------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc4-syzkaller #0 Not tainted
------------------------------------------------------
kworker/0:2/775 is trying to acquire lock:
ffffffff8dd25640 (console_owner){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:334 [inline]
ffffffff8dd25640 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
ffffffff8dd25640 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline]
ffffffff8dd25640 (console_owner){....}-{0:0}, at: console_flush_all+0x152/0xfc0 kernel/printk/printk.c:2986

but task is already holding lock:
ffff8880b943df18 (&pool->lock){-.-.}-{2:2}, at: start_flush_work kernel/workqueue.c:4129 [inline]
ffff8880b943df18 (&pool->lock){-.-.}-{2:2}, at: __flush_work+0x1a8/0xd00 kernel/workqueue.c:4181

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&pool->lock){-.-.}-{2:2}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       __queue_work+0x6e5/0xec0
       queue_work_on+0x1a7/0x2e0 kernel/workqueue.c:2410
       queue_work include/linux/workqueue.h:621 [inline]
       rpm_suspend+0xe70/0x1730 drivers/base/power/runtime.c:662
       __pm_runtime_idle+0x131/0x1a0 drivers/base/power/runtime.c:1104
       pm_runtime_put include/linux/pm_runtime.h:448 [inline]
       __device_attach+0x3e5/0x520 drivers/base/dd.c:1046
       bus_probe_device+0x189/0x260 drivers/base/bus.c:532
       device_add+0x924/0xd10 drivers/base/core.c:3679
       serial_base_port_add+0x2b6/0x3f0 drivers/tty/serial/serial_base_bus.c:179
       serial_core_port_device_add drivers/tty/serial/serial_core.c:3380 [inline]
       serial_core_register_port+0x374/0x2360 drivers/tty/serial/serial_core.c:3421
       serial8250_register_8250_port+0x1433/0x1cd0 drivers/tty/serial/8250/8250_core.c:1140
       serial_pnp_probe+0x4f9/0x9d0 drivers/tty/serial/8250/8250_pnp.c:490
       pnp_device_probe+0x2ba/0x460 drivers/pnp/driver.c:111
       really_probe+0x2b8/0xad0 drivers/base/dd.c:656
       __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:798
       driver_probe_device+0x50/0x430 drivers/base/dd.c:828
       __driver_attach+0x45f/0x710 drivers/base/dd.c:1214
       bus_for_each_dev+0x239/0x2b0 drivers/base/bus.c:368
       bus_add_driver+0x346/0x670 drivers/base/bus.c:673
       driver_register+0x23a/0x320 drivers/base/driver.c:246
       serial8250_init+0x9e/0x170 drivers/tty/serial/8250/8250_core.c:1241
       do_one_initcall+0x248/0x860 init/main.c:1267
       do_initcall_level+0x157/0x210 init/main.c:1329
       do_initcalls+0x3f/0x80 init/main.c:1345
       kernel_init_freeable+0x435/0x5d0 init/main.c:1578
       kernel_init+0x1d/0x2b0 init/main.c:1467
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #2 (&dev->power.lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       __pm_runtime_resume+0x112/0x180 drivers/base/power/runtime.c:1171
       pm_runtime_get include/linux/pm_runtime.h:396 [inline]
       __uart_start+0x17c/0x450 drivers/tty/serial/serial_core.c:148
       uart_write+0x152/0x380 drivers/tty/serial/serial_core.c:633
       process_output_block drivers/tty/n_tty.c:574 [inline]
       n_tty_write+0xd6a/0x1230 drivers/tty/n_tty.c:2389
       iterate_tty_write drivers/tty/tty_io.c:1021 [inline]
       file_tty_write+0x54f/0x9b0 drivers/tty/tty_io.c:1096
       new_sync_write fs/read_write.c:497 [inline]
       vfs_write+0xa72/0xc90 fs/read_write.c:590
       ksys_write+0x1a0/0x2c0 fs/read_write.c:643
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0x82/0x160 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:618 [inline]
       serial8250_console_write+0x1a8/0x1770 drivers/tty/serial/8250/8250_port.c:3352
       console_emit_next_record kernel/printk/printk.c:2928 [inline]
       console_flush_all+0x867/0xfc0 kernel/printk/printk.c:2994
       console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3063
       vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2345
       _printk+0xd5/0x120 kernel/printk/printk.c:2370
       register_console+0x720/0xcd0 kernel/printk/printk.c:3596
       univ8250_console_init+0x49/0x50 drivers/tty/serial/8250/8250_core.c:719
       console_init+0x1b8/0x6e0 kernel/printk/printk.c:3742
       start_kernel+0x2d3/0x500 init/main.c:1038
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x3a63/0x8010 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x540 kernel/locking/lockdep.c:5754
       console_lock_spinning_enable kernel/printk/printk.c:1870 [inline]
       console_emit_next_record kernel/printk/printk.c:2922 [inline]
       console_flush_all+0x810/0xfc0 kernel/printk/printk.c:2994
       console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3063
       vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2345
       _printk+0xd5/0x120 kernel/printk/printk.c:2370
       __warn_printk+0x237/0x360 kernel/panic.c:737
       check_flush_dependency+0x2b0/0x350 kernel/workqueue.c:3706
       start_flush_work kernel/workqueue.c:4143 [inline]
       __flush_work+0x286/0xd00 kernel/workqueue.c:4181
       flush_work kernel/workqueue.c:4232 [inline]
       flush_delayed_work+0x169/0x1c0 kernel/workqueue.c:4254
       hfs_file_fsync+0xed/0x140 fs/hfs/inode.c:678
       generic_write_sync include/linux/fs.h:2794 [inline]
       dio_complete+0x567/0x6c0 fs/direct-io.c:314
       process_one_work kernel/workqueue.c:3231 [inline]
       process_scheduled_works+0xa2c/0x1810 kernel/workqueue.c:3312
       worker_thread+0xa60/0xff0 kernel/workqueue.c:3393
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

