INFO: task kworker/u8:218:3145 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:218 state:D stack:21280 pid:3145 tgid:3145 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
f2fs_down_write fs/f2fs/f2fs.h:2407 [inline]
f2fs_down_write_trace fs/f2fs/checkpoint.c:180 [inline]
f2fs_issue_checkpoint+0x437/0x790 fs/f2fs/checkpoint.c:2104
f2fs_balance_fs_bg+0x574/0x9d0 fs/f2fs/segment.c:545
f2fs_write_node_pages+0x158/0x700 fs/f2fs/node.c:2251
do_writepages+0x32e/0x550 mm/page-writeback.c:2554
__writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1762
writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2054
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2130
wb_writeback+0x46a/0xb70 fs/fs-writeback.c:2241
wb_check_old_data_flush fs/fs-writeback.c:2345 [inline]
wb_do_writeback fs/fs-writeback.c:2398 [inline]
wb_workfn+0xb52/0xf60 fs/fs-writeback.c:2426
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/37:
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:213/3140:
4 locks held by kworker/u8:218/3145:
#0: ffff88801e6cc138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801e6cc138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc9000fe27c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc9000fe27c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff88803e9520d0 (&type->s_umount_key#92){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff888063725a98 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2407 [inline]
#3: ffff888063725a98 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write_trace fs/f2fs/checkpoint.c:180 [inline]
#3: ffff888063725a98 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_issue_checkpoint+0x437/0x790 fs/f2fs/checkpoint.c:2104
1 lock held by udevd/5372:
2 locks held by getty/5758:
#0: ffff888038b970a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by udevd/6007:
#0: ffff888022761670 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
#0: ffff888022761670 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854
#1: ffff888022761840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
#1: ffff888022761840 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
#1: ffff888022761840 (mapping.invalidate_lock){++++}-{4:4}, at: force_page_cache_ra+0x263/0x2e0 mm/readahead.c:364
2 locks held by udevd/6020:
#0: ffff888038d88480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888039548c38 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff888039548c38 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3762 [inline]
#1: ffff888039548c38 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3858
5 locks held by syz.2.128/6963:
9 locks held by syz-executor/7869:
2 locks held by udevd/8795:
1 lock held by syz.0.444/9450:
2 locks held by syz.9.447/9438:
4 locks held by syz.1.452/9461:
#0: ffff8880242d0480 (sb_writers#24){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1158
#1: ffff888063052d90 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#1: ffff888063052d90 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: exfat_file_write_iter+0x12d/0x7d0 fs/exfat/file.c:643
#2: ffff88803d78e0d8 (&sbi->s_lock#2){+.+.}-{4:4}, at: exfat_get_block+0x1ba/0x1b10 fs/exfat/inode.c:262
#3: ffff88803d78e158 (&sbi->bitmap_lock){+.+.}-{4:4}, at: exfat_alloc_cluster+0x11d/0xc10 fs/exfat/fatent.c:388
6 locks held by dhcpcd-run-hook/9468:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3140 Comm: kworker/u8:213 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:_raw_spin_unlock_irqrestore+0x0/0x80 kernel/locking/spinlock.c:193
Code: 3c 00 00 cc e8 11 b8 0b f6 5b c3 cc cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 56 53 48 89 f3 49 89 fe 48 83 c7 18 48 8b 74 24 10
RSP: 0018:ffffc9000fd87618 EFLAGS: 00000002
RAX: 0000000000000002 RBX: ffffc9000fd87668 RCX: ffffffff995a0403
RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffff888019c3ac00
RBP: ffffc9000fd876d8 R08: ffff888019c3ac57 R09: 1ffff1100338758a
R10: dffffc0000000000 R11: ffffed100338758b R12: 1ffff92001fb0ecd
R13: 0000000000000246 R14: ffff888019c3ac00 R15: ffffc9000fd87660
FS: 0000000000000000(0000) GS:ffff888126435000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0a83d34286 CR3: 000000000dbba000 CR4: 00000000003526f0
Call Trace:
raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:97 [inline]
rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x17a/0x400 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:45 [inline]
pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402
__text_poke+0x2d3/0x9a0 arch/x86/kernel/alternative.c:2575
text_poke arch/x86/kernel/alternative.c:2660 [inline]
smp_text_poke_batch_finish+0xd36/0x1160 arch/x86/kernel/alternative.c:3049
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:900
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245