------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc5-next-20240827-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.53/5515 is trying to acquire lock:
ffffffff8e815278 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff8880b903ead8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:595

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:5825
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:587
       raw_spin_rq_lock kernel/sched/sched.h:1488 [inline]
       task_rq_lock+0xc6/0x360 kernel/sched/core.c:689
       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:6690
       copy_process+0x39e9/0x3d50 kernel/fork.c:2598
       kernel_clone+0x226/0x8f0 kernel/fork.c:2784
       user_mode_thread+0x132/0x1a0 kernel/fork.c:2862
       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:5825
       __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:4150
       up+0x72/0x90 kernel/locking/semaphore.c:191
       __up_console_sem kernel/printk/printk.c:342 [inline]
       __console_unlock kernel/printk/printk.c:2828 [inline]
       console_unlock+0x20d/0x4d0 kernel/printk/printk.c:3155
       vprintk_emit+0x87d/0xa10 kernel/printk/printk.c:2399
       _printk+0xd5/0x120 kernel/printk/printk.c:2424
       report_idle_softirq kernel/time/tick-sched.c:1161 [inline]
       can_stop_idle_tick+0x21d/0x230 kernel/time/tick-sched.c:1178
       tick_nohz_get_sleep_length+0x130/0x1f0 kernel/time/tick-sched.c:1355
       menu_select+0xbf9/0x1e70 drivers/cpuidle/governors/menu.c:279
       cpuidle_idle_call kernel/sched/idle.c:223 [inline]
       do_idle+0x30e/0x5d0 kernel/sched/idle.c:326
       cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424
       start_secondary+0x102/0x110 arch/x86/kernel/smpboot.c:313
       common_startup_64+0x13e/0x147

-> #0 ((console_sem).lock){-...}-{2:2}:
       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+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __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:325
       console_trylock kernel/printk/printk.c:2811 [inline]
       console_trylock_spinning kernel/printk/printk.c:1985 [inline]
       vprintk_emit+0x4b2/0xa10 kernel/printk/printk.c:2398
       _printk+0xd5/0x120 kernel/printk/printk.c:2424
       __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
       dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
       dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
       dequeue_rt_entity kernel/sched/rt.c:1455 [inline]
       dequeue_task_rt+0x12a/0x740 kernel/sched/rt.c:1491
       block_task kernel/sched/core.c:2079 [inline]
       __schedule+0x5d9/0x4b30 kernel/sched/core.c:6627
       __schedule_loop kernel/sched/core.c:6754 [inline]
       schedule+0x14b/0x320 kernel/sched/core.c:6769
       schedule_timeout+0xb0/0x310 kernel/time/timer.c:2559
       unix_wait_for_peer+0x250/0x340 net/unix/af_unix.c:1529
       unix_dgram_sendmsg+0x127f/0x1f80 net/unix/af_unix.c:2131
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:745
       ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2597
       ___sys_sendmsg net/socket.c:2651 [inline]
       __sys_sendmmsg+0x3ab/0x730 net/socket.c:2737
       __do_sys_sendmmsg net/socket.c:2766 [inline]
       __se_sys_sendmmsg net/socket.c:2763 [inline]
       __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
       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

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 ***

1 lock held by syz.4.53/5515:
 #0: ffff8880b903ead8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:595

