rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=9a7/1/0x4000000000000000 softirq=36532/36533 fqs=5 (t=10502 jiffies g=63941 q=239) rcu: rcu_preempt kthread starved for 10493 jiffies! g63941 f0x0 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:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1211 Comm: kworker/u4:5 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197 Code: 01 f0 4d 89 03 e9 63 fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 <65> 8b 05 e9 02 8b 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc90004f279f0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff8880b9d367c0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff88801cdf9c80 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816ba516 R11: 0000000000000000 R12: ffffed10173a6cf9 R13: 0000000000000001 R14: ffff8880b9d367c8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30626000 CR3: 000000000b68e000 CR4: 00000000003506f0 Call Trace: rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] csd_lock_wait kernel/smp.c:440 [inline] smp_call_function_many_cond+0x450/0xc20 kernel/smp.c:969 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:929 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1114 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:626 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:618 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 1 CPU: 1 PID: 18149 Comm: syz-executor.0 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:div_u64_rem include/linux/math64.h:29 [inline] RIP: 0010:div_u64 include/linux/math64.h:128 [inline] RIP: 0010:pie_calculate_probability+0x27d/0x7c0 net/sched/sch_pie.c:348 Code: 89 c6 4c 89 6c 24 38 e8 91 44 24 fa 47 8d 24 a4 31 d2 4c 89 ff 43 8d 0c 24 48 c1 ed 02 48 b8 ff ff ff ff ff ff ff 00 48 f7 f1 <49> 89 c5 48 89 c6 48 c1 eb 02 49 89 cc e8 31 4a 24 fa 4d 39 ef 73 RSP: 0000:ffffc90000dc0c50 EFLAGS: 00000207 RAX: 0000068db8bac710 RBX: 000000002af31dc4 RCX: 0000000000002710 RDX: 0000000000001eff RSI: ffffffff8752a87f RDI: 0000000000000000 RBP: 000000000112e0be R08: 00000000000f4240 R09: 0000000000000000 R10: ffffffff8752a8c6 R11: 0000000000000000 R12: 0000000000001388 R13: 00004189374bc6a7 R14: 0000000000000004 R15: 0000000000000000 fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 1a 01 23 f8 48 89 ef e8 62 77 23 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 b3 62 16 f8 65 8b 05 2c b2 c8 76 85 c0 74 0a 5b 5d c3 e8 c0 d8 RSP: 0000:ffffc900059c7bd0 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1fa314a RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000001 RBP: ffff888010c7d050 R08: 0000000000000001 R09: ffffffff8fcffa27 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888010c7d000 R13: 0000000000000001 R14: 000000000000000f R15: ffff888010c7d000 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1516 [inline] __pagevec_lru_add+0xd44/0x1be0 mm/swap.c:1055 lru_cache_add+0x5f9/0xa70 mm/swap.c:453 do_anonymous_page mm/memory.c:3808 [inline] handle_pte_fault mm/memory.c:4557 [inline] __handle_mm_fault+0x35e6/0x5320 mm/memory.c:4694 handle_mm_fault+0x1c8/0x790 mm/memory.c:4792 do_user_addr_fault+0x48b/0x11c0 arch/x86/mm/fault.c:1397 handle_page_fault arch/x86/mm/fault.c:1485 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1541 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0033:0x7fbf6fb2062d Code: 84 24 e0 00 00 00 48 89 e1 45 31 c0 48 89 44 24 08 48 8d 44 24 20 c7 04 24 18 00 00 00 c7 44 24 04 30 00 00 00 48 89 44 24 10 7e 9a 00 00 48 8b 4c 24 18 64 48 2b 0c 25 28 00 00 00 75 08 48 RSP: 002b:00007fbf6d0da000 EFLAGS: 00010246 RAX: 00007fbf6d0da020 RBX: 00007fbf6fc67f60 RCX: 00007fbf6d0da000 RDX: 00007fbf6fbbdc52 RSI: 0000000000000080 RDI: 00007fbf6d0da0f0 RBP: 00007fbf6d0da0f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000001798e R12: 0000000000000000 R13: 00007fbf7019bb2f R14: 00007fbf6d0da300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 01 f0 add %esi,%eax 2: 4d 89 03 mov %r8,(%r11) 5: e9 63 fd ff ff jmpq 0xfffffd6d a: b9 ff ff ff ff mov $0xffffffff,%ecx f: ba 08 00 00 00 mov $0x8,%edx 14: 4d 8b 03 mov (%r11),%r8 17: 48 0f bd ca bsr %rdx,%rcx 1b: 49 8b 45 00 mov 0x0(%r13),%rax 1f: 48 63 c9 movslq %ecx,%rcx 22: e9 64 ff ff ff jmpq 0xffffff8b 27: 0f 1f 00 nopl (%rax) * 2a: 65 8b 05 e9 02 8b 7e mov %gs:0x7e8b02e9(%rip),%eax # 0x7e8b031a <-- trapping instruction 31: 89 c1 mov %eax,%ecx 33: 48 8b 34 24 mov (%rsp),%rsi 37: 81 e1 00 01 00 00 and $0x100,%ecx 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b