rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=4793, q=23) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294967025-4294956523), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g4793 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:27000 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 3544 Comm: syz-executor371 Not tainted 5.15.158-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_is_held_type+0xa/0x180 kernel/locking/lockdep.c:5651 Code: 48 c7 c6 60 28 8b 8a e8 24 35 2e f7 0f 0b eb bf e8 ab fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 55 41 57 41 56 41 55 41 54 53 <48> 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 bd ff ff ff RSP: 0018:ffffc90002db7ac8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8880786ed940 RCX: ffff8880786ed940 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8c91fb40 RBP: ffffc90002db7c10 R08: ffffffff81b9caac R09: fffffbfff186bc66 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920005b6f68 lock_is_held include/linux/lockdep.h:287 [inline] ___might_sleep+0xa2/0x6a0 kernel/sched/core.c:9592 __might_fault+0x6b/0x110 mm/memory.c:5325 _copy_to_user+0x28/0x130 lib/usercopy.c:35 copy_to_user include/linux/uaccess.h:200 [inline] copy_siginfo_to_user+0x20/0x80 kernel/signal.c:3356 __setup_rt_frame arch/x86/kernel/signal.c:490 [inline] setup_rt_frame arch/x86/kernel/signal.c:780 [inline] handle_signal arch/x86/kernel/signal.c:824 [inline] arch_do_signal_or_restart+0xb0a/0x1890 arch/x86/kernel/signal.c:869 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f1214b6fe79 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd9394fd18 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f1214b6fe79 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00005555560ce370 R13: 0000000000000003 R14: 00007ffd9394fd90 R15: 00007ffd9394fd80