rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=892c/1/0x4000000000000000 softirq=31575/31609 fqs=12 rcu: (detected by 1, t=10506 jiffies, g=25697, q=128 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9158 Comm: syz.1.1155 Not tainted 6.13.0-rc1-syzkaller-00005-gceb8bf2ceaa7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x41/0xc0 kernel/rcu/tree.c:737 Code: 03 00 83 f8 07 89 c5 0f 87 82 00 00 00 48 8d 3c ed e0 2b a7 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <75> 5c 48 03 1c ed e0 2b a7 8d 48 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffffc90000007d38 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000037f68 RCX: ffffffff8176abc9 RDX: 1ffffffff1b4e57c RSI: ffffffff8bd1b3e0 RDI: ffffffff8da72be0 RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff20be082 R10: ffffffff905f0417 R11: 0000000000000001 R12: ffff8880b862ca18 R13: ffff8880b862cb00 R14: ffff8880b862ca00 R15: ffffffff8941c310 FS: 0000555567913500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f106ff8 CR3: 0000000059866000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4e2/0x6f0 kernel/locking/lockdep.c:5860 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1735 [inline] __hrtimer_run_queues+0x53d/0xae0 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 06 64 4a f6 48 89 df e8 4e e3 4a f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 d5 d7 3b f6 65 8b 05 c6 91 d7 74 85 c0 74 16 5b RSP: 0018:ffffc9000466fb88 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff8880325a5280 RCX: 1ffffffff20bd839 RDX: 0000000000000000 RSI: ffffffff8b6cd840 RDI: ffffffff8bd1b460 RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff905f0417 R11: 0000000000000002 R12: ffff8880325a4894 R13: ffff8880325a5280 R14: ffff8880325a4880 R15: ffff8880b863ebc0 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0x949/0x1490 kernel/sched/core.c:4205 wake_up_process kernel/sched/core.c:4454 [inline] wake_up_q+0x91/0x140 kernel/sched/core.c:1066 futex_wake+0x43e/0x4e0 kernel/futex/waitwake.c:199 do_futex+0x1e5/0x350 kernel/futex/syscalls.c:107 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex kernel/futex/syscalls.c:160 [inline] __x64_sys_futex+0x1e1/0x4c0 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f710117ff19 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:00007fff72487e28 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f7101345fa8 RCX: 00007f710117ff19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f7101345fa8 RBP: 00007f7101345fac R08: 0000000000000000 R09: 00007fff7248810f R10: 00007f7101345fa0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7101345fa0 R14: 0000000000000003 R15: 0000000000000c2b rcu: rcu_preempt kthread starved for 10445 jiffies! g25697 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:28336 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: 1050 Comm: kworker/u8:5 Not tainted 6.13.0-rc1-syzkaller-00005-gceb8bf2ceaa7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: iou_exit io_ring_exit_work RIP: 0010:__sanitizer_cov_trace_pc+0x66/0x70 kernel/kcov.c:235 Code: 82 f8 15 00 00 83 f8 02 75 20 48 8b 8a 00 16 00 00 8b 92 fc 15 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90003fff880 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b86469c0 RCX: ffffffff818df8bc RDX: ffff888027642440 RSI: ffffffff818df896 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170c8d39 R13: 0000000000000001 R14: ffff8880b86469c8 R15: ffff8880b873fe40 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020088030 CR3: 000000000df7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 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:340 [inline] smp_call_function_many_cond+0x456/0x1300 kernel/smp.c:884 on_each_cpu_cond_mask+0x40/0x90 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+0x22b/0x760 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_flush arch/x86/kernel/alternative.c:2512 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 __static_key_slow_dec_cpuslocked.part.0+0xc0/0xf0 kernel/jump_label.c:315 __static_key_slow_dec_cpuslocked kernel/jump_label.c:297 [inline] __static_key_slow_dec kernel/jump_label.c:321 [inline] static_key_slow_dec+0x7c/0xc0 kernel/jump_label.c:336 io_ring_ctx_free io_uring/io_uring.c:2753 [inline] io_ring_exit_work+0xfa3/0x1b20 io_uring/io_uring.c:2964 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244