syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=66fc/1/0x4000000000000000 softirq=39095/39095 fqs=0
rcu: 	(detected by 1, t=10503 jiffies, g=28965, q=67 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9302 Comm: syz.0.916 Not tainted 6.15.0-rc4-syzkaller-00052-g4f79eaa2ceac #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:hlock_class+0x13/0x70 kernel/locking/lockdep.c:233
Code: 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f b7 47 20 66 25 ff 1f 0f b7 c0 48 0f a3 05 4d eb 12 14 <73> 15 48 8d 04 80 48 8d 04 80 48 8d 04 c5 60 8f aa 95 c3 cc cc cc
RSP: 0018:ffffc90000007be8 EFLAGS: 00000047
RAX: 0000000000000000 RBX: ffff88803073d488 RCX: 00000000c032add5
RDX: 0000000000000000 RSI: ffff88803073d488 RDI: ffff88803073d488
RBP: ffff88803073d370 R08: 0000000000080000 R09: 0000000000000001
R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000002 R14: ffff88803073c880 R15: 0000000000000000
FS:  00007fbb6a95d6c0(0000) GS:ffff8881249e2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3b4fcb CR3: 00000000366ad000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __lock_acquire+0x5ca/0x1ba0 kernel/locking/lockdep.c:5232
 lock_acquire kernel/locking/lockdep.c:5866 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x135/0x3a0 lib/debugobjects.c:873
 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
 debug_deactivate kernel/time/hrtimer.c:490 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1729 [inline]
 __hrtimer_run_queues+0x46f/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 e6 ee 28 f6 48 89 df e8 8e 42 29 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 e5 ae 19 f6 65 8b 05 1e c4 34 08 85 c0 74 16 5b
RSP: 0018:ffffc9000be078a8 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff88801b492f08 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8dbe0901 RDI: ffffffff8bf47e20
RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9084fd17 R11: 0000000000000000 R12: 0000000000000283
R13: ffff88801b492f08 R14: 0000000000000000 R15: 1ffff920017c0f44
 kthread_queue_work+0xa8/0x170 kernel/kthread.c:1195
 synchronize_rcu_expedited_queue_work kernel/rcu/tree_exp.h:498 [inline]
 synchronize_rcu_expedited+0x2f4/0x460 kernel/rcu/tree_exp.h:1008
 led_trigger_set+0x554/0xc50 drivers/leds/led-triggers.c:202
 led_match_default_trigger drivers/leds/led-triggers.c:269 [inline]
 led_match_default_trigger drivers/leds/led-triggers.c:263 [inline]
 led_trigger_set_default drivers/leds/led-triggers.c:287 [inline]
 led_trigger_set_default+0x1bd/0x2a0 drivers/leds/led-triggers.c:276
 led_classdev_register_ext+0x7b8/0xa10 drivers/leds/led-class.c:566
 led_classdev_register include/linux/leds.h:274 [inline]
 input_leds_connect+0x552/0x8e0 drivers/input/input-leds.c:145
 input_attach_handler.isra.0+0x181/0x260 drivers/input/input.c:993
 input_register_device+0xa84/0x1130 drivers/input/input.c:2412
 uinput_create_device drivers/input/misc/uinput.c:365 [inline]
 uinput_ioctl_handler.isra.0+0x1357/0x1df0 drivers/input/misc/uinput.c:918
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl fs/ioctl.c:892 [inline]
 __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb69b8e969
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:00007fbb6a95d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbb69db5fa0 RCX: 00007fbb69b8e969
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 000000000000000a
RBP: 00007fbb69c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbb69db5fa0 R15: 00007ffe0bd403e8
 </TASK>
rcu: rcu_preempt kthread starved for 10503 jiffies! g28965 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:26760 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6860
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.15.0-rc4-syzkaller-00052-g4f79eaa2ceac #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81
Code: 65 62 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 6a 1d 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6
RAX: 0000000002847db9 RBX: 0000000000000001 RCX: ffffffff8b6c8419
RDX: 0000000000000000 RSI: ffffffff8dbe0901 RDI: ffffffff8bf47e20
RBP: ffffed1003b5a488 R08: 0000000000000001 R09: ffffed10170a65bd
R10: ffff8880b8532deb R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801dad2440 R14: ffffffff9084fd10 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124ae2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7ee3bb3f98 CR3: 0000000021bce000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>