INFO: task kworker/u8:9:6723 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9 state:D stack:23912 pid:6723 tgid:6723 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
f2fs_down_write fs/f2fs/f2fs.h:2294 [inline]
f2fs_balance_fs+0x5ab/0x7f0 fs/f2fs/segment.c:464
f2fs_write_inode+0x3fb/0x5f0 fs/f2fs/inode.c:820
write_inode fs/fs-writeback.c:1564 [inline]
__writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1784
writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2086
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2197
wb_check_old_data_flush fs/fs-writeback.c:2301 [inline]
wb_do_writeback fs/fs-writeback.c:2354 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2382
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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 pool_workqueue_/3:
#0: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
3 locks held by kworker/u8:0/12:
#0: ffff88814cbb1948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88814cbb1948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90000117ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90000117ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
3 locks held by kworker/u8:1/13:
#0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90000127ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90000127ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by khungtaskd/31:
#0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by dhcpcd/5529:
#0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978
2 locks held by getty/5622:
#0: ffff88803099b0a0 (&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
4 locks held by kworker/u8:9/6723:
#0: ffff8881432f0948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff8881432f0948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000b70fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000b70fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff8880298c80e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
#3: ffff888055d09478 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2294 [inline]
#3: ffff888055d09478 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x5ab/0x7f0 fs/f2fs/segment.c:464
6 locks held by syz.2.173/6933:
3 locks held by kworker/u8:12/7538:
#0: ffff888034152148 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888034152148 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004e27ba0 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004e27ba0 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work+0x29/0xa50 net/ipv4/udp_tunnel_nic.c:736
2 locks held by syz-executor/9332:
#0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
#1: ffff888077661528 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50
1 lock held by syz.6.575/9552:
2 locks held by syz.7.584/9613:
#0: ffffffff8ea9b2a8 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline]
#0: ffffffff8ea9b2a8 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1786
#1: ffffffff8e342c80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820
2 locks held by syz.9.588/9672:
#0: ffff888055ebbcd8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3b/0x100 net/netfilter/nf_tables_api.c:11499
#1: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6933 Comm: syz.2.173 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:native_apic_msr_eoi+0xf/0x20 arch/x86/include/asm/apic.h:218
Code: f8 e9 55 e1 0f 0a cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa b9 0b 08 00 00 31 c0 31 d2 0f 30 cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc90000007fc8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffc9000533e658 RCX: 000000000000080b
RDX: 0000000000000000 RSI: ffffffff8ba7b4e0 RDI: ffffffff8c03da60
RBP: 0000000000000000 R08: ffffffff8fc35777 R09: 1ffffffff1f86aee
R10: dffffc0000000000 R11: ffffc90000007ff8 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f14aedf16c0(0000) GS:ffff8881259fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564bb02f6d51 CR3: 00000000797f2000 CR4: 00000000003526f0
Call Trace:
apic_eoi arch/x86/include/asm/apic.h:414 [inline]
__sysvec_apic_timer_interrupt+0x45/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline]
RIP: 0010:vprintk_emit+0x49d/0x590 kernel/printk/printk.c:2422
Code: 0f 84 34 ff ff ff e8 62 9a 1f 00 fb eb 44 e8 5a 9a 1f 00 e8 45 e1 de 09 4d 85 f6 74 94 e8 4b 9a 1f 00 fb 48 c7 c7 40 13 33 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 2b 3b
RSP: 0018:ffffc9000533e700 EFLAGS: 00000293
RAX: ffffffff81a0c0d5 RBX: ffffffff81a0bf2e RCX: ffff88807c7c8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e331340
RBP: ffffc9000533e810 R08: ffffffff8fc35777 R09: 1ffffffff1f86aee
R10: dffffc0000000000 R11: fffffbfff1f86aef R12: 0000000000000000
R13: 000000000000006c R14: 0000000000000200 R15: 1ffff92000a67ce4
_printk+0xcf/0x120 kernel/printk/printk.c:2448
bio_check_eod block/blk-core.c:565 [inline]
submit_bio_noacct+0x118a/0x1b80 block/blk-core.c:801
f2fs_submit_page_read+0x116/0x190 fs/f2fs/data.c:1110
f2fs_get_read_data_folio+0x4a4/0x7d0 fs/f2fs/data.c:1268
gc_data_segment fs/f2fs/gc.c:1641 [inline]
do_garbage_collect+0x42f6/0x65d0 fs/f2fs/gc.c:1826
f2fs_gc+0xc8d/0x25a0 fs/f2fs/gc.c:1931
f2fs_balance_fs+0x5f7/0x7f0 fs/f2fs/segment.c:466
f2fs_map_blocks+0x345f/0x4130 fs/f2fs/data.c:1792
f2fs_expand_inode_data+0x5af/0xa60 fs/f2fs/file.c:1923
f2fs_fallocate+0x4f5/0x990 fs/f2fs/file.c:2026
vfs_fallocate+0x669/0x7e0 fs/open.c:342
ioctl_preallocate fs/ioctl.c:289 [inline]
file_ioctl+0x611/0x780 fs/ioctl.c:-1
do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576
__do_sys_ioctl fs/ioctl.c:595 [inline]
__se_sys_ioctl+0x82/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f14adf8eec9
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:00007f14aedf1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f14ae1e5fa0 RCX: 00007f14adf8eec9
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007f14ae011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f14ae1e6038 R14: 00007f14ae1e5fa0 R15: 00007ffd7a5d0be8