc9000305fd00
 (
(work_completion)(&rew.rew_work)
){+.+.}-{0:0}
, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
4 locks held by kworker/u4:6/4723:
 #0: 
ffff8881427d0138
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: 
ffffc900030dfd00
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88802774c650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x224/0xda0 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: ffff88805ad08868 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x25b/0xda0 fs/xfs/libxfs/xfs_bmap.c:4578
2 locks held by syz-executor/4765:
 #0: ffff8880248b40e0
 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff8880204147d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
2 locks held by syz-executor/4991:
 #0: 
ffff88802774c0e0
 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff8880206a27d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
2 locks held by syz-executor/5027:
 #0: 
ffff8880744640e0
 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff8881470787d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
2 locks held by syz-executor/5081:
 #0: 
ffff88802550a0e0
 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff88814707e7d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
3 locks held by kworker/u4:7/5090:
 #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000370fd00 ((linkwatch_work).work){+.+.}-{0:0}
, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
2 locks held by syz-executor/5150:
 #0: ffff88807dea40e0 (&type->s_umount_key#54
){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff88814708c7d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
){+.+.}-{3:3}, at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785
4 locks held by kworker/u4:8/5173:
 #0: ffff8881427d0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900039dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88807dea4650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x224/0xda0 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: ffff88806e1d80e8 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x25b/0xda0 fs/xfs/libxfs/xfs_bmap.c:4578
2 locks held by syz-executor/5185:
 #0: ffffffff8d44d488 (
rtnl_mutex
){+.+.}-{3:3}
, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695
 #1: 
ffffffff8c3239e8
 (
rcu_state.exp_mutex
){+.+.}-{3:3}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845

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

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 07/24/2026
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+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/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: 23 Comm: kworker/1:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: xfs-buf/loop4 xfs_buf_ioend_work
RIP: 0010:__sanitizer_cov_trace_switch+0x4/0xe0 kernel/kcov.c:312
Code: 77 1e 4a c7 44 02 08 07 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 0f 1f 44 00 00 48 8b 46 08 <48> 8d 48 ff 48 89 c2 48 31 ca 48 39 ca 0f 86 c3 00 00 00 f3 48 0f
RSP: 0018:ffffc90000ddf308 EFLAGS: 00000246
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: ffffffff840ba029 RSI: ffffffff8c94f7c0 RDI: 000000000000005b
RBP: ffffffff8a2be260 R08: ffff888017a28000 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff8a2be260
R13: 0000000000000000 R14: ffffffff8a2be260 R15: 000000000000005b
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055859b245a38 CR3: 000000007527c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 format_decode+0x13b/0x1330 lib/vsprintf.c:2545
 vsnprintf+0xef/0x1c20 lib/vsprintf.c:2763
 sprintf+0xe4/0x140 lib/vsprintf.c:3013
 print_time kernel/printk/printk.c:1274 [inline]
 info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300
 record_print_text kernel/printk/printk.c:1349 [inline]
 console_unlock+0x650/0x10f0 kernel/printk/printk.c:2725
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xda/0x130 kernel/printk/printk.c:2299
 __xfs_printk fs/xfs/xfs_message.c:24 [inline]
 xfs_alert+0x1a7/0x2c0 fs/xfs/xfs_message.c:52
 xfs_buf_verifier_error+0x15f/0x290 fs/xfs/xfs_error.c:412
 xfs_agf_read_verify+0x1d2/0x250 fs/xfs/libxfs/xfs_alloc.c:-1
 xfs_buf_ioend+0x256/0x6a0 fs/xfs/xfs_buf.c:1263
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>