------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc2-syzkaller-gd3fa86b1a7b4 #0 Not tainted
------------------------------------------------------
syz-executor.0/5977 is trying to acquire lock:
ffffffff8cf95d38 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff88806b63c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:566 [inline]
ffff88806b63c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:551

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:1349 [inline]
       rq_lock kernel/sched/sched.h:1663 [inline]
       task_fork_fair+0x70/0x240 kernel/sched/fair.c:12586
       sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4812
       copy_process+0x4c86/0x73f0 kernel/fork.c:2609
       kernel_clone+0xfd/0x930 kernel/fork.c:2907
       user_mode_thread+0xb4/0xf0 kernel/fork.c:2985
       rest_init+0x27/0x2b0 init/main.c:695
       arch_call_rest_init+0x13/0x30 init/main.c:827
       start_kernel+0x39f/0x480 init/main.c:1072
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:555
       x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:536
       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+0xb0/0x13d0 kernel/sched/core.c:4226
       up+0x79/0xb0 kernel/locking/semaphore.c:191
       __up_console_sem kernel/printk/printk.c:340 [inline]
       __console_unlock kernel/printk/printk.c:2706 [inline]
       console_unlock+0x1cf/0x260 kernel/printk/printk.c:3038
       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+0x31e/0x3c0 drivers/gpu/drm/virtio/virtgpu_drv.c:92
       virtio_dev_probe+0x56e/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+0x13c/0x1d0 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+0x11c/0x650 init/main.c:1236
       do_initcall_level init/main.c:1298 [inline]
       do_initcalls init/main.c:1314 [inline]
       do_basic_setup init/main.c:1333 [inline]
       kernel_init_freeable+0x687/0xc10 init/main.c:1551
       kernel_init+0x1c/0x2a0 init/main.c:1441
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

-> #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+0x2464/0x3b10 kernel/locking/lockdep.c:5136
       lock_acquire kernel/locking/lockdep.c:5753 [inline]
       lock_acquire+0x1ae/0x520 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:2659
       console_trylock_spinning kernel/printk/printk.c:1923 [inline]
       vprintk_emit+0x162/0x5f0 kernel/printk/printk.c:2302
       vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45
       _printk+0xc8/0x100 kernel/printk/printk.c:2328
       __report_bug lib/bug.c:195 [inline]
       report_bug+0x42f/0x580 lib/bug.c:219
       handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:237
       exc_invalid_op+0x17/0x40 arch/x86/kernel/traps.c:258
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:568
       lockdep_assert_rq_held kernel/sched/sched.h:1340 [inline]
       lockdep_assert_rq_held kernel/sched/sched.h:1338 [inline]
       rq_clock_pelt kernel/sched/pelt.h:66 [inline]
       cfs_rq_clock_pelt kernel/sched/pelt.h:174 [inline]
       update_load_avg+0x2c0/0x1eb0 kernel/sched/fair.c:4678
       set_next_entity+0x331/0x670 kernel/sched/fair.c:5373
       set_next_task_fair+0x88/0x320 kernel/sched/fair.c:12747
       set_next_task kernel/sched/sched.h:2287 [inline]
       pick_next_task kernel/sched/core.c:6104 [inline]
       __schedule+0x11e4/0x5af0 kernel/sched/core.c:6652
       preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6865
       preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
       __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
       _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
       spin_unlock include/linux/spinlock.h:391 [inline]
       zap_pte_range mm/memory.c:1534 [inline]
       zap_pmd_range mm/memory.c:1582 [inline]
       zap_pud_range mm/memory.c:1611 [inline]
       zap_p4d_range mm/memory.c:1632 [inline]
       unmap_page_range+0x13f0/0x2b50 mm/memory.c:1653
       unmap_single_vma+0x194/0x2b0 mm/memory.c:1699
       unmap_vmas+0x229/0x470 mm/memory.c:1743
       exit_mmap+0x1ad/0xa70 mm/mmap.c:3308
       __mmput+0x12a/0x4d0 kernel/fork.c:1349
       mmput+0x62/0x70 kernel/fork.c:1371
