------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-05491-g5d066766c5f1 #0 Not tainted ------------------------------------------------------ kworker/1:1/80 is trying to acquire lock: ffffffff8ea17d80 (console_owner){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline] ffffffff8ea17d80 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:297 [inline] ffffffff8ea17d80 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline] ffffffff8ea17d80 (console_owner){....}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3187 but task is already holding lock: ffff8880b873e8d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 raw_spin_rq_lock kernel/sched/sched.h:1514 [inline] task_rq_lock+0xc6/0x360 kernel/sched/core.c:700 cgroup_move_task+0x9b/0x5a0 kernel/sched/psi.c:1161 css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:898 cgroup_post_fork+0x256/0x880 kernel/cgroup/cgroup.c:6691 copy_process+0x39e9/0x3d50 kernel/fork.c:2601 kernel_clone+0x226/0x8f0 kernel/fork.c:2787 user_mode_thread+0x132/0x1a0 kernel/fork.c:2865 rest_init+0x23/0x300 init/main.c:712 start_kernel+0x47f/0x500 init/main.c:1102 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147 -> #3 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4205 __wake_up_common kernel/sched/wait.c:89 [inline] __wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1840 serial8250_handle_irq+0x630/0xb80 drivers/tty/serial/8250/8250_port.c:1948 serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1968 serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x29a/0xa80 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210 handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:247 [inline] call_irq_handler arch/x86/kernel/irq.c:259 [inline] __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285 common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111 acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:264 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:385 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x372/0x5c0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 rest_init+0x2dc/0x300 init/main.c:747 start_kernel+0x47f/0x500 init/main.c:1102 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147 -> #2 (&tty->write_wait){-.-.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __wake_up_common_lock+0x25/0x1e0 kernel/sched/wait.c:105 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1840 serial8250_handle_irq+0x630/0xb80 drivers/tty/serial/8250/8250_port.c:1948 serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1968 serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x29a/0xa80 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210 handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:247 [inline] call_irq_handler arch/x86/kernel/irq.c:259 [inline] __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285 common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] uart_port_unlock_irqrestore include/linux/serial_core.h:786 [inline] uart_write+0x3e4/0xa40 drivers/tty/serial/serial_core.c:636 process_output_block drivers/tty/n_tty.c:574 [inline] n_tty_write+0xd62/0x1230 drivers/tty/n_tty.c:2389 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write+0x546/0x9b0 drivers/tty/tty_io.c:1090 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&port_lock_key){-.-.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __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:715 [inline] serial8250_console_write+0x1a7/0x1ed0 drivers/tty/serial/8250/8250_port.c:3371 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x86b/0xeb0 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432 _printk+0xd5/0x120 kernel/printk/printk.c:2457 register_console+0xbf5/0xfd0 kernel/printk/printk.c:4099 univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513 console_init+0x1b8/0x6f0 kernel/printk/printk.c:4292 start_kernel+0x2d8/0x500 init/main.c:1037 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147 -> #0 (console_owner){....}-{0:0}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 console_lock_spinning_enable kernel/printk/printk.c:1924 [inline] console_emit_next_record kernel/printk/printk.c:3116 [inline] console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432 _printk+0xd5/0x120 kernel/printk/printk.c:2457 __report_bug lib/bug.c:195 [inline] report_bug+0x346/0x500 lib/bug.c:219 handle_bug+0x60/0x90 arch/x86/kernel/traps.c:285 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:309 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995 dl_server_start+0xc9/0x240 kernel/sched/deadline.c:1650 enqueue_task_fair+0xb5c/0xea0 kernel/sched/fair.c:7038 enqueue_task+0x72/0x330 kernel/sched/core.c:2061 activate_task+0x61/0xc0 kernel/sched/core.c:2108 attach_task+0xee/0x190 kernel/sched/fair.c:9635 attach_tasks kernel/sched/fair.c:9670 [inline] sched_balance_rq+0x664a/0x8620 kernel/sched/fair.c:11747 sched_balance_newidle+0x6ba/0xfd0 kernel/sched/fair.c:12789 pick_next_task_fair+0x40/0xc90 kernel/sched/fair.c:8937 __pick_next_task+0xdd/0x400 kernel/sched/core.c:6023 __schedule+0x776/0x4c30 kernel/sched/core.c:6709 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 worker_thread+0xa30/0xd30 kernel/workqueue.c:3406 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 --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock(console_owner); *** DEADLOCK *** 4 locks held by kworker/1:1/80: #0: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: sched_balance_newidle+0x2c0/0xfd0 kernel/sched/fair.c:12759 #1: ffff8880b873e8d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #2: ffffffff8ea17de0 (console_lock){+.