INFO: task kworker/u8:9:2833 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:21376 pid:2833 tgid:2833 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x14de/0x5210 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2dc/0x710 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75d/0x1060 fs/fs-writeback.c:1813
writeback_sb_inodes+0x92e/0x1910 fs/fs-writeback.c:2041
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118
wb_writeback+0x459/0xad0 fs/fs-writeback.c:2229
wb_check_old_data_flush fs/fs-writeback.c:2333 [inline]
wb_do_writeback fs/fs-writeback.c:2386 [inline]
wb_workfn+0xaf3/0xf00 fs/fs-writeback.c:2414
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:467
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:
2 locks held by kworker/u8:1/13:
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc90000127c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90000127c40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
1 lock held by khungtaskd/38:
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:4/68:
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc9000153fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000153fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
7 locks held by kworker/u8:5/173:
#0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc90003abfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90003abfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8ef3f800 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670
#3: ffff888032f560d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff888032f560d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff888032f560d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0 net/devlink/core.c:506
#4: ffff888039212300 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff888039212300 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff888039212300 (&devlink->lock_key#9){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0 net/devlink/core.c:506
#5: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1175
#6: ffff88803bebce98 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2781 [inline]
#6: ffff88803bebce98 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x583/0x2360 net/core/dev.c:12356
3 locks held by kworker/u8:6/1046:
#0: ffff888032444138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888032444138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc900047b7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc900047b7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194
4 locks held by kworker/u8:9/2833:
#0: ffff88801f290938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801f290938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc9000cc8fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000cc8fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffff8880392dc0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff888060aad9a8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
2 locks held by getty/5551:
#0: ffff888037b700a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
4 locks held by syz.3.74/6365:
4 locks held by udevd/7365:
1 lock held by syz-executor/7655:
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5027
1 lock held by syz-executor/7708:
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5027
1 lock held by syz-executor/7773:
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
2 locks held by syz-executor/8138:
#0: ffffffff8ef3f800 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577
#1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146
3 locks held by dhcpcd-run-hook/8160:
=============================================
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 02/12/2026
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+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7365 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:arch_stack_walk+0x122/0x150 arch/x86/kernel/stacktrace.c:24
Code: 5a 09 00 48 85 c0 74 24 48 89 df 48 89 c6 4d 89 f3 2e 2e 2e 41 ff d3 84 c0 74 11 4c 89 ff e8 a5 5b 09 00 83 bd 78 ff ff ff 00 <75> cf 65 48 8b 05 14 7a bc 10 48 3b 45 d8 75 12 48 83 c4 68 5b 41
RSP: 0018:ffffc900031ff928 EFLAGS: 00000202
RAX: 000000008fe34001 RBX: ffffc900031ff9e0 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8d5a1617 RDI: ffff88802bd90000
RBP: ffffc900031ff9b0 R08: ffffc900031ffca0 R09: 0000000000000000
R10: ffffc900031ff978 R11: fffff5200063ff31 R12: ffff88802bd90000
R13: 0000000000000000 R14: ffffffff81ae4380 R15: ffffc900031ff928
FS: 00007f5390f56880(0000) GS:ffff888126595000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdfbdaf7dac CR3: 000000003acb0000 CR4: 00000000003526f0
Call Trace:
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2670 [inline]
slab_free mm/slub.c:6082 [inline]
kmem_cache_free+0x185/0x690 mm/slub.c:6212
class_filename_destructor include/linux/fs.h:2539 [inline]
class_filename_uflags_destructor include/linux/fs.h:2542 [inline]
do_utimes_path fs/utimes.c:106 [inline]
do_utimes+0x256/0x2c0 fs/utimes.c:139
__do_sys_utimensat fs/utimes.c:158 [inline]
__se_sys_utimensat fs/utimes.c:142 [inline]
__x64_sys_utimensat+0x15e/0x240 fs/utimes.c:142
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f53910b2a1a
Code: 77 06 c3 0f 1f 44 00 00 48 8b 15 d9 b3 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 41 89 ca b8 18 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 8b 15 a9 b3 0d 00 f7
RSP: 002b:00007ffc062ee098 EFLAGS: 00000246 ORIG_RAX: 0000000000000118
RAX: ffffffffffffffda RBX: 00007ffc062eea70 RCX: 00007f53910b2a1a
RDX: 0000000000000000 RSI: 00007ffc062eea70 RDI: 00000000ffffff9c
RBP: 00007ffc062eea7f R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000246 R12: 00007ffc062ee550
R13: 00007ffc062ee150 R14: 000055e8fcb446d7 R15: 000055e939d644c0