INFO: task kworker/u4:5:141 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:5 state:D stack:23688 pid:141 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
rwsem_down_write_slowpath+0xc3f/0x1020 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1b9/0x200 kernel/locking/rwsem.c:1574
f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
f2fs_write_inode+0x3b7/0x4a0 fs/f2fs/inode.c:810
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x720/0xee0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:1997
wb_writeback+0x472/0xbe0 fs/fs-writeback.c:2107
wb_check_background_flush fs/fs-writeback.c:2177 [inline]
wb_do_writeback fs/fs-writeback.c:2265 [inline]
wb_workfn+0xb8e/0xe60 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Showing all locks held in the system:
4 locks held by kworker/u4:0/11:
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffff88807de2e0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88807aca1398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
#3: ffff88807aca1398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
3 locks held by kworker/u4:1/13:
#0: ffff88814c522138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88814c522138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc90000127d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000127d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffffffff8e3bfe48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xce/0x1550 net/ipv6/addrconf.c:4181
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:4/56:
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc90001577d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90001577d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffff888026d880e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88807bd1d398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
#3: ffff88807bd1d398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
4 locks held by kworker/u4:5/141:
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc90002dd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90002dd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffff888030ea40e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff888024509398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
#3: ffff888024509398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
2 locks held by kworker/1:2/788:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc90003877d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90003877d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
3 locks held by kworker/u4:6/1075:
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc9000440fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000440fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2:
ffffffff8e3bfe48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
4 locks held by kworker/u4:7/3501:
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc9000ccd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000ccd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffff88802f3a80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff888020f29398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
#3: ffff888020f29398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
4 locks held by kworker/u4:9/4807:
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc9000f8d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000f8d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffff88805eb980e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88805eae1398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
#3: ffff88805eae1398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
2 locks held by getty/5530:
#0: ffff88802d4ce0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
6 locks held by syz.0.17/5934:
4 locks held by syz.1.18/5957:
5 locks held by syz.2.19/5985:
5 locks held by syz.3.20/6005:
5 locks held by syz.4.21/6032:
4 locks held by kworker/u4:10/6057:
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc900037b7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900037b7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffff88801ef8e0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88805ce31398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
#3: ffff88805ce31398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
5 locks held by syz.5.22/6065:
4 locks held by kworker/u4:11/6082:
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801ce77538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc900038a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900038a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffff8880769140e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88807ed69398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2185 [inline]
#3: ffff88807ed69398 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x511/0x6e0 fs/f2fs/segment.c:453
4 locks held by syz.6.23/6094:
3 locks held by syz-executor/6100:
#0: ffffffff8e3bfe48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8e3bfe48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
#1: ffff88807c3a9468 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50
#2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by dhcpcd/6130:
#0: ffff888070d32620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888070d32620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
#0: ffff888070d32620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1421
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 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+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6094 Comm: syz.6.23 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_preemption_disabled+0x18/0x110 lib/smp_processor_id.c:14
Code: c0 7b 1c 8b eb 0c 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 05 dd ca 7f 75 65 8b 0d d2 ca 7f 75 f7 c1 ff ff ff 7f 74 1f
RSP: 0018:ffffc900038f6928 EFLAGS: 00000286
RAX: 799bb42770e24f00 RBX: ffffffff81b5700e RCX: 0000000000000000
RDX: ffff88802ba40000 RSI: ffffffff8b1c7bc0 RDI: ffffffff8b1c7b80
RBP: ffffc900038f6a68 R08: ffffea0001caa9b7 R09: 1ffffd4000395536
R10: dffffc0000000000 R11: fffff94000395537 R12: 1ffff9200071ed34
R13: dffffc0000000000 R14: ffffea0001caa980 R15: 0000000000000001
FS: 0000555563df7500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563df354c660 CR3: 000000005f9fc000 CR4: 00000000003506e0
Call Trace:
<TASK>
rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:700
rcu_read_unlock include/linux/rcupdate.h:815 [inline]
filemap_get_entry+0x2fe/0x3f0 mm/filemap.c:1870
__filemap_get_folio+0x7c/0xbe0 mm/filemap.c:1897
pagecache_get_page+0x2a/0x250 mm/folio-compat.c:99
find_get_page_flags include/linux/pagemap.h:711 [inline]
f2fs_grab_cache_page+0x28/0x340 fs/f2fs/f2fs.h:2804
__get_node_page+0x171/0xf50 fs/f2fs/node.c:1475
is_alive fs/f2fs/gc.c:1116 [inline]
gc_data_segment fs/f2fs/gc.c:1545 [inline]
do_garbage_collect+0x2070/0x66e0 fs/f2fs/gc.c:1781
f2fs_gc+0xc75/0x25a0 fs/f2fs/gc.c:1884
f2fs_balance_fs+0x566/0x6e0 fs/f2fs/segment.c:455
f2fs_map_blocks+0x3608/0x4080 fs/f2fs/data.c:1792
f2fs_expand_inode_data+0x669/0xa00 fs/f2fs/file.c:1851
f2fs_fallocate+0x41c/0x8f0 fs/f2fs/file.c:1954
vfs_fallocate+0x585/0x6f0 fs/open.c:324
ioctl_preallocate fs/ioctl.c:291 [inline]
file_ioctl fs/ioctl.c:331 [inline]
do_vfs_ioctl+0x19ef/0x1cc0 fs/ioctl.c:850
__do_sys_ioctl fs/ioctl.c:869 [inline]
__se_sys_ioctl+0x83/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb60bd9ce59
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:00007fff67ce3b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb60c015fa0 RCX: 00007fb60bd9ce59
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007fb60be32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb60c015fac R14: 00007fb60c015fa0 R15: 00007fb60c015fa0
</TASK>