------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.11.0-syzkaller-10547-g684a64bf32b6 #0 Not tainted
------------------------------------------------------
syz.1.75/5615 is trying to acquire lock:
ffffffff8e813558 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff88801fc3ea98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593
       raw_spin_rq_lock kernel/sched/sched.h:1505 [inline]
       task_rq_lock+0xc6/0x360 kernel/sched/core.c:695
       cgroup_move_task+0x92/0x2d0 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:6692
       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:1105
       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

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
       __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+0xb0/0x1480 kernel/sched/core.c:4154
       up+0x72/0x90 kernel/locking/semaphore.c:191
       __up_console_sem kernel/printk/printk.c:343 [inline]
       __console_unlock+0x123/0x1f0 kernel/printk/printk.c:2844
       __console_flush_and_unlock kernel/printk/printk.c:3241 [inline]
       console_unlock+0x18f/0x3b0 kernel/printk/printk.c:3279
       vga_remove_vgacon+0xbe/0xd0 drivers/pci/vgaarb.c:186
       virtio_gpu_pci_quirk drivers/gpu/drm/virtio/virtgpu_drv.c:61 [inline]
       virtio_gpu_probe+0x347/0x3c0 drivers/gpu/drm/virtio/virtgpu_drv.c:92
       virtio_dev_probe+0x931/0xc80 drivers/virtio/virtio.c:341
       really_probe+0x2b8/0xad0 drivers/base/dd.c:658
       __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800
       driver_probe_device+0x50/0x430 drivers/base/dd.c:830
       __driver_attach+0x45f/0x710 drivers/base/dd.c:1216
       bus_for_each_dev+0x239/0x2b0 drivers/base/bus.c:368
       bus_add_driver+0x346/0x670 drivers/base/bus.c:673
       driver_register+0x23a/0x320 drivers/base/driver.c:246
       do_one_initcall+0x248/0x880 init/main.c:1269
       do_initcall_level+0x157/0x210 init/main.c:1331
       do_initcalls+0x3f/0x80 init/main.c:1347
       kernel_init_freeable+0x435/0x5d0 init/main.c:1580
       kernel_init+0x1d/0x2b0 init/main.c:1469
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 ((console_sem).lock){-...}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3158 [inline]
       check_prevs_add kernel/locking/lockdep.c:3277 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139
       __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:326
       console_trylock kernel/printk/printk.c:2827 [inline]
       console_trylock_spinning kernel/printk/printk.c:1990 [inline]
       vprintk_emit+0x3d7/0xa10 kernel/printk/printk.c:2406
       _printk+0xd5/0x120 kernel/printk/printk.c:2432
       __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
       cpu_max_bits_warn include/linux/cpumask.h:135 [inline]
       cpumask_check include/linux/cpumask.h:142 [inline]
       cpumask_clear_cpu include/linux/cpumask.h:529 [inline]
       __mm_cid_put kernel/sched/sched.h:3542 [inline]
       mm_cid_put+0x18b/0x1f0 kernel/sched/sched.h:3596
       sched_mm_cid_exit_signals+0x221/0x4b0 kernel/sched/core.c:10482
       exit_signals+0x357/0x5c0 kernel/signal.c:3030
       do_exit+0x6b4/0x28e0 kernel/exit.c:896
       do_group_exit+0x207/0x2c0 kernel/exit.c:1088
       get_signal+0x176f/0x1810 kernel/signal.c:2936
       arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
       exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
       do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

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 ***

2 locks held by syz.1.75/5615:
 #0: ffffffff8e96c7d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x6b4/0x28e0 kernel/exit.c:896
 #1: ffff88801fc3ea98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593

