rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=312c/1/0x4000000000000000 softirq=21664/21668 fqs=2 rcu: (detected by 1, t=10505 jiffies, g=16521, q=931 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7903 Comm: syz.4.532 Not tainted 6.12.0-rc6-next-20241107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] RIP: 0010:do_raw_spin_lock+0x8d/0x370 kernel/locking/spinlock_debug.c:115 Code: f1 04 f3 f3 f3 48 89 f1 48 89 74 24 38 48 89 04 16 48 8d 5f 04 48 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 f6 01 00 00 8b 03 <3d> ad 4e ad de 0f 85 62 01 00 00 4d 8d 6c 24 10 4c 89 e8 48 c1 e8 RSP: 0018:ffffc90000007ac0 EFLAGS: 00000046 RAX: 00000000dead4ead RBX: ffffffff9a5c1a54 RCX: 1ffff92000000f60 RDX: dffffc0000000000 RSI: 1ffff92000000f60 RDI: ffffffff9a5c1a50 RBP: ffffc90000007b90 R08: ffffffff901c70f7 R09: 1ffffffff2038e1e R10: dffffc0000000000 R11: fffffbfff2038e1f R12: ffffffff9a5c1a50 R13: 1ffff92000000f74 R14: ffffffff9a5c1a50 R15: dffffc0000000000 FS: 00007f1a7d0976c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c329b05 CR3: 000000002436c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 00000000000000e0 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x158/0x390 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:428 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:484 __run_hrtimer kernel/time/hrtimer.c:1659 [inline] __hrtimer_run_queues+0x305/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:local_lock_acquire include/linux/local_lock_internal.h:30 [inline] RIP: 0010:mlock_new_folio+0x1c6/0xc40 mm/mlock.c:272 Code: ee e8 be a1 ad ff 85 ed 74 07 e8 75 9d ad ff eb 33 48 8d 6b 28 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 ef e8 b0 13 18 00 48 83 7d 00 00 0f 85 b5 04 00 00 e8 RSP: 0018:ffffc900176ef300 EFLAGS: 00000246 RAX: 1ffff110170c710d RBX: ffff8880b8638840 RCX: dffffc0000000000 RDX: ffff88802c423c00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880b8638868 R08: ffffffff81f1c9a2 R09: 1ffffffff2038e1e R10: dffffc0000000000 R11: fffffbfff2038e1f R12: 0000000000000001 R13: ffffea0001dc4cc0 R14: 0000000000000001 R15: ffff88805c8fd6c8 do_anonymous_page mm/memory.c:4863 [inline] do_pte_missing mm/memory.c:3984 [inline] handle_pte_fault+0x4a1e/0x66b0 mm/memory.c:5808 __handle_mm_fault mm/memory.c:5951 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6119 faultin_page mm/gup.c:1187 [inline] __get_user_pages+0x1c82/0x49e0 mm/gup.c:1485 populate_vma_page_range+0x264/0x330 mm/gup.c:1923 __mm_populate+0x27a/0x460 mm/gup.c:2026 do_mlock+0x6cc/0x850 mm/mlock.c:653 __do_sys_mlock mm/mlock.c:661 [inline] __se_sys_mlock mm/mlock.c:659 [inline] __x64_sys_mlock+0x60/0x70 mm/mlock.c:659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a7c37e719 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1a7d097038 EFLAGS: 00000246 ORIG_RAX: 0000000000000095 RAX: ffffffffffffffda RBX: 00007f1a7c535f80 RCX: 00007f1a7c37e719 RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000000020000000 RBP: 00007f1a7c3f139e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1a7c535f80 R15: 00007ffd362ec228 rcu: rcu_preempt kthread starved for 10496 jiffies! g16521 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:26264 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5327 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6707 __schedule_loop kernel/sched/core.c:6784 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6799 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted 6.12.0-rc6-next-20241107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2ca0 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 66 f6 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 11 f2 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 f5 f1 RSP: 0018:ffffc90000ab76e0 EFLAGS: 00000293 RAX: ffffffff8193752b RBX: 1ffff110170c8c59 RCX: ffff88801dec3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000ab78e0 R08: ffffffff819374fa R09: 1ffffffff2038e1e R10: dffffc0000000000 R11: fffffbfff2038e1f R12: dffffc0000000000 R13: ffff8880b86462c8 R14: ffff8880b873f980 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0c7d0746c0 CR3: 000000000e738000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 00000000000000e0 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244