------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.1.128-syzkaller #0 Not tainted
------------------------------------------------------
kworker/1:5/4297 is trying to acquire lock:
ffffffff8d31f580 (console_owner){..-.}-{0:0}, at: console_lock_spinning_enable kernel/printk/printk.c:1818 [inline]
ffffffff8d31f580 (console_owner){..-.}-{0:0}, at: console_emit_next_record+0xa9c/0x1000 kernel/printk/printk.c:2774

but task is already holding lock:
ffff8880b8f3a218 (&pool->lock){-.-.}-{2:2}, at: start_flush_work kernel/workqueue.c:3022 [inline]
ffff8880b8f3a218 (&pool->lock){-.-.}-{2:2}, at: __flush_work+0x1e6/0xad0 kernel/workqueue.c:3075

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&pool->lock){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
       __queue_work+0x58c/0xf90
       queue_work_on+0x14b/0x250 kernel/workqueue.c:1548
       queue_work include/linux/workqueue.h:512 [inline]
       schedule_work include/linux/workqueue.h:573 [inline]
       p9_pollwake+0x142/0x160 net/9p/trans_fd.c:540
       __wake_up_common+0x2a0/0x4e0 kernel/sched/wait.c:107
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x11a/0x1c0 kernel/sched/wait.c:160
       tty_write_unlock drivers/tty/tty_io.c:939 [inline]
       do_tty_write drivers/tty/tty_io.c:1043 [inline]
       file_tty_write+0x7ab/0x890 drivers/tty/tty_io.c:1089
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xfd/0x1c0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:71
       serial8250_tx_chars+0x60d/0x800 drivers/tty/serial/8250/8250_port.c:1854
       serial8250_handle_irq+0x4ff/0x6a0 drivers/tty/serial/8250/8250_port.c:1961
       serial8250_default_handle_irq+0xc8/0x1e0 drivers/tty/serial/8250/8250_port.c:1981
       serial8250_interrupt+0xa1/0x1e0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x2a8/0xb20 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x85/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x245/0xbf0 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:231 [inline]
       __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250
       common_interrupt+0xae/0xd0 arch/x86/kernel/irq.c:240
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_write+0x6af/0x930 drivers/tty/serial/serial_core.c:602
       process_output_block drivers/tty/n_tty.c:586 [inline]
       n_tty_write+0xd7f/0x1260 drivers/tty/n_tty.c:2377
       do_tty_write drivers/tty/tty_io.c:1018 [inline]
       file_tty_write+0x504/0x890 drivers/tty/tty_io.c:1089
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&port_lock_key){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       serial8250_console_write+0x19d/0x1750 drivers/tty/serial/8250/8250_port.c:3404
       call_console_driver kernel/printk/printk.c:1977 [inline]
       console_emit_next_record+0xbb4/0x1000 kernel/printk/printk.c:2777
       console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906
       vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303
       _printk+0xd1/0x111 kernel/printk/printk.c:2328
       register_console+0x6b9/0x9a0 kernel/printk/printk.c:3269
       univ8250_console_init+0x41/0x43 drivers/tty/serial/8250/8250_core.c:687
       console_init+0x1d6/0x7f3 kernel/printk/printk.c:3359
       start_kernel+0x30b/0x53f init/main.c:1076
       secondary_startup_64_no_verify+0xcf/0xdb

-> #0 (console_owner){..-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       console_lock_spinning_enable kernel/printk/printk.c:1818 [inline]
       console_emit_next_record+0xabd/0x1000 kernel/printk/printk.c:2774
       console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906
       vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303
       _printk+0xd1/0x111 kernel/printk/printk.c:2328
       __warn_printk+0x233/0x350 kernel/panic.c:723
       check_flush_dependency+0x2a6/0x340 kernel/workqueue.c:2631
       start_flush_work kernel/workqueue.c:3035 [inline]
       __flush_work+0x2c7/0xad0 kernel/workqueue.c:3075
       flush_work kernel/workqueue.c:3097 [inline]
       flush_delayed_work+0x14b/0x1a0 kernel/workqueue.c:3221
       hfs_file_fsync+0xe9/0x140 fs/hfs/inode.c:686
       generic_write_sync include/linux/fs.h:2962 [inline]
       dio_complete+0x66e/0x7b0 fs/direct-io.c:309
       process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
       worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
       kthread+0x28d/0x320 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

other info that might help us debug this:

