loop2: detected capacity change from 0 to 16
erofs: (device loop2): mounted with root inode @ nid 36.
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc4-next-20240822-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.10/5351 is trying to acquire lock:
ffffffff8e815218 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff8880b903ea58 (&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+0x22f/0x4d0 kernel/printk/printk.c:3155
       vprintk_emit+0x87d/0xa10 kernel/printk/printk.c:2399
       _printk+0xd5/0x120 kernel/printk/printk.c:2424
       batadv_check_known_mac_addr+0x2bd/0x410 net/batman-adv/hard-interface.c:528
       batadv_hard_if_event+0x3a5/0x1620 net/batman-adv/hard-interface.c:998
       notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
       call_netdevice_notifiers_extack net/core/dev.c:2032 [inline]
       call_netdevice_notifiers net/core/dev.c:2046 [inline]
       dev_set_mac_address+0x3d9/0x510 net/core/dev.c:9102
       dev_set_mac_address_user+0x31/0x50 net/core/dev.c:9116
       do_setlink+0x8b6/0x41f0 net/core/rtnetlink.c:2855
       __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
       rtnl_newlink+0x180d/0x20a0 net/core/rtnetlink.c:3743
       rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6647
       netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
       netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
       netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
       netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:745
       __sys_sendto+0x3a8/0x500 net/socket.c:2204
       __do_sys_sendto net/socket.c:2216 [inline]
       __se_sys_sendto net/socket.c:2212 [inline]
       __x64_sys_sendto+0xde/0x100 net/socket.c:2212
       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

-> #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
       place_entity+0x463/0x520 kernel/sched/fair.c:5337
       enqueue_entity+0x271/0x1920 kernel/sched/fair.c:5409
       enqueue_task_fair+0x206/0xe30 kernel/sched/fair.c:6985
       enqueue_task+0x1a5/0x300 kernel/sched/core.c:2014
       activate_task kernel/sched/core.c:2056 [inline]
       ttwu_do_activate+0x1d1/0x7e0 kernel/sched/core.c:3665
       ttwu_queue kernel/sched/core.c:3940 [inline]
       try_to_wake_up+0x8bc/0x1480 kernel/sched/core.c:4266
       wake_up_process kernel/sched/core.c:4398 [inline]
       wake_up_q+0xc8/0x120 kernel/sched/core.c:1056
       futex_wake+0x523/0x5c0 kernel/futex/waitwake.c:199
       do_futex+0x392/0x560 kernel/futex/syscalls.c:107
       __do_sys_futex kernel/futex/syscalls.c:179 [inline]
       __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
       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 ***

2 locks held by syz.2.10/5351:
 #0: ffff8880234e0a18 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
 #0: ffff8880234e0a18 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x1480 kernel/sched/core.c:4150
 #1: ffff8880b903ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:595

stack backtrace:
CPU: 0 UID: 0 PID: 5351 Comm: syz.2.10 Not tainted 6.11.0-rc4-next-20240822-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:place_entity+0x463/0x520 kernel/sched/fair.c:5337
Code: 27 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 48 8b 3c 24 4c 89 fe e8 77 14 00 00 48 89 04 24 e9 e0 fd ff ff 90 <0f> 0b 90 41 bd 01 00 00 00 e9 22 ff ff ff 89 d9 80 e1 07 38 c1 0f
RSP: 0018:ffffc90004697870 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000100000
RDX: 0000000000000400 RSI: ffff8880234e0080 RDI: ffff8880234e0100
RBP: dffffc0000000000 R08: ffff88804279c487 R09: 1ffff110084f3890
R10: dffffc0000000000 R11: ffffed10084f3891 R12: 0000000008163bae
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880234e0080
 enqueue_entity+0x271/0x1920 kernel/sched/fair.c:5409
 enqueue_task_fair+0x206/0xe30 kernel/sched/fair.c:6985
 enqueue_task+0x1a5/0x300 kernel/sched/core.c:2014
 activate_task kernel/sched/core.c:2056 [inline]
 ttwu_do_activate+0x1d1/0x7e0 kernel/sched/core.c:3665
 ttwu_queue kernel/sched/core.c:3940 [inline]
 try_to_wake_up+0x8bc/0x1480 kernel/sched/core.c:4266
 wake_up_process kernel/sched/core.c:4398 [inline]
 wake_up_q+0xc8/0x120 kernel/sched/core.c:1056
 futex_wake+0x523/0x5c0 kernel/futex/waitwake.c:199
 do_futex+0x392/0x560 kernel/futex/syscalls.c:107
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
 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: 0033:0x7fe6d3179e79
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:00007fe6d3e970e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fe6d3316060 RCX: 00007fe6d3179e79
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe6d3316064
RBP: 00007fe6d3316058 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe6d3316064
R13: 0000000000000000 R14: 00007ffec791ea90 R15: 00007ffec791eb78
 </TASK>
WARNING: CPU: 0 PID: 5351 at kernel/sched/fair.c:5337 place_entity+0x463/0x520 kernel/sched/fair.c:5337
Modules linked in:
CPU: 0 UID: 0 PID: 5351 Comm: syz.2.10 Not tainted 6.11.0-rc4-next-20240822-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:place_entity+0x463/0x520 kernel/sched/fair.c:5337
Code: 27 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 48 8b 3c 24 4c 89 fe e8 77 14 00 00 48 89 04 24 e9 e0 fd ff ff 90 <0f> 0b 90 41 bd 01 00 00 00 e9 22 ff ff ff 89 d9 80 e1 07 38 c1 0f
RSP: 0018:ffffc90004697870 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000100000
RDX: 0000000000000400 RSI: ffff8880234e0080 RDI: ffff8880234e0100
RBP: dffffc0000000000 R08: ffff88804279c487 R09: 1ffff110084f3890
R10: dffffc0000000000 R11: ffffed10084f3891 R12: 0000000008163bae
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880234e0080
FS:  00007fe6d3e976c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 0000000029b2a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 enqueue_entity+0x271/0x1920 kernel/sched/fair.c:5409
 enqueue_task_fair+0x206/0xe30 kernel/sched/fair.c:6985
 enqueue_task+0x1a5/0x300 kernel/sched/core.c:2014
 activate_task kernel/sched/core.c:2056 [inline]
 ttwu_do_activate+0x1d1/0x7e0 kernel/sched/core.c:3665
 ttwu_queue kernel/sched/core.c:3940 [inline]
 try_to_wake_up+0x8bc/0x1480 kernel/sched/core.c:4266
 wake_up_process kernel/sched/core.c:4398 [inline]
 wake_up_q+0xc8/0x120 kernel/sched/core.c:1056
 futex_wake+0x523/0x5c0 kernel/futex/waitwake.c:199
 do_futex+0x392/0x560 kernel/futex/syscalls.c:107
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
 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: 0033:0x7fe6d3179e79
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:00007fe6d3e970e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fe6d3316060 RCX: 00007fe6d3179e79
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe6d3316064
RBP: 00007fe6d3316058 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe6d3316064
R13: 0000000000000000 R14: 00007ffec791ea90 R15: 00007ffec791eb78
 </TASK>