INFO: task syz-executor594:5070 blocked for more than 143 seconds.
      Not tainted 6.6.0-syzkaller-15859-g89cdf9d55601 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor594 state:D stack:25000 pid:5070  tgid:5070  ppid:5067   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5376 [inline]
 __schedule+0x1960/0x4a80 kernel/sched/core.c:6688
 __schedule_loop kernel/sched/core.c:6763 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6778
 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192
 sync_inodes_sb+0x293/0xb20 fs/fs-writeback.c:2758
 sync_filesystem+0x16f/0x220 fs/sync.c:64
 generic_shutdown_super+0x72/0x2c0 fs/super.c:669
 kill_block_super+0x44/0x90 fs/super.c:1667
 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7330
 deactivate_locked_super+0xc1/0x130 fs/super.c:484
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256
 task_work_run+0x24a/0x300 kernel/task_work.c:180
 ptrace_notify+0x2cd/0x380 kernel/signal.c:2399
 ptrace_report_syscall include/linux/ptrace.h:411 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline]
 syscall_exit_work kernel/entry/common.c:251 [inline]
 syscall_exit_to_user_mode_prepare kernel/entry/common.c:278 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x15c/0x280 kernel/entry/common.c:296
 do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f3c4ee8d587
RSP: 002b:00007ffe9ec7cde8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f3c4ee8d587
RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffe9ec7cea0
RBP: 00007ffe9ec7cea0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffe9ec7df10
R13: 00005555567336c0 R14: 431bde82d7b634db R15: 00007ffe9ec7df30
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d92d0a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline]
 #0: ffffffff8d92d0a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
 #0: ffffffff8d92d0a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6613
3 locks held by kworker/0:1H/96:
4 locks held by kworker/u4:7/2436:
 #0: ffff888015272538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
 #0: ffff888015272538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1400 kernel/workqueue.c:2703
 #1: ffffc9000a11fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
 #1: ffffc9000a11fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1400 kernel/workqueue.c:2703
 #2: ffff88801df96b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline]
 #2: ffff88801df96b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1bd/0x3e0 fs/ext4/inode.c:2773
 #3: ffff88807ab3aa88 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x959/0x1cb0 fs/ext4/inode.c:614
2 locks held by getty/4821:
 #0: ffff88814b1cf0a0 (&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+0x6b4/0x1e10 drivers/tty/n_tty.c:2201
2 locks held by syz-executor594/5070:
 #0: ffff88801df940e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88801df940e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88801df940e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:516
 #1: ffff8881407927d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
 #1: ffff8881407927d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xb20 fs/fs-writeback.c:2756

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.0-syzkaller-15859-g89cdf9d55601 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
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+0x198/0x310 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xfa9/0xff0 kernel/hung_task.c:379
 kthread+0x2d3/0x370 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12 Comm: kworker/u4:1 Not tainted 6.6.0-syzkaller-15859-g89cdf9d55601 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:memset_orig+0x36/0xac arch/x86/lib/memset_64.S:68
Code: b8 01 01 01 01 01 01 01 01 48 0f af c1 41 89 f9 41 83 e1 07 75 6c 48 89 d1 48 c1 e9 06 74 35 0f 1f 44 00 00 48 ff c9 48 89 07 <48> 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 48 89 47 28 48 89
RSP: 0018:ffffc90000116fd8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffc900001175e0 RCX: 0000000000000000
RDX: 0000000000000048 RSI: 0000000000000000 RDI: ffffc90000117600
RBP: ffffc900001176d0 R08: ffffc90000117647 R09: 0000000000000000
R10: ffffc90000117600 R11: fffff52000022ec9 R12: 1ffff11002a4c60b
R13: dffffc0000000000 R14: ffff8880b993c340 R15: ffff888015263058
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4c07b44a08 CR3: 000000000d730000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 load_balance+0x18a/0x8b70 kernel/sched/fair.c:11107
 newidle_balance+0x6be/0x1080 kernel/sched/fair.c:12196
 pick_next_task_fair+0x27a/0xdc0 kernel/sched/fair.c:8339
 __pick_next_task kernel/sched/core.c:5997 [inline]
 pick_next_task kernel/sched/core.c:6072 [inline]
 __schedule+0x7ce/0x4a80 kernel/sched/core.c:6652
 __schedule_loop kernel/sched/core.c:6763 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6778
 toggle_allocation_gate+0x16a/0x250 mm/kfence/core.c:832
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x90f/0x1400 kernel/workqueue.c:2703
 worker_thread+0xa5f/0xff0 kernel/workqueue.c:2784
 kthread+0x2d3/0x370 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.677 msecs