ODEBUG: object ffffc90004c4fb90 is on stack ffffc90004c48000, but NOT annotated. ====================================================== WARNING: possible circular locking dependency detected 6.15.0-syzkaller-02198-gb1456f6dc167 #0 Not tainted ------------------------------------------------------ bch-copygc/loop/6488 is trying to acquire lock: ffffffff8df30be0 (console_owner){-...}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:2048 [inline] ffffffff8df30be0 (console_owner){-...}-{0:0}, at: vprintk_emit+0x444/0x7a0 kernel/printk/printk.c:2449 but task is already holding lock: ffffffff99a82098 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_object_init+0x85/0x3c0 lib/debugobjects.c:741 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&obj_hash[i].lock){-.-.}-{2:2}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818 debug_work_activate kernel/workqueue.c:664 [inline] insert_work+0x35/0x330 kernel/workqueue.c:2180 __queue_work+0xcfc/0xfe0 kernel/workqueue.c:2341 queue_work_on+0x181/0x270 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:662 [inline] start_poll_synchronize_rcu_expedited+0xfc/0x140 kernel/rcu/tree_exp.h:1075 rcu_init+0x108/0x160 kernel/rcu/tree.c:4854 start_kernel+0x1fb/0x500 init/main.c:990 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 -> #3 (&pool->lock){-.-.}-{2:2}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __queue_work+0x7b0/0xfe0 kernel/workqueue.c:-1 queue_work_on+0x181/0x270 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:662 [inline] rpm_suspend+0xe54/0x1720 drivers/base/power/runtime.c:673 __pm_runtime_idle+0x12f/0x1a0 drivers/base/power/runtime.c:1112 pm_runtime_put include/linux/pm_runtime.h:466 [inline] __device_attach+0x342/0x400 drivers/base/dd.c:1047 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3692 serial_base_port_add+0x2f2/0x430 drivers/tty/serial/serial_base_bus.c:179 serial_core_port_device_add drivers/tty/serial/serial_core.c:3342 [inline] serial_core_register_port+0x367/0x2700 drivers/tty/serial/serial_core.c:3381 serial8250_register_8250_port+0x16dc/0x2050 drivers/tty/serial/8250/8250_core.c:822 serial_pnp_probe+0x527/0x790 drivers/tty/serial/8250/8250_pnp.c:480 pnp_device_probe+0x308/0x4c0 drivers/pnp/driver.c:111 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26a/0x9a0 drivers/base/dd.c:657 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829 __driver_attach+0x452/0x700 drivers/base/dd.c:1215 bus_for_each_dev+0x230/0x2b0 drivers/base/bus.c:370 bus_add_driver+0x345/0x640 drivers/base/bus.c:678 driver_register+0x23a/0x320 drivers/base/driver.c:249 serial8250_init+0xc2/0x1c0 drivers/tty/serial/8250/8250_platform.c:315 do_one_initcall+0x233/0x820 init/main.c:1257 do_initcall_level+0x137/0x1f0 init/main.c:1319 do_initcalls+0x69/0xd0 init/main.c:1335 kernel_init_freeable+0x3d9/0x570 init/main.c:1567 kernel_init+0x1d/0x1d0 init/main.c:1457 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (&dev->power.lock){-.-.}-{3:3}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 __pm_runtime_resume+0x10f/0x180 drivers/base/power/runtime.c:1179 pm_runtime_get include/linux/pm_runtime.h:414 [inline] __uart_start+0x171/0x440 drivers/tty/serial/serial_core.c:148 uart_write+0x278/0xa40 drivers/tty/serial/serial_core.c:635 process_output_block drivers/tty/n_tty.c:561 [inline] n_tty_write+0xd32/0x11d0 drivers/tty/n_tty.c:2377 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write+0x4fe/0x990 drivers/tty/tty_io.c:1090 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&port_lock_key){-.-.