Chain exists of:
  console_owner --> &dev->power.lock --> &pool->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pool->lock);
                               lock(&dev->power.lock);
                               lock(&pool->lock);
  lock(console_owner);

 *** DEADLOCK ***

7 locks held by kworker/0:2/775:
 #0: ffff88802147cd48 ((wq_completion)dio/loop0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88802147cd48 ((wq_completion)dio/loop0){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1810 kernel/workqueue.c:3312
 #1: ffffc9000379fd20 ((work_completion)(&dio->complete_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000379fd20 ((work_completion)(&dio->complete_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1810 kernel/workqueue.c:3312
 #2: ffff8880698a8fa8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
 #2: ffff8880698a8fa8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: hfs_file_fsync+0x98/0x140 fs/hfs/inode.c:671
 #3: ffffffff8dd314a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #3: ffffffff8dd314a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #3: ffffffff8dd314a0 (rcu_read_lock){....}-{1:2}, at: start_flush_work kernel/workqueue.c:4122 [inline]
 #3: ffffffff8dd314a0 (rcu_read_lock){....}-{1:2}, at: __flush_work+0xe6/0xd00 kernel/workqueue.c:4181
 #4: ffff8880b943df18 (&pool->lock){-.-.}-{2:2}, at: start_flush_work kernel/workqueue.c:4129 [inline]
 #4: ffff8880b943df18 (&pool->lock){-.-.}-{2:2}, at: __flush_work+0x1a8/0xd00 kernel/workqueue.c:4181
 #5: ffffffff8dc0cf60 (console_lock){+.+.}-{0:0}, at: _printk+0xd5/0x120 kernel/printk/printk.c:2370
 #6: ffffffff8dc0cb90 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:334 [inline]
 #6: ffffffff8dc0cb90 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
 #6: ffffffff8dc0cb90 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline]
 #6: ffffffff8dc0cb90 (console_srcu){....}-{0:0}, at: console_flush_all+0x152/0xfc0 kernel/printk/printk.c:2986

stack backtrace:
CPU: 0 PID: 775 Comm: kworker/0:2 Not tainted 6.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: dio/loop0 dio_aio_complete_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x379/0x4b0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x3a63/0x8010 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x540 kernel/locking/lockdep.c:5754
 console_lock_spinning_enable kernel/printk/printk.c:1870 [inline]
 console_emit_next_record kernel/printk/printk.c:2922 [inline]
 console_flush_all+0x810/0xfc0 kernel/printk/printk.c:2994
 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3063
 vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2345
 _printk+0xd5/0x120 kernel/printk/printk.c:2370
 __warn_printk+0x237/0x360 kernel/panic.c:737
 check_flush_dependency+0x2b0/0x350 kernel/workqueue.c:3706
 start_flush_work kernel/workqueue.c:4143 [inline]
 __flush_work+0x286/0xd00 kernel/workqueue.c:4181
 flush_work kernel/workqueue.c:4232 [inline]
 flush_delayed_work+0x169/0x1c0 kernel/workqueue.c:4254
 hfs_file_fsync+0xed/0x140 fs/hfs/inode.c:678
 generic_write_sync include/linux/fs.h:2794 [inline]
 dio_complete+0x567/0x6c0 fs/direct-io.c:314
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1810 kernel/workqueue.c:3312
 worker_thread+0xa60/0xff0 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
workqueue: WQ_MEM_RECLAIM dio/loop0:dio_aio_complete_work is flushing !WQ_MEM_RECLAIM events_long:flush_mdb
WARNING: CPU: 0 PID: 775 at kernel/workqueue.c:3710 check_flush_dependency+0x2b0/0x350 kernel/workqueue.c:3706
Modules linked in:
CPU: 0 PID: 775 Comm: kworker/0:2 Not tainted 6.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: dio/loop0 dio_aio_complete_work
RIP: 0010:check_flush_dependency+0x2b0/0x350 kernel/workqueue.c:3706
Code: 08 4c 89 e7 e8 51 3b 98 00 49 8b 14 24 49 81 c7 70 01 00 00 48 c7 c7 40 db 69 8b 4c 89 ee 4c 89 f9 4c 8b 04 24 e8 80 80 f8 ff <0f> 0b eb 9b 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a7 fd ff ff 48 89
RSP: 0018:ffffc9000379f880 EFLAGS: 00010046
RAX: 130e7eafc3138d00 RBX: ffff88802147cdc0 RCX: ffff88801ec33c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000008 R08: ffffffff8156c262 R09: 1ffff1101728519a
R10: dffffc0000000000 R11: ffffed101728519b R12: ffff88801ed36f18
R13: ffff88802147cd70 R14: dffffc0000000000 R15: ffff888014e41170
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a99580cc78 CR3: 000000007aa34000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 start_flush_work kernel/workqueue.c:4143 [inline]
 __flush_work+0x286/0xd00 kernel/workqueue.c:4181
 flush_work kernel/workqueue.c:4232 [inline]
 flush_delayed_work+0x169/0x1c0 kernel/workqueue.c:4254
 hfs_file_fsync+0xed/0x140 fs/hfs/inode.c:678
 generic_write_sync include/linux/fs.h:2794 [inline]
 dio_complete+0x567/0x6c0 fs/direct-io.c:314
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1810 kernel/workqueue.c:3312
 worker_thread+0xa60/0xff0 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>