INFO: task kworker/u8:9:6744 blocked for more than 143 seconds.
Not tainted 6.16.0-rc2-next-20250618-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9 state:D stack:21152 pid:6744 tgid:6744 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:5)
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
__schedule_loop kernel/sched/core.c:6774 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6789
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6846
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:132
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6c7/0x1010 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:3239 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 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:
5 locks held by kworker/0:0/9:
#0: ffff888140ebbd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff888140ebbd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc900000e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc900000e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffff88814337b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#2: ffff88814337b198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5863
#3: ffff88814337e510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline]
#3: ffff88814337e510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5432 [inline]
#3: ffff88814337e510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
#3: ffff88814337e510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline]
#3: ffff88814337e510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21a3/0x4a00 drivers/usb/core/hub.c:5917
#4: ffff888144733668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5433 [inline]
#4: ffff888144733668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
#4: ffff888144733668 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline]
#4: ffff888144733668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21cb/0x4a00 drivers/usb/core/hub.c:5917
1 lock held by khungtaskd/31:
#0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:4/59:
#0: ffff8880b8639f58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:614
#1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39a/0x6d0 kernel/sched/psi.c:991
6 locks held by kworker/u8:6/1316:
#0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc9000447fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc9000447fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffffffff8f50abd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
#3: ffff88802abc60e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#3: ffff88802abc60e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff88802abc60e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506
#4: ffff888076418250 (&devlink->lock_key#14){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff888076418250 (&devlink->lock_key#14){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff888076418250 (&devlink->lock_key#14){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506
#5: ffffffff8e144840 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3792
2 locks held by getty/5592:
#0: ffff88814d26e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by kworker/u8:9/6744:
#0: ffff88801e286148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801e286148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc90003d8fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc90003d8fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffff88807dff20e0 (&type->s_umount_key#85){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff8880525f01c8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
2 locks held by kworker/u8:11/10202:
4 locks held by syz.5.2581/16936:
1 lock held by syz.1.2609/17252:
2 locks held by syz-executor/17291:
#0: ffffffff8f5177c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
#0: ffffffff8f5177c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
#1: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:967
2 locks held by syz-executor/17453:
#0: ffffffff8f50abd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570
#1: ffffffff8f5177c8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160
2 locks held by syz-executor/17473:
#0: ffffffff8f50abd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570
#1: ffffffff8f5177c8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210 net/ipv4/nexthop.c:3929
2 locks held by syz-executor/17497:
#0: ffffffff8f50abd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570
#1: ffffffff8f5177c8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210 net/ipv4/nexthop.c:3929
4 locks held by syz.9.2647/17522:
#0: ffff888024048dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff888024048dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715
#1: ffff8880240480b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5238
#2: ffffffff8f67e568 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2068 [inline]
#2: ffffffff8f67e568 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2560
#3: ffff888054ae5338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762
1 lock held by dhcpcd-run-hook/17541:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-next-20250618-syzkaller #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:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 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: 16936 Comm: syz.5.2581 Not tainted 6.16.0-rc2-next-20250618-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d f4 dc fa 0b 48 89 de 5b e9 13 63 59 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 30 9e 92 65 8b 15 d8 d8 dd 10 81 e2 00 01 ff 00
RSP: 0018:ffffc9000e1e76a0 EFLAGS: 00000246
RAX: ffffffff833ff626 RBX: 0000000000000004 RCX: 0000000000080000
RDX: ffffc90004751000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffff888057591000 R08: 0000000200000000 R09: 0000000000000000
R10: 00300065006c0069 R11: 006605ff00000020 R12: dffffc0000000000
R13: 1ffff1100aeb2200 R14: 0000000000000000 R15: 1ffff1100aeb2202
FS: 00007f32efdf66c0(0000) GS:ffff888125d3d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560fefa86138 CR3: 000000002c5ea000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 000000000000003c DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
dtSplitRoot+0x7a6/0x16c0 fs/jfs/jfs_dtree.c:1981
dtSplitUp fs/jfs/jfs_dtree.c:993 [inline]
dtInsert+0xef8/0x5f40 fs/jfs/jfs_dtree.c:871
jfs_symlink+0x715/0xe60 fs/jfs/namei.c:1020
vfs_symlink+0x143/0x2f0 fs/namei.c:4730
do_symlinkat+0x1b1/0x3f0 fs/namei.c:4756
__do_sys_symlink fs/namei.c:4777 [inline]
__se_sys_symlink fs/namei.c:4775 [inline]
__x64_sys_symlink+0x7a/0x90 fs/namei.c:4775
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: 0033:0x7f32f1f8e929
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:00007f32efdf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f32f21b5fa0 RCX: 00007f32f1f8e929
RDX: 0000000000000000 RSI: 0000200000000e40 RDI: 0000200000001640
RBP: 00007f32f2010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f32f21b5fa0 R15: 00007ffe1ea05ee8