INFO: task syz-executor:4861 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:21456 pid: 4861 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
 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191
 sync_inodes_sb+0x1b3/0x920 fs/fs-writeback.c:2781
 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+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: 0033:0x7f539bba9497
RSP: 002b:00007fffd8e0d1e8 EFLAGS: 00000246
 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f539bc2908c RCX: 00007f539bba9497
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffd8e0d2a0
RBP: 00007fffd8e0d2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffd8e0e330
R13: 00007f539bc2908c R14: 0000000000017bca R15: 00007fffd8e0e370
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: 
ffff88802a306d38
 (
(wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: 
ffffc90000cc7d00
 (
(work_completion)(&(&ifa->dad_work)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: 
ffffffff8d238988
 (
rtnl_mutex
){+.+.}-{3:3}
, at: addrconf_dad_work+0xc4/0x1520 net/ipv6/addrconf.c:4110
4 locks held by kworker/u4:0/9:
 #0: 
ffff8881425f0938
 ((wq_completion)writeback
){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: 
ffff88805e320650
 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: 
ffff88805a88c468
 (
&xfs_nondir_ilock_class
){++++}-{3:3}
, at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578
1 lock held by khungtaskd/27:
 #0: 
ffffffff8c11c760
 (
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:1/144:
 #0: 
ffff8881425f0938
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000171fd00 ((work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: 
ffff88807904e650
 (
sb_internal
#2
){.+.+}-{0:0}
, at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: 
ffff8880722a3568
 (
&xfs_nondir_ilock_class
){++++}-{3:3}
, at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578
3 locks held by kworker/u4:2/154:
 #0: 
ffff888016879138
 (
(wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: 
ffffc90002037d00
 ((linkwatch_work).work
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: 
ffffffff8d238988
 (
rtnl_mutex
){+.+.}-{3:3}
, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
4 locks held by kworker/u4:3/1168:
 #0: 
ffff8881425f0938
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90004a97d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffff888079876650 (sb_internal
#2
){.+.+}-{0:0}
, at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: 
ffff8880722a1768
 (
&xfs_nondir_ilock_class
){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578
2 locks held by getty/3946:
 #0: 
ffff88814d079098
 (
&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
5 locks held by kworker/0:21/4311:
2 locks held by kworker/0:23/4315:
 #0: 
ffff888016872138
 (
(wq_completion)rcu_gp
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: 
ffffc9000326fd00
 (
(work_completion)(&rew.rew_work)
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
4 locks held by kworker/u4:5/4347:
 #0: 
ffff8881425f0938
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: 
ffffc9000334fd00
 ((work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: 
ffff88807ad5e650
 (
sb_internal
#2
){.+.+}-{0:0}
, at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: 
ffff88805a88e268
 (
&xfs_nondir_ilock_class
){++++}-{3:3}
, at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578
4 locks held by kworker/u4:6/4348:
 #0: 
ffff8881425f0938
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: 
ffffc9000307fd00
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: 
ffff88807ae56650
 (
sb_internal
#2
){.+.+}-{0:0}
, at: native_irq_enable arch/x86/include/asm/irqflags.h:45 [inline]
, at: arch_local_irq_enable arch/x86/include/asm/irqflags.h:80 [inline]
, at: arch_local_irq_restore arch/x86/include/asm/irqflags.h:140 [inline]
, at: console_trylock_spinning+0x2c6/0x350 kernel/printk/printk.c:1902
 #3: 
