INFO: task syz-executor.4:5047 blocked for more than 143 seconds.
      Not tainted 6.4.0-rc6-syzkaller-00242-g1639fae5132b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:20416 pid:5047  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5343 [inline]
 __schedule+0x187b/0x4900 kernel/sched/core.c:6669
 schedule+0xc3/0x180 kernel/sched/core.c:6745
 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192
 sync_inodes_sb+0x297/0xab0 fs/fs-writeback.c:2730
 sync_filesystem+0x16f/0x220 fs/sync.c:64
 generic_shutdown_super+0x6f/0x340 fs/super.c:473
 kill_block_super+0x84/0xf0 fs/super.c:1407
 deactivate_locked_super+0xa4/0x110 fs/super.c:331
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1177
 task_work_run+0x24a/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd0e188d7f7
RSP: 002b:00007ffdd3e1f2c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fd0e188d7f7
RDX: 00007ffdd3e1f399 RSI: 000000000000000a RDI: 00007ffdd3e1f390
RBP: 00007ffdd3e1f390 R08: 00000000ffffffff R09: 00007ffdd3e1f160
R10: 0000555555f62873 R11: 0000000000000246 R12: 00007fd0e18d643b
R13: 00007ffdd3e20450 R14: 0000555555f62810 R15: 00007ffdd3e20490
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/13:
 #0: ffffffff8cf276f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518
1 lock held by rcu_tasks_trace/14:
 #0: ffffffff8cf27ab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518
1 lock held by khungtaskd/28:
 #0: ffffffff8cf27520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:3/46:
2 locks held by getty/4749:
 #0: ffff888028e9a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176
2 locks held by syz-executor.4/5047:
 #0: ffff88801b6ae0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361
 #1: ffff888140bfc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff888140bfc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x278/0xab0 fs/fs-writeback.c:2728

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc6-syzkaller-00242-g1639fae5132b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x187/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xec2/0xf00 kernel/hung_task.c:379
 kthread+0x2b8/0x350 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 930 Comm: kworker/u4:5 Not tainted 6.4.0-rc6-syzkaller-00242-g1639fae5132b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: bat_events batadv_purge_orig
RIP: 0010:__local_bh_disable_ip+0xc/0x220 kernel/softirq.c:318
Code: 1e fa 89 f6 e9 25 85 41 00 0f 1f 44 00 00 f3 0f 1e fa e9 a7 88 41 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56 <41> 55 41 54 53 48 83 e4 e0 48 81 ec a0 00 00 00 41 89 f7 48 89 7c
RSP: 0018:ffffc90003d1faa8 EFLAGS: 00000286
RAX: 1ffff110286609a1 RBX: ffffffff8a80bb48 RCX: ffff888143304d00
RDX: ffff888143304d08 RSI: 0000000000000201 RDI: ffffffff8a80bb48
RBP: ffffc90003d1fab8 R08: dffffc0000000000 R09: fffffbfff2065668
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88801f95bc28 R14: ffff888037db09c0 R15: ffff88801f95bc18
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c000d9c000 CR3: 000000000cd30000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:125 [inline]
 _raw_spin_lock_bh+0x1c/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:355 [inline]
 batadv_purge_orig_ref+0x1b8/0x15a0 net/batman-adv/originator.c:1243
 batadv_purge_orig+0x19/0x60 net/batman-adv/originator.c:1272
 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405
 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552
 kthread+0x2b8/0x350 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>