+.}-{0:0}, at: _printk+0xd5/0x120 kernel/printk/printk.c:2457 #3: ffffffff8ea179f0 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline] #3: ffffffff8ea179f0 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:297 [inline] #3: ffffffff8ea179f0 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline] #3: ffffffff8ea179f0 (console_srcu){....}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3187 stack backtrace: CPU: 1 UID: 0 PID: 80 Comm: kworker/1:1 Not tainted 6.12.0-syzkaller-05491-g5d066766c5f1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: 0x0 (mm_percpu_wq) Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 console_lock_spinning_enable kernel/printk/printk.c:1924 [inline] console_emit_next_record kernel/printk/printk.c:3116 [inline] console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432 _printk+0xd5/0x120 kernel/printk/printk.c:2457 __report_bug lib/bug.c:195 [inline] report_bug+0x346/0x500 lib/bug.c:219 handle_bug+0x60/0x90 arch/x86/kernel/traps.c:285 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:309 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 RIP: 0010:enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995 Code: df 0f b6 04 08 84 c0 0f 85 cf 02 00 00 8b 75 00 48 89 df 4c 89 ea 48 83 c4 58 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d1 1f ff ff 90 <0f> 0b 90 e9 09 ea ff ff 90 0f 0b 90 e9 c4 fb ff ff 90 0f 0b 90 e9 RSP: 0018:ffffc9000238f130 EFLAGS: 00010017 RAX: dffffc0000000000 RBX: ffff8880b873f2c0 RCX: 1ffff110170e7e55 RDX: ffffffff816898a0 RSI: 0000000000000001 RDI: ffff8880b873f2a8 RBP: 0000000000000001 R08: ffff88801e293ca7 R09: 0000000000000000 R10: ffff88801e293c90 R11: ffffed1003c52795 R12: ffff8880b873f2a8 R13: ffff8880b873f2a8 R14: ffff8880b873f2fc R15: ffff8880b873f380 dl_server_start+0xc9/0x240 kernel/sched/deadline.c:1650 enqueue_task_fair+0xb5c/0xea0 kernel/sched/fair.c:7038 enqueue_task+0x72/0x330 kernel/sched/core.c:2061 activate_task+0x61/0xc0 kernel/sched/core.c:2108 attach_task+0xee/0x190 kernel/sched/fair.c:9635 attach_tasks kernel/sched/fair.c:9670 [inline] sched_balance_rq+0x664a/0x8620 kernel/sched/fair.c:11747 sched_balance_newidle+0x6ba/0xfd0 kernel/sched/fair.c:12789 pick_next_task_fair+0x40/0xc90 kernel/sched/fair.c:8937 __pick_next_task+0xdd/0x400 kernel/sched/core.c:6023 __schedule+0x776/0x4c30 kernel/sched/core.c:6709 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 worker_thread+0xa30/0xd30 kernel/workqueue.c:3406 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 WARNING: CPU: 1 PID: 80 at kernel/sched/deadline.c:1995 enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995 Modules linked in: CPU: 1 UID: 0 PID: 80 Comm: kworker/1:1 Not tainted 6.12.0-syzkaller-05491-g5d066766c5f1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: 0x0 (mm_percpu_wq) RIP: 0010:enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995 Code: df 0f b6 04 08 84 c0 0f 85 cf 02 00 00 8b 75 00 48 89 df 4c 89 ea 48 83 c4 58 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d1 1f ff ff 90 <0f> 0b 90 e9 09 ea ff ff 90 0f 0b 90 e9 c4 fb ff ff 90 0f 0b 90 e9 RSP: 0018:ffffc9000238f130 EFLAGS: 00010017 RAX: dffffc0000000000 RBX: ffff8880b873f2c0 RCX: 1ffff110170e7e55 RDX: ffffffff816898a0 RSI: 0000000000000001 RDI: ffff8880b873f2a8 RBP: 0000000000000001 R08: ffff88801e293ca7 R09: 0000000000000000 R10: ffff88801e293c90 R11: ffffed1003c52795 R12: ffff8880b873f2a8 R13: ffff8880b873f2a8 R14: ffff8880b873f2fc R15: ffff8880b873f380 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc75b8fff8 CR3: 000000000e938000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dl_server_start+0xc9/0x240 kernel/sched/deadline.c:1650 enqueue_task_fair+0xb5c/0xea0 kernel/sched/fair.c:7038 enqueue_task+0x72/0x330 kernel/sched/core.c:2061 activate_task+0x61/0xc0 kernel/sched/core.c:2108 attach_task+0xee/0x190 kernel/sched/fair.c:9635 attach_tasks kernel/sched/fair.c:9670 [inline] sched_balance_rq+0x664a/0x8620 kernel/sched/fair.c:11747 sched_balance_newidle+0x6ba/0xfd0 kernel/sched/fair.c:12789 pick_next_task_fair+0x40/0xc90 kernel/sched/fair.c:8937 __pick_next_task+0xdd/0x400 kernel/sched/core.c:6023 __schedule+0x776/0x4c30 kernel/sched/core.c:6709 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 worker_thread+0xa30/0xd30 kernel/workqueue.c:3406 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