stack backtrace:
CPU: 0 UID: 0 PID: 5615 Comm: syz.1.75 Not tainted 6.11.0-syzkaller-10547-g684a64bf32b6 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __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:2203
 check_prev_add kernel/locking/lockdep.c:3158 [inline]
 check_prevs_add kernel/locking/lockdep.c:3277 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139
 __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:326
 console_trylock kernel/printk/printk.c:2827 [inline]
 console_trylock_spinning kernel/printk/printk.c:1990 [inline]
 vprintk_emit+0x3d7/0xa10 kernel/printk/printk.c:2406
 _printk+0xd5/0x120 kernel/printk/printk.c:2432
 __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:cpu_max_bits_warn include/linux/cpumask.h:135 [inline]
RIP: 0010:cpumask_check include/linux/cpumask.h:142 [inline]
RIP: 0010:cpumask_clear_cpu include/linux/cpumask.h:529 [inline]
RIP: 0010:__mm_cid_put kernel/sched/sched.h:3542 [inline]
RIP: 0010:mm_cid_put+0x18b/0x1f0 kernel/sched/sched.h:3596
Code: 89 e8 c1 e8 06 49 8d 3c c6 be 08 00 00 00 e8 3c 88 99 00 89 e8 3e 49 0f b3 06 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 90 <0f> 0b 90 eb d1 90 0f 0b 90 e9 b9 fe ff ff 48 c7 c1 bc 17 1d 90 80
RSP: 0018:ffffc9000b2a78c8 EFLAGS: 00010002
RAX: 000000000000004e RBX: ffff88801fc00000 RCX: ffffffff8164dc6e
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffe8ffffc86ee8
RBP: 000000000000004e R08: ffffe8ffffc86eeb R09: 1ffffd1ffff90ddd
R10: dffffc0000000000 R11: fffff91ffff90dde R12: 0000607fe0086ee0
R13: 00000000ffffffff R14: ffff88805876cb48 R15: dffffc0000000000
 sched_mm_cid_exit_signals+0x221/0x4b0 kernel/sched/core.c:10482
 exit_signals+0x357/0x5c0 kernel/signal.c:3030
 do_exit+0x6b4/0x28e0 kernel/exit.c:896
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 get_signal+0x176f/0x1810 kernel/signal.c:2936
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f742c5b0025
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 c6 57 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 1f 58 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007f742d448f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f742c735f80 RCX: 00007f742c5b0025
RDX: 00007f742d448fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f742c5f0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f742c735f80 R15: 00007ffddb7ad6d8
 </TASK>
WARNING: CPU: 0 PID: 5615 at include/linux/cpumask.h:135 cpu_max_bits_warn include/linux/cpumask.h:135 [inline]
WARNING: CPU: 0 PID: 5615 at include/linux/cpumask.h:135 cpumask_check include/linux/cpumask.h:142 [inline]
WARNING: CPU: 0 PID: 5615 at include/linux/cpumask.h:135 cpumask_clear_cpu include/linux/cpumask.h:529 [inline]
WARNING: CPU: 0 PID: 5615 at include/linux/cpumask.h:135 __mm_cid_put kernel/sched/sched.h:3542 [inline]
WARNING: CPU: 0 PID: 5615 at include/linux/cpumask.h:135 mm_cid_put+0x18b/0x1f0 kernel/sched/sched.h:3596
Modules linked in:
CPU: 0 UID: 0 PID: 5615 Comm: syz.1.75 Not tainted 6.11.0-syzkaller-10547-g684a64bf32b6 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:135 [inline]
RIP: 0010:cpumask_check include/linux/cpumask.h:142 [inline]
RIP: 0010:cpumask_clear_cpu include/linux/cpumask.h:529 [inline]
RIP: 0010:__mm_cid_put kernel/sched/sched.h:3542 [inline]
RIP: 0010:mm_cid_put+0x18b/0x1f0 kernel/sched/sched.h:3596
Code: 89 e8 c1 e8 06 49 8d 3c c6 be 08 00 00 00 e8 3c 88 99 00 89 e8 3e 49 0f b3 06 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 90 <0f> 0b 90 eb d1 90 0f 0b 90 e9 b9 fe ff ff 48 c7 c1 bc 17 1d 90 80
RSP: 0018:ffffc9000b2a78c8 EFLAGS: 00010002
RAX: 000000000000004e RBX: ffff88801fc00000 RCX: ffffffff8164dc6e
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffe8ffffc86ee8
RBP: 000000000000004e R08: ffffe8ffffc86eeb R09: 1ffffd1ffff90ddd
R10: dffffc0000000000 R11: fffff91ffff90dde R12: 0000607fe0086ee0
R13: 00000000ffffffff R14: ffff88805876cb48 R15: dffffc0000000000
FS:  00007f742d4496c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555faae608 CR3: 000000004a1e0000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sched_mm_cid_exit_signals+0x221/0x4b0 kernel/sched/core.c:10482
 exit_signals+0x357/0x5c0 kernel/signal.c:3030
 do_exit+0x6b4/0x28e0 kernel/exit.c:896
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 get_signal+0x176f/0x1810 kernel/signal.c:2936
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f742c5b0025
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 c6 57 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 1f 58 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007f742d448f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f742c735f80 RCX: 00007f742c5b0025
RDX: 00007f742d448fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f742c5f0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f742c735f80 R15: 00007ffddb7ad6d8
 </TASK>