stack backtrace:
CPU: 0 UID: 0 PID: 5515 Comm: syz.4.53 Not tainted 6.11.0-rc5-next-20240827-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
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: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+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __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:325
 console_trylock kernel/printk/printk.c:2811 [inline]
 console_trylock_spinning kernel/printk/printk.c:1985 [inline]
 vprintk_emit+0x4b2/0xa10 kernel/printk/printk.c:2398
 _printk+0xd5/0x120 kernel/printk/printk.c:2424
 __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:dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
RIP: 0010:dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
Code: 00 00 00 fc ff df e9 0d f5 ff ff 48 c7 c7 e0 e0 7f 8e 48 89 de e8 bd 43 84 03 48 ba 00 00 00 00 00 fc ff df e9 fb fd ff ff 90 <0f> 0b f3 0f 1e fa 8b 74 24 10 f7 de 4c 89 f7 e8 09 92 f8 ff 48 ba
RSP: 0018:ffffc900046e7170 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff816d59ab
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888140ac21e0
RBP: 1ffff11017207d60 R08: ffff888140ac21e7 R09: 1ffff1102815843c
R10: dffffc0000000000 R11: ffffed102815843d R12: ffff8880b903eb00
R13: 1ffff11017207e87 R14: ffff8880b903eac0 R15: ffff8880b903f438
 dequeue_rt_entity kernel/sched/rt.c:1455 [inline]
 dequeue_task_rt+0x12a/0x740 kernel/sched/rt.c:1491
 block_task kernel/sched/core.c:2079 [inline]
 __schedule+0x5d9/0x4b30 kernel/sched/core.c:6627
 __schedule_loop kernel/sched/core.c:6754 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6769
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2559
 unix_wait_for_peer+0x250/0x340 net/unix/af_unix.c:1529
 unix_dgram_sendmsg+0x127f/0x1f80 net/unix/af_unix.c:2131
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmmsg+0x3ab/0x730 net/socket.c:2737
 __do_sys_sendmmsg net/socket.c:2766 [inline]
 __se_sys_sendmmsg net/socket.c:2763 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
 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
RIP: 0033:0x7fd04bd79e79
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd04ca8d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fd04bf15f80 RCX: 00007fd04bd79e79
RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000004
RBP: 00007fd04bde793e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd04bf15f80 R15: 00007ffc7712bf18
 </TASK>
kernel BUG at kernel/sched/rt.c:1035!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 5515 Comm: syz.4.53 Not tainted 6.11.0-rc5-next-20240827-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
RIP: 0010:dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
Code: 00 00 00 fc ff df e9 0d f5 ff ff 48 c7 c7 e0 e0 7f 8e 48 89 de e8 bd 43 84 03 48 ba 00 00 00 00 00 fc ff df e9 fb fd ff ff 90 <0f> 0b f3 0f 1e fa 8b 74 24 10 f7 de 4c 89 f7 e8 09 92 f8 ff 48 ba
RSP: 0018:ffffc900046e7170 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff816d59ab
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888140ac21e0
RBP: 1ffff11017207d60 R08: ffff888140ac21e7 R09: 1ffff1102815843c
R10: dffffc0000000000 R11: ffffed102815843d R12: ffff8880b903eb00
R13: 1ffff11017207e87 R14: ffff8880b903eac0 R15: ffff8880b903f438
FS:  00007fd04ca8d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32906ff8 CR3: 000000007a76a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dequeue_rt_entity kernel/sched/rt.c:1455 [inline]
 dequeue_task_rt+0x12a/0x740 kernel/sched/rt.c:1491
 block_task kernel/sched/core.c:2079 [inline]
 __schedule+0x5d9/0x4b30 kernel/sched/core.c:6627
 __schedule_loop kernel/sched/core.c:6754 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6769
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2559
 unix_wait_for_peer+0x250/0x340 net/unix/af_unix.c:1529
 unix_dgram_sendmsg+0x127f/0x1f80 net/unix/af_unix.c:2131
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmmsg+0x3ab/0x730 net/socket.c:2737
 __do_sys_sendmmsg net/socket.c:2766 [inline]
 __se_sys_sendmmsg net/socket.c:2763 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
 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
RIP: 0033:0x7fd04bd79e79
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd04ca8d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fd04bf15f80 RCX: 00007fd04bd79e79
RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000004
RBP: 00007fd04bde793e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd04bf15f80 R15: 00007ffc7712bf18
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
RIP: 0010:dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
Code: 00 00 00 fc ff df e9 0d f5 ff ff 48 c7 c7 e0 e0 7f 8e 48 89 de e8 bd 43 84 03 48 ba 00 00 00 00 00 fc ff df e9 fb fd ff ff 90 <0f> 0b f3 0f 1e fa 8b 74 24 10 f7 de 4c 89 f7 e8 09 92 f8 ff 48 ba
RSP: 0018:ffffc900046e7170 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff816d59ab
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888140ac21e0
RBP: 1ffff11017207d60 R08: ffff888140ac21e7 R09: 1ffff1102815843c
R10: dffffc0000000000 R11: ffffed102815843d R12: ffff8880b903eb00
R13: 1ffff11017207e87 R14: ffff8880b903eac0 R15: ffff8880b903f438
FS:  00007fd04ca8d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32906ff8 CR3: 000000007a76a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400