EEVDF scheduling fail, picking leftmost ====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc4-next-20231005-syzkaller-09984-g7d730f1bf6f3 #0 Not tainted ------------------------------------------------------ kworker/u4:8/2820 is trying to acquire lock: ffffffff8d5201e0 (console_owner){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] ffffffff8d5201e0 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline] ffffffff8d5201e0 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline] ffffffff8d5201e0 (console_owner){....}-{0:0}, at: console_flush_all+0x154/0xec0 kernel/printk/printk.c:2952 but task is already holding lock: ffff8880b993c318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 raw_spin_rq_lock kernel/sched/sched.h:1357 [inline] rq_lock kernel/sched/sched.h:1671 [inline] task_fork_fair+0x61/0x1e0 kernel/sched/fair.c:12399 sched_cgroup_fork+0x37b/0x410 kernel/sched/core.c:4799 copy_process+0x27b0/0x3fb0 kernel/fork.c:2609 kernel_clone+0x222/0x840 kernel/fork.c:2907 user_mode_thread+0x132/0x190 kernel/fork.c:2985 rest_init+0x27/0x300 init/main.c:691 arch_call_rest_init+0xe/0x10 init/main.c:823 start_kernel+0x46e/0x4f0 init/main.c:1068 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0x167/0x16b -> #3 (&p->pi_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 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] try_to_wake_up+0xb5/0x1440 kernel/sched/core.c:4213 __wake_up_common+0x2a0/0x4e0 kernel/sched/wait.c:107 __wake_up_common_lock kernel/sched/wait.c:138 [inline] __wake_up+0x11e/0x1d0 kernel/sched/wait.c:160 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6b7/0x8b0 drivers/tty/serial/8250/8250_port.c:1842 serial8250_handle_irq+0x549/0x700 drivers/tty/serial/8250/8250_port.c:1949 serial8250_default_handle_irq+0xcc/0x1e0 drivers/tty/serial/8250/8250_port.c:1969 serial8250_interrupt+0xa5/0x1e0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x286/0xa20 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+0x249/0xbf0 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x134/0x220 arch/x86/kernel/irq.c:257 common_interrupt+0xa3/0xc0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 lock_release+0x51/0x9d0 kernel/locking/lockdep.c:5761 up_write+0x79/0x580 kernel/locking/rwsem.c:1631 kernfs_add_one+0x424/0x8a0 fs/kernfs/dir.c:788 kernfs_create_dir_ns+0x1c4/0x230 fs/kernfs/dir.c:1050 sysfs_create_dir_ns+0x189/0x390 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x61d/0xc30 lib/kobject.c:238 kobject_add_varg lib/kobject.c:372 [inline] kobject_add+0x152/0x210 lib/kobject.c:424 device_add+0x4b5/0xd30 drivers/base/core.c:3562 netdev_register_kobject+0x17a/0x310 net/core/net-sysfs.c:2044 register_netdevice+0xcd6/0x1510 net/core/dev.c:10158 bpq_new_device drivers/net/hamradio/bpqether.c:499 [inline] bpq_device_event+0x489/0x8b0 drivers/net/hamradio/bpqether.c:542 notifier_call_chain+0x18c/0x3a0 kernel/notifier.c:93 __dev_notify_flags+0x359/0x650 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8674 devinet_ioctl+0xab8/0x1bc0 net/ipv4/devinet.c:1167 inet_ioctl+0x3e5/0x500 net/ipv4/af_inet.c:990 sock_do_ioctl+0x152/0x460 net/socket.c:1220 sock_ioctl+0x610/0x8c0 net/socket.c:1339 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #2 (&tty->write_wait){-.-.}-{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 __wake_up_common_lock kernel/sched/wait.c:137 [inline] __wake_up+0x101/0x1d0 kernel/sched/wait.c:160 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6b7/0x8b0 drivers/tty/serial/8250/8250_port.c:1842 serial8250_handle_irq+0x549/0x700 drivers/tty/serial/8250/8250_port.c:1949 serial8250_default_handle_irq+0xcc/0x1e0 drivers/tty/serial/8250/8250_port.c:1969 serial8250_interrupt+0xa5/0x1e0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x286/0xa20 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+0x249/0xbf0 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x134/0x220 arch/x86/kernel/irq.c:257 common_interrupt+0xa3/0xc0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 clear_page_erms+0xb/0x10 arch/x86/lib/clear_page_64.S:49 clear_page arch/x86/include/asm/page_64.h:53 [inline] clear_highpage_kasan_tagged include/linux/highmem.h:248 [inline] kernel_init_pages mm/page_alloc.c:1069 [inline] post_alloc_hook+0xf8/0x210 mm/page_alloc.c:1532 prep_new_page mm/page_alloc.c:1541 [inline] get_page_from_freelist+0x33aa/0x3530 mm/page_alloc.c:3333 __alloc_pages+0x255/0x670 mm/page_alloc.c:4589 alloc_pages_mpol+0x3de/0x640 mm/mempolicy.c:2153 vm_area_alloc_pages mm/vmalloc.c:3063 [inline] __vmalloc_area_node mm/vmalloc.c:3139 [inline] __vmalloc_node_range+0x9a3/0x1490 mm/vmalloc.c:3320 alloc_thread_stack_node kernel/fork.c:309 [inline] dup_task_struct+0x3e5/0x7d0 kernel/fork.c:1118 copy_process+0x5d1/0x3fb0 kernel/fork.c:2332 kernel_clone+0x222/0x840 kernel/fork.c:2907 user_mode_thread+0x132/0x190 kernel/fork.c:2985 call_usermodehelper_exec_sync kernel/umh.c:133 [inline] call_usermodehelper_exec_work+0x97/0x220 kernel/umh.c:164 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x90f/0x1400 kernel/workqueue.c:2703 worker_thread+0xa5f/0xff0 kernel/workqueue.c:2784 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> #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:616 [inline] serial8250_console_write+0x1a8/0x1820 drivers/tty/serial/8250/8250_port.c:3410 console_emit_next_record kernel/printk/printk.c:2894 [inline] console_flush_all+0x7ff/0xec0 kernel/printk/printk.c:2960 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3029 vprintk_emit+0x508/0x720 kernel/printk/printk.c:2304 _printk+0xd5/0x120 kernel/printk/printk.c:2329 register_console+0x705/0xcc0 kernel/printk/printk.c:3535 univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717 console_init+0x193/0x670 kernel/printk/printk.c:3681 start_kernel+0x2d2/0x4f0 init/main.c:1004 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0x167/0x16b -> #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:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 console_lock_spinning_enable kernel/printk/printk.c:1855 [inline] console_emit_next_record kernel/printk/printk.c:2888 [inline] console_flush_all+0x7b2/0xec0 kernel/printk/printk.c:2960 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3029 vprintk_emit+0x508/0x720 kernel/printk/printk.c:2304 _printk+0xd5/0x120 kernel/printk/printk.c:2329 pick_eevdf+0x660/0x690 kernel/sched/fair.c:963 pick_next_entity kernel/sched/fair.c:5247 [inline] pick_next_task_fair+0x122/0xdc0 kernel/sched/fair.c:8205 __pick_next_task kernel/sched/core.c:5986 [inline] pick_next_task kernel/sched/core.c:6061 [inline] __schedule+0x7c7/0x4b00 kernel/sched/core.c:6640 __schedule_loop kernel/sched/core.c:6753 [inline] schedule+0x149/0x260 kernel/sched/core.c:6768 worker_thread+0xc26/0xff0 kernel/workqueue.c:2799 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 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 *** 3 locks held by kworker/u4:8/2820: #0: ffff8880b993c318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffffffff8d407b00 (console_lock){+.+.}-{0:0}, at: _printk+0xd5/0x120 kernel/printk/printk.c:2329 #2: ffffffff8d407730 (console_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] #2: ffffffff8d407730 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline] #2: ffffffff8d407730 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline] #2: ffffffff8d407730 (console_srcu){....}-{0:0}, at: console_flush_all+0x154/0xec0 kernel/printk/printk.c:2952 stack backtrace: CPU: 1 PID: 2820 Comm: kworker/u4:8 Not tainted 6.6.0-rc4-next-20231005-syzkaller-09984-g7d730f1bf6f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: 0x0 (bat_events) Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x375/0x4a0 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:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 console_lock_spinning_enable kernel/printk/printk.c:1855 [inline] console_emit_next_record kernel/printk/printk.c:2888 [inline] console_flush_all+0x7b2/0xec0 kernel/printk/printk.c:2960 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3029 vprintk_emit+0x508/0x720 kernel/printk/printk.c:2304 _printk+0xd5/0x120 kernel/printk/printk.c:2329 pick_eevdf+0x660/0x690 kernel/sched/fair.c:963 pick_next_entity kernel/sched/fair.c:5247 [inline] pick_next_task_fair+0x122/0xdc0 kernel/sched/fair.c:8205 __pick_next_task kernel/sched/core.c:5986 [inline] pick_next_task kernel/sched/core.c:6061 [inline] __schedule+0x7c7/0x4b00 kernel/sched/core.c:6640 __schedule_loop kernel/sched/core.c:6753 [inline] schedule+0x149/0x260 kernel/sched/core.c:6768 worker_thread+0xc26/0xff0 kernel/workqueue.c:2799 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304