EEVDF scheduling fail, picking leftmost ====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc4-next-20231005-syzkaller-09984-g7d730f1bf6f3 #0 Not tainted ------------------------------------------------------ syz-executor.0/5636 is trying to acquire lock: ffffffff8c994ed8 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 but task is already holding lock: ffff88806b73c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:558 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 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+0x70/0x240 kernel/sched/fair.c:12399 sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4799 copy_process+0x4562/0x7490 kernel/fork.c:2609 kernel_clone+0xe9/0x920 kernel/fork.c:2907 user_mode_thread+0xb4/0xf0 kernel/fork.c:2985 rest_init+0x27/0x2b0 init/main.c:691 arch_call_rest_init+0x13/0x30 init/main.c:823 start_kernel+0x397/0x470 init/main.c:1068 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0x166/0x16b -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] try_to_wake_up+0xb3/0x1600 kernel/sched/core.c:4213 up+0x79/0xb0 kernel/locking/semaphore.c:191 __up_console_sem kernel/printk/printk.c:340 [inline] __console_unlock kernel/printk/printk.c:2699 [inline] console_unlock+0x1c1/0x250 kernel/printk/printk.c:3031 vga_remove_vgacon drivers/pci/vgaarb.c:186 [inline] vga_remove_vgacon+0x8c/0xd0 drivers/pci/vgaarb.c:167 __aperture_remove_legacy_vga_devices drivers/video/aperture.c:331 [inline] aperture_remove_conflicting_pci_devices+0x17b/0x210 drivers/video/aperture.c:374 virtio_gpu_pci_quirk drivers/gpu/drm/virtio/virtgpu_drv.c:61 [inline] virtio_gpu_probe+0x302/0x3b0 drivers/gpu/drm/virtio/virtgpu_drv.c:92 virtio_dev_probe+0x56c/0x870 drivers/virtio/virtio.c:305 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x234/0xc90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x4b0 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830 __driver_attach+0x274/0x570 drivers/base/dd.c:1216 bus_for_each_dev+0x12a/0x1b0 drivers/base/bus.c:368 bus_add_driver+0x2e9/0x630 drivers/base/bus.c:673 driver_register+0x15c/0x4a0 drivers/base/driver.c:246 do_one_initcall+0x10a/0x640 init/main.c:1232 do_initcall_level init/main.c:1294 [inline] do_initcalls init/main.c:1310 [inline] do_basic_setup init/main.c:1329 [inline] kernel_init_freeable+0x5c2/0x900 init/main.c:1547 kernel_init+0x1c/0x2a0 init/main.c:1437 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> #0 ((console_sem).lock){-...}-{2:2}: 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+0x2e3d/0x5de0 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:323 console_trylock+0x73/0x130 kernel/printk/printk.c:2652 console_trylock_spinning kernel/printk/printk.c:1924 [inline] vprintk_emit+0x162/0x5f0 kernel/printk/printk.c:2303 vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45 _printk+0xbf/0xf0 kernel/printk/printk.c:2329 pick_eevdf kernel/sched/fair.c:963 [inline] check_preempt_wakeup_fair+0x553/0x640 kernel/sched/fair.c:8108 wakeup_preempt+0x125/0x320 kernel/sched/core.c:2217 ttwu_do_activate+0x24f/0xd90 kernel/sched/core.c:3767 ttwu_queue kernel/sched/core.c:4008 [inline] try_to_wake_up+0x6a7/0x1600 kernel/sched/core.c:4329 signal_wake_up_state+0x79/0x120 kernel/signal.c:782 signal_wake_up include/linux/sched/signal.h:448 [inline] zap_other_threads+0x205/0x360 kernel/signal.c:1394 do_group_exit+0x268/0x2a0 kernel/exit.c:1016 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock((console_sem).lock); *** DEADLOCK *** 3 locks held by syz-executor.0/5636: #0: ffff88801f506358 (&sighand->siglock){....}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #0: ffff88801f506358 (&sighand->siglock){....}-{2:2}, at: do_group_exit+0x146/0x2a0 kernel/exit.c:1007 #1: ffff8880229a8fb8 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] #1: ffff8880229a8fb8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb3/0x1600 kernel/sched/core.c:4213 #2: ffff88806b73c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:558 stack backtrace: CPU: 3 PID: 5636 Comm: syz-executor.0 Not tainted 6.6.0-rc4-next-20231005-syzkaller-09984-g7d730f1bf6f3 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 check_noncircular+0x2f7/0x3d0 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+0x2e3d/0x5de0 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:323 console_trylock+0x73/0x130 kernel/printk/printk.c:2652 console_trylock_spinning kernel/printk/printk.c:1924 [inline] vprintk_emit+0x162/0x5f0 kernel/printk/printk.c:2303 vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45 _printk+0xbf/0xf0 kernel/printk/printk.c:2329 pick_eevdf kernel/sched/fair.c:963 [inline] check_preempt_wakeup_fair+0x553/0x640 kernel/sched/fair.c:8108 wakeup_preempt+0x125/0x320 kernel/sched/core.c:2217 ttwu_do_activate+0x24f/0xd90 kernel/sched/core.c:3767 ttwu_queue kernel/sched/core.c:4008 [inline] try_to_wake_up+0x6a7/0x1600 kernel/sched/core.c:4329 signal_wake_up_state+0x79/0x120 kernel/signal.c:782 signal_wake_up include/linux/sched/signal.h:448 [inline] zap_other_threads+0x205/0x360 kernel/signal.c:1394 do_group_exit+0x268/0x2a0 kernel/exit.c:1016 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6f6947cb29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdb41e9d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007f6f6947cb29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 00007f6f6959bf8c R09: 0000000000000000 R10: 0000001b2d560000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000