Chain exists of:
  console_owner --> &tty->write_wait --> &pool->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pool->lock);
                               lock(&tty->write_wait);
                               lock(&pool->lock);
  lock(console_owner);

 *** DEADLOCK ***

6 locks held by kworker/1:5/4297:
 #0: ffff888058533538 ((wq_completion)dio/loop7){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90004407d20 ((work_completion)(&dio->complete_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff8880545c1628 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff8880545c1628 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: hfs_file_fsync+0x94/0x140 fs/hfs/inode.c:679
 #3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: __flush_work+0xe5/0xad0 kernel/workqueue.c:3072
 #4: ffff8880b8f3a218 (&pool->lock){-.-.}-{2:2}, at: start_flush_work kernel/workqueue.c:3022 [inline]
 #4: ffff8880b8f3a218 (&pool->lock){-.-.}-{2:2}, at: __flush_work+0x1e6/0xad0 kernel/workqueue.c:3075
 #5: ffffffff8d2072e0 (console_lock){+.+.}-{0:0}, at: _printk+0xd1/0x111 kernel/printk/printk.c:2328

stack backtrace:
CPU: 1 PID: 4297 Comm: kworker/1:5 Not tainted 6.1.128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: dio/loop7 dio_aio_complete_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 console_lock_spinning_enable kernel/printk/printk.c:1818 [inline]
 console_emit_next_record+0xabd/0x1000 kernel/printk/printk.c:2774
 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906
 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303
 _printk+0xd1/0x111 kernel/printk/printk.c:2328
 __warn_printk+0x233/0x350 kernel/panic.c:723
 check_flush_dependency+0x2a6/0x340 kernel/workqueue.c:2631
 start_flush_work kernel/workqueue.c:3035 [inline]
 __flush_work+0x2c7/0xad0 kernel/workqueue.c:3075
 flush_work kernel/workqueue.c:3097 [inline]
 flush_delayed_work+0x14b/0x1a0 kernel/workqueue.c:3221
 hfs_file_fsync+0xe9/0x140 fs/hfs/inode.c:686
 generic_write_sync include/linux/fs.h:2962 [inline]
 dio_complete+0x66e/0x7b0 fs/direct-io.c:309
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
workqueue: WQ_MEM_RECLAIM dio/loop7:dio_aio_complete_work is flushing !WQ_MEM_RECLAIM events_long:flush_mdb
WARNING: CPU: 1 PID: 4297 at kernel/workqueue.c:2635 check_flush_dependency+0x2a6/0x340 kernel/workqueue.c:2631
Modules linked in:
CPU: 1 PID: 4297 Comm: kworker/1:5 Not tainted 6.1.128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: dio/loop7 dio_aio_complete_work
RIP: 0010:check_flush_dependency+0x2a6/0x340 kernel/workqueue.c:2631
Code: 08 4c 89 e7 e8 8b 52 88 00 49 8b 14 24 49 81 c7 60 01 00 00 48 c7 c7 80 43 0b 8b 4c 89 ee 4c 89 f9 4c 8b 04 24 e8 9a d8 f8 ff <0f> 0b eb 9f 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c b1 fd ff ff 48 89
RSP: 0000:ffffc90004407900 EFLAGS: 00010046
RAX: e327eebfeffc2000 RBX: ffff8880585335c0 RCX: ffff888027a6d940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000008 R08: ffffffff8152b84e R09: ffffed10171e4f1c
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888028ad6918
R13: ffff888058533560 R14: dffffc0000000000 R15: ffff888017c71160
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f312ff8 CR3: 0000000054f53000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 start_flush_work kernel/workqueue.c:3035 [inline]
 __flush_work+0x2c7/0xad0 kernel/workqueue.c:3075
 flush_work kernel/workqueue.c:3097 [inline]
 flush_delayed_work+0x14b/0x1a0 kernel/workqueue.c:3221
 hfs_file_fsync+0xe9/0x140 fs/hfs/inode.c:686
 generic_write_sync include/linux/fs.h:2962 [inline]
 dio_complete+0x66e/0x7b0 fs/direct-io.c:309
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>