ffff88801e221720 (&local->rx_path_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:369 [inline]
ffff88801e221720 (&local->rx_path_lock){+.-.}-{2:2}, at: ieee80211_rx_handlers+0xe6/0x8470 net/mac80211/rx.c:3924
2 locks held by syz-executor/4861:
 #0: 
ffff8880798760e0 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff8881479e47d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2779
2 locks held by syz-executor/5137:
 #0: 
ffff88807904e0e0
 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff88801fb2a7d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2779
2 locks held by syz-executor/5168:
 #0: 
ffff88807ae560e0
 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffff88801fb387d8 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2779
2 locks held by syz-executor/5207:
 #0: 
ffff88805e3200e0
 (
&type->s_umount_key
#54
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: 
ffff88801fb3e7d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2779
2 locks held by syz-executor/5264:
 #0: ffff88807ad5e0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffff88801fc747d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2779
2 locks held by syz-executor/5320:
 #0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
 #1: 
ffffffff8c1211e8
 (
rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 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 10/02/2025
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: 4347 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: writeback wb_workfn (flush-7:4)
RIP: 0010:io_serial_out+0x78/0xb0 drivers/tty/serial/8250/8250_port.c:468
Code: 3f 32 fd 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 b0 a7 76 fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 44 89 f9 80 e1 07 38 c1 7c aa 4c 89 ff
RSP: 0018:ffffc9000334dc68 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000669b78 R11: 1ffff92000669b78 R12: dffffc0000000000
R13: 1ffffffff2c20f30 R14: ffffffff963eb840 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e256113a38 CR3: 000000002a23c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 uart_console_write+0xaa/0x100 drivers/tty/serial/serial_core.c:1981
 serial8250_console_write+0xbb5/0xf80 drivers/tty/serial/8250/8250_port.c:3386
 call_console_drivers kernel/printk/printk.c:-1 [inline]
 console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 __xfs_printk fs/xfs/xfs_message.c:24 [inline]
 xfs_buf_alert_ratelimited+0x21d/0x230 fs/xfs/xfs_message.c:139
 xfs_buf_ioerror_alert fs/xfs/xfs_buf.c:1338 [inline]
 xfs_buf_read_map+0x535/0x950 fs/xfs/xfs_buf.c:817
 xfs_trans_read_buf_map+0x1d4/0x8a0 fs/xfs/xfs_trans_buf.c:289
 xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [inline]
 xfs_read_agf+0x23c/0x500 fs/xfs/libxfs/xfs_alloc.c:3011
 xfs_alloc_read_agf+0xc1/0xb40 fs/xfs/libxfs/xfs_alloc.c:3044
 xfs_alloc_pagf_init+0x8d/0x100 fs/xfs/libxfs/xfs_alloc.c:2811
 xfs_bmap_longest_free_extent+0x11c/0x210 fs/xfs/libxfs/xfs_bmap.c:3240
 xfs_bmap_btalloc_nullfb+0x1f9/0x570 fs/xfs/libxfs/xfs_bmap.c:3309
 xfs_bmap_btalloc+0xbc3/0x1ec0 fs/xfs/libxfs/xfs_bmap.c:3647
 xfs_bmapi_allocate+0x49b/0xe40 fs/xfs/libxfs/xfs_bmap.c:-1
 xfs_bmapi_convert_delalloc+0x655/0xd90 fs/xfs/libxfs/xfs_bmap.c:4636
 xfs_convert_blocks fs/xfs/xfs_aops.c:245 [inline]
 xfs_map_blocks+0x954/0x1320 fs/xfs/xfs_aops.c:366
 iomap_writepage_map fs/iomap/buffered-io.c:1320 [inline]
 iomap_do_writepage+0x649/0x2120 fs/iomap/buffered-io.c:1485
 write_cache_pages+0x984/0xfa0 mm/page-writeback.c:2277
 iomap_writepages+0x5a/0x210 fs/iomap/buffered-io.c:1516
 xfs_vm_writepages+0x129/0x180 fs/xfs/xfs_aops.c:488
 do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386
 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
 writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1940
 wb_writeback+0x443/0xb90 fs/fs-writeback.c:2114
 wb_do_writeback fs/fs-writeback.c:2257 [inline]
 wb_workfn+0x423/0xe60 fs/fs-writeback.c:2298
 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>