INFO: task syz-executor:5824 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:22008 pid:5824  tgid:5824  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833
 sync_filesystem+0x17a/0x230 fs/sync.c:64
 generic_shutdown_super+0x6f/0x2c0 fs/super.c:621
 kill_block_super+0x44/0x90 fs/super.c:1710
 ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7393
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1431
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50
 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+0x9a/0x120 kernel/entry/common.c:218
 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f958f58fc97
RSP: 002b:00007ffd682f2088 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f958f61089d RCX: 00007f958f58fc97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd682f2140
RBP: 00007ffd682f2140 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd682f31d0
R13: 00007f958f61089d R14: 00000000000eedf9 R15: 00007ffd682f3210
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: 
ffffffff8df3dee0
 (
rcu_read_lock
){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
9 locks held by kworker/u8:7/4581:
2 locks held by getty/5582:
 #0: ffff88814d7f70a0
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/5824:
 #0: ffff888028d820e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888028d820e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888028d820e0 (&type->s_umount_key#32){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffff8880247847d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880247847d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
6 locks held by kworker/u8:12/6149:
 #0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc9000b3a7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000b3a7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: 
ffffffff8f2edd10
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
 #3: 
ffff888058fef0e8
 (&dev->mutex
){....}-{4:4}