}-{3:3}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] serial8250_console_write+0x17e/0x1ba0 drivers/tty/serial/8250/8250_port.c:3415 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 register_console+0xa8b/0xf90 kernel/printk/printk.c:4125 univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513 console_init+0x1a1/0x670 kernel/printk/printk.c:4323 start_kernel+0x2cc/0x500 init/main.c:1034 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 -> #0 (console_owner){-...}-{0:0}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 console_trylock_spinning kernel/printk/printk.c:2048 [inline] vprintk_emit+0x460/0x7a0 kernel/printk/printk.c:2449 _printk+0xcf/0x120 kernel/printk/printk.c:2475 debug_object_is_on_stack lib/debugobjects.c:-1 [inline] lookup_object_or_alloc lib/debugobjects.c:688 [inline] __debug_object_init+0x2c8/0x3c0 lib/debugobjects.c:743 rhashtable_init_noprof+0x7c0/0xbb0 lib/rhashtable.c:1085 bch2_copygc_thread+0x116/0xdc0 fs/bcachefs/movinggc.c:355 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Chain exists of: console_owner --> &pool->lock --> &obj_hash[i].lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&obj_hash[i].lock); lock(&pool->lock); lock(&obj_hash[i].lock); lock(console_owner); *** DEADLOCK *** 1 lock held by bch-copygc/loop/6488: #0: ffffffff99a82098 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_object_init+0x85/0x3c0 lib/debugobjects.c:741 stack backtrace: CPU: 0 UID: 0 PID: 6488 Comm: bch-copygc/loop Not tainted 6.15.0-syzkaller-02198-gb1456f6dc167 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 console_trylock_spinning kernel/printk/printk.c:2048 [inline] vprintk_emit+0x460/0x7a0 kernel/printk/printk.c:2449 _printk+0xcf/0x120 kernel/printk/printk.c:2475 debug_object_is_on_stack lib/debugobjects.c:-1 [inline] lookup_object_or_alloc lib/debugobjects.c:688 [inline] __debug_object_init+0x2c8/0x3c0 lib/debugobjects.c:743 rhashtable_init_noprof+0x7c0/0xbb0 lib/rhashtable.c:1085 bch2_copygc_thread+0x116/0xdc0 fs/bcachefs/movinggc.c:355 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 6488 at lib/debugobjects.c:655 debug_object_is_on_stack lib/debugobjects.c:655 [inline] WARNING: CPU: 0 PID: 6488 at lib/debugobjects.c:655 lookup_object_or_alloc lib/debugobjects.c:688 [inline] WARNING: CPU: 0 PID: 6488 at lib/debugobjects.c:655 __debug_object_init+0x2c9/0x3c0 lib/debugobjects.c:743 Modules linked in: CPU: 0 UID: 0 PID: 6488 Comm: bch-copygc/loop Not tainted 6.15.0-syzkaller-02198-gb1456f6dc167 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:debug_object_is_on_stack lib/debugobjects.c:655 [inline] RIP: 0010:lookup_object_or_alloc lib/debugobjects.c:688 [inline] RIP: 0010:__debug_object_init+0x2c9/0x3c0 lib/debugobjects.c:743 Code: cc cc cc 41 ff c7 44 89 3d 64 28 f6 14 48 c7 c1 c0 81 c1 8b 48 c7 c7 20 82 c1 8b 84 c0 48 0f 45 f9 48 89 de e8 a8 50 6a fc 90 <0f> 0b 90 e9 c0 fe ff ff e8 3a 1c 00 00 8b 05 dc 12 ae 09 3b 05 da RSP: 0018:ffffc90004c4f6e0 EFLAGS: 00010046 RAX: 0000000000000050 RBX: ffffc90004c4fb90 RCX: dee006bb47c65600 RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 RBP: ffff88802fd98020 R08: ffffffff8df30b83 R09: 1ffffffff1be6170 R10: dffffc0000000000 R11: fffffbfff1be6171 R12: 0000000000000040 R13: ffff888035a17000 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881260c7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563e95ab6950 CR3: 0000000065a42000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rhashtable_init_noprof+0x7c0/0xbb0 lib/rhashtable.c:1085 bch2_copygc_thread+0x116/0xdc0 fs/bcachefs/movinggc.c:355 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245