INFO: task kworker/u8:9:1182 blocked in I/O wait 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:20640 pid:1182 tgid:1182 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:7)
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
io_schedule+0x80/0xe0 kernel/sched/core.c:8154
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x281/0xbe0 fs/jfs/jfs_txnmgr.c:376
jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1607 [inline]
__writeback_single_inode+0x6af/0xf90 fs/fs-writeback.c:1850
writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079
wb_writeback+0x41c/0xad0 fs/fs-writeback.c:2264
wb_do_writeback fs/fs-writeback.c:2432 [inline]
wb_workfn+0x437/0x10f0 fs/fs-writeback.c:2477
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz-executor:8940 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:22296 pid:8940 tgid:8940 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
wb_wait_for_completion+0x3b2/0x700 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x246/0x2e0 fs/fs-writeback.c:2933
sync_filesystem+0xa2/0x250 fs/sync.c:54
generic_shutdown_super+0x77/0x2d0 fs/super.c:626
kill_block_super+0x44/0x90 fs/super.c:1671
deactivate_locked_super+0xbc/0x130 fs/super.c:477
cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b5a52f0d7
RSP: 002b:00007fff07f30578 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f4b5a5c330a RCX: 00007f4b5a52f0d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff07f30630
RBP: 00007fff07f30630 R08: 00007fff07f31630 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff07f316c0
R13: 00007f4b5a5c330a R14: 00000000000988da R15: 00007fff07f31700
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/43:
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc90000b47c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc90000b47c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
15 locks held by kworker/u8:4/66:
2 locks held by kworker/u8:9/1182:
#0: ffff88801f2c7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801f2c7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc900065a7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc900065a7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
2 locks held by getty/5350:
#0: ffff888036dde0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/8940:
#0: ffff888034cdc0d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888034cdc0d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888034cdc0d0 (&type->s_umount_key#56){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509
3 locks held by kworker/u8:7/11176:
#0: ffff888032c0b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff888032c0b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000543fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000543fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4229
1 lock held by syz-executor/11474:
#0: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158
1 lock held by syz-executor/11501:
#0: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158
7 locks held by syz-executor/11744:
#0: ffff888035d42500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#0: ffff888035d42500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#1: ffff88806552bc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336
#2: ffff88802997aa58 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88802997aa58 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337
#3: ffffffff8ee26d18 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184
#4: ffff888034027160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#4: ffff888034027160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
#5: ffff8880227f4310 (&devlink->lock_key#36){+.+.}-{4:4}, at: nsim_drv_probe+0xfc/0xc00 drivers/net/netdevsim/dev.c:1658
#6: ffffffff8f5b1df8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x8b/0x290 net/ipv4/nexthop.c:4017
4 locks held by syz-executor/11834:
#0: ffff888035d42500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#0: ffff888035d42500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#1: ffff8880618ad878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336
#2: ffff88802997a968 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88802997a968 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337
#3: ffffffff8ee26d18 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234
1 lock held by syz.8.554/11970:
2 locks held by dhcpcd-run-hook/11971:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 66 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: netns cleanup_net
RIP: 0010:usage_skip kernel/locking/lockdep.c:2253 [inline]
RIP: 0010:__bfs kernel/locking/lockdep.c:1800 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline]
RIP: 0010:__lock_acquire+0x17f8/0x2ce0 kernel/locking/lockdep.c:5237
Code: 89 ca 80 e2 fa 80 78 2b 00 0f b6 c2 0f 44 c1 84 c0 0f 84 42 ff ff ff a8 0c 41 0f 94 47 2b 4d 8b 6f 10 41 0f b6 85 c6 00 00 00 <85> c0 74 5e 83 f8 01 0f 85 22 ff ff ff 83 3d b4 c2 07 18 00 0f 85
RSP: 0018:ffffc9000151e9b8 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 00000000000003cd RCX: 0000000000000008
RDX: 0000000000000008 RSI: ffff8880202f0e88 RDI: 00000000000003cd
RBP: c9c588ec95a90ef5 R08: ffffc9000151e980 R09: 0000000000000020
R10: 0000000000000000 R11: ffffffff81a1c580 R12: 00000000000006ac
R13: ffffffff93475c68 R14: ffff8880202f0000 R15: ffffffff9629d1b8
FS: 0000000000000000(0000) GS:ffff888125c41000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0028aa9286 CR3: 000000004f2c4000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
debug_object_assert_init+0xa1/0x310 lib/debugobjects.c:1070
debug_hrtimer_assert_init kernel/time/hrtimer.c:495 [inline]
hrtimer_start_range_ns+0x3d/0x3f0 kernel/time/hrtimer.c:1499
enqueue_task+0x75/0x410 kernel/sched/core.c:2184
sched_change_end+0x213/0x600 kernel/sched/core.c:11255
migrate_disable_switch kernel/sched/core.c:2465 [inline]
__schedule+0x1879/0x5500 kernel/sched/core.c:7089
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 61 5c a2 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 2b 97 fc 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 d0 25 a6 09 cc 48 8d 3d 58 9b 11
RSP: 0018:ffffc9000151f040 EFLAGS: 00000282
RAX: 09751981e5d0ee00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 0000000000030000 RSI: ffffffff8daf5218 RDI: ffffffff8bca7780
RBP: ffffffff89f57c37 R08: ffffc9000151ee60 R09: 0000000000000020
R10: 0000000000000000 R11: ffffffff81a1c580 R12: 0000000000000000
R13: ffff88803bbc4c70 R14: 0000000000000001 R15: 0000000000000246
rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56
spin_lock_bh include/linux/spinlock_rt.h:90 [inline]
fib6_gc_all net/ipv6/ip6_fib.c:2416 [inline]
fib6_run_gc+0x2f7/0x920 net/ipv6/ip6_fib.c:2442
ndisc_netdev_event+0xd4/0x4d0 net/ipv6/ndisc.c:1894
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
call_netdevice_notifiers net/core/dev.c:2302 [inline]
netif_close_many+0x2ab/0x410 net/core/dev.c:1806
netif_close_many_and_unlock net/core/dev.c:12340 [inline]
unregister_netdevice_many_notify+0x843/0x2110 net/core/dev.c:12410
unregister_netdevice_many net/core/dev.c:12507 [inline]
unregister_netdevice_queue+0x2f5/0x340 net/core/dev.c:12319
unregister_netdevice include/linux/netdevice.h:3472 [inline]
nsim_destroy+0x275/0x800 drivers/net/netdevsim/netdev.c:1196
__nsim_dev_port_del+0x14e/0x200 drivers/net/netdevsim/dev.c:1547
nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1561 [inline]
nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1785
nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:1038
devlink_reload+0x1c5/0x890 net/devlink/dev.c:462
devlink_pernet_pre_exit+0x1ff/0x420 net/devlink/core.c:560
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x17d/0x8d0 net/core/net_namespace.c:234
cleanup_net+0x575/0x810 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245