rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=865/1/0x4000000000000000 softirq=15563/15564 fqs=0 (detected by 0, t=10503 jiffies, g=21545, q=48 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5524 Comm: syz-executor.2 Not tainted 5.19.0-rc8-syzkaller-00003-g5de64d44968e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 RIP: 0010:lock_acquire kernel/locking/lockdep.c:5665 [inline] RIP: 0010:lock_acquire+0x189/0x570 kernel/locking/lockdep.c:5630 Code: 8f 44 24 08 fa 48 c7 c7 60 72 cc 89 e8 10 dc 19 08 41 89 e8 44 89 e1 44 89 ea 65 ff 05 18 f1 a4 7e 48 81 64 24 08 00 02 00 00 <44> 89 fe 6a 00 4c 89 f7 6a 00 ff b4 24 f8 00 00 00 ff 74 24 18 41 RSP: 0018:ffffc900003f8ce0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff9200007f19e RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000010001 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8dbb1697 R10: fffffbfff1b762d2 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bd846e0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ee21000 CR3: 000000000ba8e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:269 [inline] rcu_read_lock include/linux/rcupdate.h:695 [inline] advance_sched+0x4a5/0x9a0 net/sched/sch_taprio.c:768 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:207 [inline] RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline] RIP: 0010:folio_test_slab include/linux/page-flags.h:506 [inline] RIP: 0010:__folio_memcg include/linux/memcontrol.h:403 [inline] RIP: 0010:folio_memcg include/linux/memcontrol.h:455 [inline] RIP: 0010:folio_memcg_unlock mm/memcontrol.c:2105 [inline] RIP: 0010:unlock_page_memcg+0x6c/0x2c0 mm/memcontrol.c:2110 Code: e8 f9 af fe ff be 08 00 00 00 48 89 c3 48 89 c7 e8 49 bf f8 ff 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 15 02 00 00 48 8b 03 f6 c4 02 0f 85 a0 01 00 00 41 f6 c4 01 RSP: 0018:ffffc900050076f0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffea0001caa480 RCX: ffffffff81cd1e57 RDX: 1ffffd4000395490 RSI: 0000000000000008 RDI: ffffea0001caa480 RBP: ffffea0001caa480 R08: 0000000000000000 R09: ffffea0001caa487 R10: fffff94000395490 R11: 0000000000000001 R12: 0000000000000000 R13: ffffea0001caa488 R14: 0000000000000000 R15: 0000000000000000 page_remove_rmap+0x318/0x1510 mm/rmap.c:1465 zap_pte_range mm/memory.c:1446 [inline] zap_pmd_range mm/memory.c:1567 [inline] zap_pud_range mm/memory.c:1596 [inline] zap_p4d_range mm/memory.c:1617 [inline] unmap_page_range+0x115f/0x3e20 mm/memory.c:1638 unmap_single_vma+0x196/0x360 mm/memory.c:1686 unmap_vmas+0x18c/0x310 mm/memory.c:1723 exit_mmap+0x1c4/0x4a0 mm/mmap.c:3162 __mmput+0x122/0x4b0 kernel/fork.c:1187 mmput+0x56/0x60 kernel/fork.c:1208 exit_mm kernel/exit.c:510 [inline] do_exit+0x9f1/0x29d0 kernel/exit.c:782 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x2542/0x2600 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2d5a889209 Code: Unable to access opcode bytes at RIP 0x7f2d5a8891df. RSP: 002b:00007f2d5ba8f218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f2d5a99bf68 RCX: 00007f2d5a889209 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f2d5a99bf6c RBP: 00007f2d5a99bf60 R08: 00007ffd0532d080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2d5a99bf6c R13: 00007ffd052214cf R14: 00007f2d5ba8f300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10503 jiffies! g21545 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:28864 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5146 [inline] __schedule+0xa00/0x4b50 kernel/sched/core.c:6458 schedule+0xd2/0x1f0 kernel/sched/core.c:6530 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1999 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2187 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 41 Comm: kworker/u4:2 Not tainted 5.19.0-rc8-syzkaller-00003-g5de64d44968e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: events_unbound toggle_allocation_gate 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:111 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:518 print_other_cpu_stall kernel/rcu/tree_stall.h:623 [inline] check_cpu_stall kernel/rcu/tree_stall.h:769 [inline] rcu_pending kernel/rcu/tree.c:3977 [inline] rcu_sched_clock_irq+0x2311/0x2370 kernel/rcu/tree.c:2675 update_process_times+0x11a/0x1a0 kernel/time/timer.c:1839 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1480 __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:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:csd_lock_wait kernel/smp.c:414 [inline] RIP: 0010:smp_call_function_many_cond+0x499/0x1110 kernel/smp.c:988 Code: 01 89 ee e8 49 98 0a 00 85 ed 74 47 48 8b 04 24 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 fc 83 c5 03 e8 e9 9b 0a 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 21 0a 00 00 8b 43 08 31 RSP: 0018:ffffc90000d2f950 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9b3f740 RCX: 0000000000000000 RDX: ffff888012986080 RSI: ffffffff816f0127 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffed1017367ee9 R13: 0000000000000001 R14: 0000000000000001 R15: dffffc0000000000 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1154 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1302 [inline] text_poke_bp_batch+0x233/0x6c0 arch/x86/kernel/alternative.c:1490 text_poke_flush arch/x86/kernel/alternative.c:1660 [inline] text_poke_flush arch/x86/kernel/alternative.c:1657 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1667 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 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:811 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:803 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 vkms_vblank_simulate: vblank timer overrun