rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=13529, q=36) rcu: All QSes seen, last rcu_preempt kthread activity 10429 (4294964589-4294954160), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10430 jiffies! g13529 f0x2 RCU_GP_CLEANUP(7) ->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:26168 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6549 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6574 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202 rcu_gp_cleanup+0x130/0xba0 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xb2/0x360 kernel/rcu/tree.c:2149 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 4900 Comm: syz.0.295 Not tainted 5.15.166-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 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:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 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_release+0x62d/0x9a0 kernel/locking/lockdep.c:5647 Code: 3c 3b 00 74 08 4c 89 f7 e8 c0 49 67 00 f6 84 24 91 00 00 00 02 75 6f 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc90003257be0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200064af8e RCX: ffffc90003257c03 RDX: 0000000000000000 RSI: ffffffff8a8b3cc0 RDI: ffffffff8ad90100 RBP: ffffc90003257d20 R08: dffffc0000000000 R09: fffffbfff1bd2b66 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200064af88 R13: 0000000000000246 R14: ffffc90003257c70 R15: dffffc0000000000 _copy_from_user+0x28/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:192 [inline] restore_altstack+0x9a/0x400 kernel/signal.c:4249 __do_sys_rt_sigreturn+0x19d/0x250 arch/x86/kernel/signal.c:677 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4a868c3390 Code: 10 83 e0 01 83 e2 01 88 15 5a 63 e2 00 88 05 57 63 e2 00 c3 50 48 8d 35 be fc 1a 00 48 8d 3d c4 fc 1a 00 31 c0 e8 a0 f9 ff ff <53> 89 fb 48 83 ec 10 64 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 RSP: 002b:00007f4a84e369b8 EFLAGS: 00000283 RAX: 0000000000000000 RBX: 00007f4a84e37024 RCX: 0000000000000000 RDX: 00007f4a84e369c0 RSI: 00007f4a84e36af0 RDI: 000000000000000b RBP: 0000000000000006 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000000000 R13: 00007f4a84e36fc0 R14: 00007f4a86bba130 R15: 0000000000000000