syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4171/1:b..l
	(detected by 1, t=10502 jiffies, g=9745, q=264 ncpus=2)
task:syz.3.171       state:R  running task     stack:24208 pid:4171  ppid:3551   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:arch_stack_walk+0x114/0x140 arch/x86/kernel/stacktrace.c:24
Code: ff 48 89 df e8 7d fd 08 00 48 85 c0 74 1e 4c 89 f7 48 89 c6 41 ff d5 84 c0 74 11 48 89 df e8 83 fe 08 00 83 bd 70 ff ff ff 00 <75> d5 65 48 8b 04 25 28 00 00 00 48 3b 45 d0 75 0f 48 83 c4 68 5b
RSP: 0018:ffffc9000ad8f340 EFLAGS: 00000202
RAX: 0000000080000001 RBX: ffffc9000ad8f340 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffc9000ad88000 RDI: 0000000000000001
RBP: ffffc9000ad8f3d0 R08: ffffc9000ad8ff48 R09: ffffc9000ad8f390
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801f5c1dc0
R13: ffffffff817850e0 R14: ffffc9000ad8f420 R15: 0000000000000000
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 save_stack+0xf6/0x1e0 mm/page_owner.c:127
 __reset_page_owner+0x52/0x1a0 mm/page_owner.c:148
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1444 [inline]
 free_pcp_prepare mm/page_alloc.c:1494 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3362
 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3457
 __vunmap+0x834/0x9a0 mm/vmalloc.c:2717
 kcov_put kernel/kcov.c:428 [inline]
 kcov_close+0x27/0x50 kernel/kcov.c:524
 __fput+0x3f6/0x8d0 fs/file_table.c:320
 task_work_run+0x246/0x300 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa73/0x26a0 kernel/exit.c:871
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 get_signal+0x16f7/0x17d0 kernel/signal.c:2862
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1e60575bd9
RSP: 002b:00007ffeec292e18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f1e60705a60 RCX: 00007f1e60575bd9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f1e60705a60 R08: 00007f1e5fbff000 R09: 00000008ec29313f
R10: 00000000005f3f6c R11: 0000000000000246 R12: 000000000001641c
R13: 0000000000000032 R14: 00007f1e60705a60 R15: 00007f1e60704038
 </TASK>
rcu: rcu_preempt kthread starved for 9413 jiffies! g9745 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:25528 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline]
RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572
Code: 27 f5 f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 e4 e5 fb f6 0f 1f 44 00 00 e8 3a 23 f5 f6 0f 00 2d 83 f4 b1 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 5b a7 4c f7
RSP: 0018:ffffc90000177b80 EFLAGS: 000002d3
RAX: ffffffff8a957316 RBX: 0000000000000000 RCX: ffff888012739dc0
RDX: 0000000000000000 RSI: ffffffff8aec0240 RDI: ffffffff8b3d47e0
RBP: ffffc90000177c10 R08: ffffffff8a9572f8 R09: ffffed10024e73b9
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200002ef70
R13: ffff888143aff004 R14: ffffc90000177ba0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3c8e675580 CR3: 0000000018f04000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:709
 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239
 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x3ce/0x680 kernel/sched/idle.c:303
 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401
 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>