       exit_mm kernel/exit.c:567 [inline]
       do_exit+0x9ad/0x2ae0 kernel/exit.c:858
       do_group_exit+0xd4/0x2a0 kernel/exit.c:1021
       get_signal+0x23be/0x2790 kernel/signal.c:2904
       arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
       exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
       exit_to_user_mode_prepare+0x121/0x240 kernel/entry/common.c:204
       __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
       syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296
       do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

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.0/5977:
 #0: ffff88802219eba0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline]
 #0: ffff88802219eba0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x105/0xa70 mm/mmap.c:3293
 #1: ffffffff8cfa82e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline]
 #1: ffffffff8cfa82e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
 #1: ffffffff8cfa82e0 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x42/0x540 mm/pgtable-generic.c:285
 #2: ffff88806b63c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:566 [inline]
 #2: ffff88806b63c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:551

stack backtrace:
CPU: 1 PID: 5977 Comm: syz-executor.0 Not tainted 6.7.0-rc2-syzkaller-gd3fa86b1a7b4 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 check_noncircular+0x317/0x400 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+0x2464/0x3b10 kernel/locking/lockdep.c:5136
 lock_acquire kernel/locking/lockdep.c:5753 [inline]
 lock_acquire+0x1ae/0x520 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:2659
 console_trylock_spinning kernel/printk/printk.c:1923 [inline]
 vprintk_emit+0x162/0x5f0 kernel/printk/printk.c:2302
 vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45
 _printk+0xc8/0x100 kernel/printk/printk.c:2328
 __report_bug lib/bug.c:195 [inline]
 report_bug+0x42f/0x580 lib/bug.c:219
 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:237
 exc_invalid_op+0x17/0x40 arch/x86/kernel/traps.c:258
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:568
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1340 [inline]
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1338 [inline]
RIP: 0010:rq_clock_pelt kernel/sched/pelt.h:66 [inline]
RIP: 0010:cfs_rq_clock_pelt kernel/sched/pelt.h:174 [inline]
RIP: 0010:update_load_avg+0x2c0/0x1eb0 kernel/sched/fair.c:4678
Code: 00 41 8b b5 78 0d 00 00 4c 89 ef 85 f6 0f 85 f9 11 00 00 48 83 c7 18 be ff ff ff ff e8 b9 cf 21 09 85 c0 0f 85 fe fd ff ff 90 <0f> 0b 90 e9 f5 fd ff ff 49 8d bc 24 98 00 00 00 48 b8 00 00 00 00
RSP: 0018:ffffc90003e2f3c0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88801caa9800 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8accace0 RDI: ffffffff8b2ee640
RBP: ffff888025591980 R08: 0000000000000000 R09: 000000000000013c
R10: 0000000000000002 R11: 0000000000000002 R12: ffff888025591980
R13: ffff88806b83c740 R14: ffff88806b73d2a0 R15: ffff8880210e5af8
 set_next_entity+0x331/0x670 kernel/sched/fair.c:5373
 set_next_task_fair+0x88/0x320 kernel/sched/fair.c:12747
 set_next_task kernel/sched/sched.h:2287 [inline]
 pick_next_task kernel/sched/core.c:6104 [inline]
 __schedule+0x11e4/0x5af0 kernel/sched/core.c:6652
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6865
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1534 [inline]
 zap_pmd_range mm/memory.c:1582 [inline]
 zap_pud_range mm/memory.c:1611 [inline]
 zap_p4d_range mm/memory.c:1632 [inline]
 unmap_page_range+0x13f0/0x2b50 mm/memory.c:1653
 unmap_single_vma+0x194/0x2b0 mm/memory.c:1699
 unmap_vmas+0x229/0x470 mm/memory.c:1743
 exit_mmap+0x1ad/0xa70 mm/mmap.c:3308
 __mmput+0x12a/0x4d0 kernel/fork.c:1349
 mmput+0x62/0x70 kernel/fork.c:1371
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x9ad/0x2ae0 kernel/exit.c:858
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1021
 get_signal+0x23be/0x2790 kernel/signal.c:2904
 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x121/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296
 do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f6ed8c7cae9
Code: Unable to access opcode bytes at 0x7f6ed8c7cabf.
