INFO: task syz.0.559:8988 blocked for more than 143 seconds.
      Not tainted 6.13.0-rc6-next-20250107-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.559       state:D stack:23120 pid:8988  tgid:8986  ppid:5833   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5371 [inline]
 __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758
 __schedule_loop kernel/sched/core.c:6835 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6850
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6907
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564
 do_writepages+0x35f/0x880 mm/page-writeback.c:2683
 filemap_fdatawrite_wbc mm/filemap.c:389 [inline]
 __filemap_fdatawrite_range mm/filemap.c:422 [inline]
 __filemap_fdatawrite mm/filemap.c:428 [inline]
 filemap_fdatawrite+0x1f3/0x2a0 mm/filemap.c:433
 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219
 __fput+0x3e9/0x9f0 fs/file_table.c:450
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 get_signal+0x15f7/0x1750 kernel/signal.c:2790
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4034985d29
RSP: 002b:00007f403587c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: 0000000000010000 RBX: 00007f4034b75fa0 RCX: 00007f4034985d29
RDX: 0000000000000000 RSI: 000000000000000c RDI: 000000000000000b
RBP: 00007f4034a01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4034b75fa0 R15: 00007ffd4508a398
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/12:
1 lock held by rcu_preempt/17:
 #0: ffff8880b873e958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
1 lock held by khungtaskd/30:
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by getty/5588:
 #0: ffff888031d150a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:10/6037:
2 locks held by kworker/u8:16/7243:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310
 #1: ffffc900044e7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900044e7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310
5 locks held by kworker/u8:19/7253:
1 lock held by syz.0.559/8988:
 #0: ffff88807bb891e0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564
3 locks held by syz.0.559/8992:
 #0: ffff88802e800420 (sb_writers#33){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547
 #1: ffff88807bb88e28 (&sb->s_type->i_mutex_key#40){++++}-{4:4}, at: inode_lock include/linux/fs.h:865 [inline]
 #1: ffff88807bb88e28 (&sb->s_type->i_mutex_key#40){++++}-{4:4}, at: vfs_utimes+0x44d/0x770 fs/utimes.c:65
 #2: ffff88807bb891e0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558
3 locks held by syz.8.754/10161:
 #0: ffffffff8fcaf210 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:512
 #1: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: setup_net+0x602/0x9e0 net/core/net_namespace.c:384
 #2: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline]
 #2: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:996
4 locks held by dhcpcd-run-hook/10173:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc6-next-20250107-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 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:234 [inline]
 watchdog+0xff6/0x1040 kernel/hung_task.c:397
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5823 Comm: syz-executor Not tainted 6.13.0-rc6-next-20250107-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:712 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:715
Code: f0 66 7b 03 eb cd 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 d3 5e 7e e8 1b 77 4d 0a 89 c3 83 f8 08 73 7a
RSP: 0018:ffffc90003dcfbf0 EFLAGS: 00000257
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff819aa134
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901ac9f0
RBP: ffffc90003dcfd58 R08: ffffffff901ac9f7 R09: 1ffffffff203593e
R10: dffffc0000000000 R11: fffffbfff203593f R12: 1ffff920007b9f88
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100238b82b
FS:  000055556c73f500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f318ffc4290 CR3: 000000007b45e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0xe3/0x550 kernel/locking/lockdep.c:5822
 __might_fault+0xc6/0x120 mm/memory.c:6903
 clear_rseq_cs kernel/rseq.c:344 [inline]
 rseq_ip_fixup kernel/rseq.c:378 [inline]
 __rseq_handle_notify_resume+0x634/0x14e0 kernel/rseq.c:416
 rseq_handle_notify_resume include/linux/rseq.h:38 [inline]
 resume_user_mode_work include/linux/resume_user_mode.h:62 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x115/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba4edb85a3
Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 9e 3f 19 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007ffc92ade728 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fba4edb85a3
RDX: 00007ffc92ade740 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 000000001e6ee6e1 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc92adeb90
R13: 0000000000000004 R14: 00007ffc92ade77c R15: 00007ffc92ade810
 </TASK>