rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P939/1:b.el rcu: (detected by 0, t=13182 jiffies, g=13481, q=652 ncpus=2) task:kworker/1:2 state:R running task stack:24744 pid:939 tgid:939 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 1b cd d0 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0000:ffffc90003687860 EFLAGS: 00000206 RAX: 6eb3ec9db389e400 RBX: 0000000000000000 RCX: 6eb3ec9db389e400 RDX: 0000000000000000 RSI: ffffffff8d8f2cda RDI: ffffffff8bbf0460 RBP: ffffffff897245b4 R08: 0000000000000000 R09: ffffffff897245b4 R10: dffffc0000000000 R11: fffffbfff1ef99af R12: 0000000000000002 R13: ffffffff8df3d2e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] gc_worker+0x285/0x1380 net/netfilter/nf_conntrack_core.c:1546 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 13182 jiffies! g13481 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:27112 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 5950 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd44/0x12d0 kernel/smp.c:877 Code: 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 00 eb 38 f3 90 42 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 <74> 1e e8 45 6f 0b 00 eb e4 44 89 e1 80 e1 07 80 c1 03 38 c1 7c e2 RSP: 0018:ffffc900040df480 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 1ffff11017128005 RCX: ffff8880262c5ac0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900040df600 R08: ffff88807a0e3507 R09: 1ffff1100f41c6a0 R10: dffffc0000000000 R11: ffffed100f41c6a1 R12: ffff8880b8940028 R13: dffffc0000000000 R14: ffff8880b883b200 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563901f08a38 CR3: 000000000dd38000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline] flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1471 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 exit_mmap+0x444/0xb40 mm/mmap.c:1293 __mmput+0x118/0x430 kernel/fork.c:1133 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:954 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff82ddc1885 Code: Unable to access opcode bytes at 0x7ff82ddc185b. RSP: 002b:00007ffc10950050 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 0000000000000009 RCX: 00007ff82ddc1885 RDX: 00007ffc10950090 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc109500fc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000006 R13: 0000000000000063 R14: 0000000000021a2c R15: 00007ffc10950150