INFO: task kworker/u8:4:64 blocked for more than 143 seconds.
      Not tainted 6.11.0-rc4-syzkaller-00008-g6e4436539ae1 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:18648 pid:64    tgid:64    ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105
 write_inode fs/fs-writeback.c:1497 [inline]
 __writeback_single_inode+0x6b9/0x10b0 fs/fs-writeback.c:1716
 writeback_sb_inodes+0x99c/0x1380 fs/fs-writeback.c:1947
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2018
 wb_writeback+0x495/0xd40 fs/fs-writeback.c:2129
 wb_check_old_data_flush fs/fs-writeback.c:2233 [inline]
 wb_do_writeback fs/fs-writeback.c:2286 [inline]
 wb_workfn+0xba1/0x1090 fs/fs-writeback.c:2314
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
1 lock held by ksoftirqd/1/24:
 #0: ffff8880b933e998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560
1 lock held by khungtaskd/30:
 #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626
4 locks held by kworker/0:2/59:
 #0: ffff8880b923e998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560
 #1: ffff8880b9228948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989
 #2: ffff88806c278da0 (&r->consumer_lock#2){+.+.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #2: ffff88806c278da0 (&r->consumer_lock#2){+.+.}-{2:2}, at: ptr_ring_consume_bh include/linux/ptr_ring.h:365 [inline]
 #2: ffff88806c278da0 (&r->consumer_lock#2){+.+.}-{2:2}, at: wg_packet_encrypt_worker+0x12a6/0x1610 drivers/net/wireguard/send.c:293
 #3: ffff8880b933e118 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x759/0xf50
4 locks held by kworker/u8:4/64:
 #0: ffff88801b28a148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88801b28a148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc900015f7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc900015f7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff8880296bc0e0 (&type->s_umount_key#50){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562
 #3: ffff88806de720e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105
2 locks held by kworker/u8:5/1109:
2 locks held by getty/4977:
 #0: ffff88802b0030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by syz-executor/9183:
2 locks held by syz.4.574/10931:
 #0: ffff8880296bc0e0 (&type->s_umount_key#50){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880296bc0e0 (&type->s_umount_key#50){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff8880206b87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline]
 #1: ffff8880206b87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xb20 fs/fs-writeback.c:2790
3 locks held by syz-executor/11350:
 #0: ffff88801e95cd80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff88801e95cd80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2692
 #1: ffff88801e95c078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5145
 #2: ffffffff8fbdda68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1977 [inline]
 #2: ffffffff8fbdda68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592
2 locks held by syz.3.625/11390:
 #0: ffff8880296bc0e0 (&type->s_umount_key#50){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880296bc0e0 (&type->s_umount_key#50){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff8880206b87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline]
 #1: ffff8880206b87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xb20 fs/fs-writeback.c:2790
2 locks held by syz.0.649/11673:
 #0: ffff8880296bc0e0 (&type->s_umount_key#50){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880296bc0e0 (&type->s_umount_key#50){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff8880206b87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline]
 #1: ffff8880206b87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xb20 fs/fs-writeback.c:2790
1 lock held by syz-executor/11765:
 #0: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline]
 #0: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958
2 locks held by dhcpcd/11819:
 #0: ffff88805fe6d608 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline]
 #0: ffff88805fe6d608 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff88805fe6d608 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1421
 #1: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline]
 #1: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958
1 lock held by dhcpcd-run-hook/11831:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc4-syzkaller-00008-g6e4436539ae1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11765 Comm: syz-executor Not tainted 6.11.0-rc4-syzkaller-00008-g6e4436539ae1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:722
Code: e8 b5 68 68 03 eb 80 e8 be 65 34 0a 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 57 41 56 53 65 ff 05 b8 12 8a 7e e8 eb 83 34 0a 89
RSP: 0018:ffffc900044ff4e0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 00007ff57917bd0c RCX: dffffc0000000000
RDX: ffff888018b2da00 RSI: 00007ff57917b000 RDI: ffffffffff600000
RBP: 0000000000000001 R08: ffffffff8100b4fd R09: ffffffff814140bf
R10: 0000000000000003 R11: ffff888018b2da00 R12: ffff888018b2da00
R13: ffffffff817f30a0 R14: dffffc0000000000 R15: 1ffff9200089feb1
FS:  0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1eeb45d5e8 CR3: 0000000068a08000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 kernel_text_address+0x82/0xe0 kernel/extable.c:113
 __kernel_text_address+0xd/0x40 kernel/extable.c:79
 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369
 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfb/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x76/0x430 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd19/0xea0 mm/page_alloc.c:2612
 vfree+0x186/0x2e0 mm/vmalloc.c:3364
 kcov_put kernel/kcov.c:438 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:534
 __fput+0x24a/0x8a0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2f/0x27f0 kernel/exit.c:882
 do_group_exit+0x207/0x2c0 kernel/exit.c:1031
 get_signal+0x1695/0x1730 kernel/signal.c:2917
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff57917bd0c
Code: Unable to access opcode bytes at 0x7ff57917bce2.
RSP: 002b:00007ffe96c4d910 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 0000000000000064 RBX: 00007ff579e44620 RCX: 00007ff57917bd0c
RDX: 0000000000000064 RSI: 00007ff579e44670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe96c4d964 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007ff579e44670 R15: 0000000000000000
 </TASK>