INFO: task kworker/u8:0:12 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:19584 pid:12    tgid:12    ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 __mutex_lock_common kernel/locking/mutex.c:678 [inline]
 __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
 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+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/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
4 locks held by kworker/u8:0/12:
 #0: ffff8880202fc148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff8880202fc148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90000117c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000117c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
 #3: ffff888054989438 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
1 lock held by khungtaskd/31:
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/1:2/975:
 #0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc9000386fc60 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000386fc60 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
3 locks held by kworker/u8:5/1032:
 #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc900039cfc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900039cfc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
5 locks held by kworker/u8:7/1152:
 #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90003b5fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90003b5fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffffffff8f2dbdd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
 #3: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x611/0xbd0 net/core/net_namespace.c:644
 #4: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #4: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
1 lock held by dhcpcd/5483:
 #0: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1121
2 locks held by getty/5577:
 #0: ffff8880351420a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by syz.3.305/9121:
2 locks held by syz.8.442/10753:
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.8.442/10754:
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.8.442/10755:
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.8.442/10756:
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.8.442/10759:
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.5.450/10789:
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.7.499/11554:
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888059ed00e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880249a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz-executor/11824:
 #0: ffffffff8ea822e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ea822e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8ea822e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064
2 locks held by syz-executor/11831:
 #0: ffffffff8f7e43b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8f7e43b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8f7e43b0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 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+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11935 Comm: syz.4.538 Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:79
Code: 90 90 f3 0f 1e fa 65 8b 05 75 37 ac 10 85 c0 74 14 48 8b 3c 24 e8 c8 fe ff ff 65 c7 05 5d 37 ac 10 00 00 00 00 e8 58 b8 d6 ff <48> 8b 3c 24 e9 0f 19 88 09 66 66 66 66 66 66 2e 0f 1f 84 00 00 00
RSP: 0000:ffffc9000446fcf8 EFLAGS: 00000082
RAX: 36bbfebf9dd23000 RBX: 1ffff9200088dfa4 RCX: 36bbfebf9dd23000
RDX: 0000000000000007 RSI: ffffffff8d924c59 RDI: ffffffff8bc12300
RBP: ffffc9000446fdd0 R08: ffffffff8f7e0b77 R09: 1ffffffff1efc16e
R10: dffffc0000000000 R11: fffffbfff1efc16f R12: 0000000000000200
R13: dffffc0000000000 R14: 0000000000000017 R15: ffff888028668000
FS:  00007f023525f6c0(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f022a067000 CR3: 000000004614a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 count_memcg_events include/linux/memcontrol.h:966 [inline]
 count_memcg_events_mm include/linux/memcontrol.h:989 [inline]
 count_memcg_event_mm+0x209/0x3b0 include/linux/memcontrol.h:996
 mm_account_fault mm/memory.c:6174 [inline]
 handle_mm_fault+0x43e/0x7f0 mm/memory.c:6335
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1337
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f0234250d66
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f023525e4a0 EFLAGS: 00010206
RAX: 0000000000467001 RBX: 00007f023525e540 RCX: 000000000000008b
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f023525e5e0
RBP: 0000000000000102 R08: 00007f0229c00000 R09: 0000000000467000
R10: 0000000000000000 R11: 00007f023525e550 R12: 0000000000000001
R13: 00007f023442bfc0 R14: 0000000000000000 R15: 00007f023525e5e0
 </TASK>