INFO: task kworker/u8:6:1098 blocked for more than 143 seconds.
Not tainted 6.15.0-syzkaller-09161-g0f70f5b08a47 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6 state:D stack:22664 pid:1098 tgid:1098 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
context_switch kernel/sched/core.c:5392 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781
__schedule_loop kernel/sched/core.c:6859 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6874
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6931
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
f2fs_down_write fs/f2fs/f2fs.h:2229 [inline]
f2fs_balance_fs+0x558/0x750 fs/f2fs/segment.c:463
f2fs_write_inode+0x3fb/0x5f0 fs/f2fs/inode.c:819
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8e13ccc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13ccc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13ccc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:2/36:
#0: ffff8880b863b858 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
#1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
4 locks held by kworker/u8:6/1098:
#0: ffff8880206c8948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8880206c8948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90003b1fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003b1fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffff888028da40e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88804cfa1410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2229 [inline]
#3: ffff88804cfa1410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x558/0x750 fs/f2fs/segment.c:463
2 locks held by getty/5579:
#0: ffff888030d7d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/7719:
7 locks held by syz.3.227/8179:
1 lock held by syz.2.492/10937:
#0: ffffffff8e1427f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#0: ffffffff8e1427f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
2 locks held by udevadm/10975:
1 lock held by udevadm/10985:
1 lock held by cmp/10988:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-09161-g0f70f5b08a47 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 8179 Comm: syz.3.227 Not tainted 6.15.0-syzkaller-09161-g0f70f5b08a47 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:preempt_count_sub+0x4/0x170 kernel/sched/core.c:5889
Code: 9f 8f e8 4f 73 90 00 e9 5c ff ff ff 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 f3 0f 1e fa <55> 53 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 60 c3 a3 99 48 c1 e8
RSP: 0018:ffffc90003dfe708 EFLAGS: 00000093
RAX: 00000000d5c63531 RBX: 0000000000000899 RCX: 0000000000000001
RDX: 00000000000000f6 RSI: ffffffff8be19260 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffff888024bd8237 R09: 1ffff1100497b046
R10: dffffc0000000000 R11: ffffffff8b5b52e0 R12: 1ffffffff33b03ae
R13: 00000000ffffffff R14: 000000f6d5c632af R15: 0000000000000282
FS: 00007f2c627d16c0(0000) GS:ffff888125d99000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1147598000 CR3: 0000000065042000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
delay_tsc+0x4e/0xc0 arch/x86/lib/delay.c:77
udelay include/asm-generic/delay.h:62 [inline]
wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:2104
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
_printk+0xcf/0x120 kernel/printk/printk.c:2475
bio_check_eod block/blk-core.c:563 [inline]
submit_bio_noacct+0x108b/0x1a70 block/blk-core.c:796
f2fs_submit_page_read+0x116/0x190 fs/f2fs/data.c:1113
f2fs_get_read_data_folio+0x4a4/0x7d0 fs/f2fs/data.c:1271
gc_data_segment fs/f2fs/gc.c:1638 [inline]
do_garbage_collect+0x3866/0x64b0 fs/f2fs/gc.c:1823
f2fs_gc+0xc69/0x2540 fs/f2fs/gc.c:1927
f2fs_balance_fs+0x5a3/0x750 fs/f2fs/segment.c:465
f2fs_map_blocks+0x3c19/0x4510 fs/f2fs/data.c:1791
f2fs_expand_inode_data+0x653/0xaf0 fs/f2fs/file.c:1875
f2fs_fallocate+0x4f5/0x990 fs/f2fs/file.c:1978
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c6198e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2c627d1038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f2c61bb6160 RCX: 00007f2c6198e969
RDX: 0000000000000800 RSI: 0000000000000001 RDI: 0000000000000005
RBP: 00007f2c61a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f2c61bb6160 R15: 00007ffcbdfd24c8