RSP: 002b:00007f6ed99a3178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f6ed8d9bf88 RCX: 00007f6ed8c7cae9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6ed8d9bf88
RBP: 00007f6ed8d9bf80 R08: 00007f6ed99a36c0 R09: 00007f6ed99a36c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6ed8d9bf8c
R13: 000000000000000b R14: 00007ffe2ee63990 R15: 00007ffe2ee63a78
 </TASK>
WARNING: CPU: 1 PID: 5977 at kernel/sched/sched.h:1340 lockdep_assert_rq_held kernel/sched/sched.h:1340 [inline]
WARNING: CPU: 1 PID: 5977 at kernel/sched/sched.h:1340 lockdep_assert_rq_held kernel/sched/sched.h:1338 [inline]
WARNING: CPU: 1 PID: 5977 at kernel/sched/sched.h:1340 rq_clock_pelt kernel/sched/pelt.h:66 [inline]
WARNING: CPU: 1 PID: 5977 at kernel/sched/sched.h:1340 cfs_rq_clock_pelt kernel/sched/pelt.h:174 [inline]
WARNING: CPU: 1 PID: 5977 at kernel/sched/sched.h:1340 update_load_avg+0x2c0/0x1eb0 kernel/sched/fair.c:4678
Modules linked in:
CPU: 1 PID: 5977 Comm: syz-executor.0 Not tainted 6.7.0-rc2-syzkaller-gd3fa86b1a7b4 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1340 [inline]
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1338 [inline]
RIP: 0010:rq_clock_pelt kernel/sched/pelt.h:66 [inline]
RIP: 0010:cfs_rq_clock_pelt kernel/sched/pelt.h:174 [inline]
RIP: 0010:update_load_avg+0x2c0/0x1eb0 kernel/sched/fair.c:4678
Code: 00 41 8b b5 78 0d 00 00 4c 89 ef 85 f6 0f 85 f9 11 00 00 48 83 c7 18 be ff ff ff ff e8 b9 cf 21 09 85 c0 0f 85 fe fd ff ff 90 <0f> 0b 90 e9 f5 fd ff ff 49 8d bc 24 98 00 00 00 48 b8 00 00 00 00
RSP: 0018:ffffc90003e2f3c0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88801caa9800 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8accace0 RDI: ffffffff8b2ee640
RBP: ffff888025591980 R08: 0000000000000000 R09: 000000000000013c
R10: 0000000000000002 R11: 0000000000000002 R12: ffff888025591980
R13: ffff88806b83c740 R14: ffff88806b73d2a0 R15: ffff8880210e5af8
FS:  0000000000000000(0000) GS:ffff88806b700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020afa000 CR3: 000000001bf3a000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 set_next_entity+0x331/0x670 kernel/sched/fair.c:5373
 set_next_task_fair+0x88/0x320 kernel/sched/fair.c:12747
 set_next_task kernel/sched/sched.h:2287 [inline]
 pick_next_task kernel/sched/core.c:6104 [inline]
 __schedule+0x11e4/0x5af0 kernel/sched/core.c:6652
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6865
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1534 [inline]
 zap_pmd_range mm/memory.c:1582 [inline]
 zap_pud_range mm/memory.c:1611 [inline]
 zap_p4d_range mm/memory.c:1632 [inline]
 unmap_page_range+0x13f0/0x2b50 mm/memory.c:1653
 unmap_single_vma+0x194/0x2b0 mm/memory.c:1699
 unmap_vmas+0x229/0x470 mm/memory.c:1743
 exit_mmap+0x1ad/0xa70 mm/mmap.c:3308
 __mmput+0x12a/0x4d0 kernel/fork.c:1349
 mmput+0x62/0x70 kernel/fork.c:1371
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x9ad/0x2ae0 kernel/exit.c:858
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1021
 get_signal+0x23be/0x2790 kernel/signal.c:2904
 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x121/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296
 do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f6ed8c7cae9
Code: Unable to access opcode bytes at 0x7f6ed8c7cabf.
RSP: 002b:00007f6ed99a3178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f6ed8d9bf88 RCX: 00007f6ed8c7cae9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6ed8d9bf88
RBP: 00007f6ed8d9bf80 R08: 00007f6ed99a36c0 R09: 00007f6ed99a36c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6ed8d9bf8c
R13: 000000000000000b R14: 00007ffe2ee63990 R15: 00007ffe2ee63a78
 </TASK>