rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8858/1:b..l P9/1:b..l rcu: (detected by 1, t=10502 jiffies, g=28853, q=148 ncpus=2) task:kworker/0:0 state:R running task stack:21080 pid:9 tgid:9 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:seqcount_lockdep_reader_access+0x17e/0x1c0 include/linux/seqlock.h:75 Code: f8 4d 85 e4 75 16 e8 91 83 4e f8 eb 15 e8 8a 83 4e f8 e8 25 91 d4 01 4d 85 e4 74 ea e8 7b 83 4e f8 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00 RSP: 0018:ffffc900000e7840 EFLAGS: 00000293 RAX: ffffffff897180f5 RBX: 0000000000000000 RCX: ffff88801c6b0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900000e78f0 R08: ffffffff8f7cd477 R09: 1ffffffff1ef9a8e R10: dffffc0000000000 R11: fffffbfff1ef9a8f R12: 0000000000000200 R13: ffff88801c2d7718 R14: 1ffff9200001cf08 R15: dffffc0000000000 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline] gc_worker+0x308/0x1380 net/netfilter/nf_conntrack_core.c:1548 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 task:syz.3.777 state:R running task stack:27112 pid:8858 tgid:8858 ppid:5833 task_flags:0x40004c flags:0x00080000 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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pmdp_get include/linux/pgtable.h:347 [inline] RIP: 0010:pmdp_get_lockless include/linux/pgtable.h:635 [inline] RIP: 0010:___pte_offset_map+0xe6/0x250 mm/pgtable-generic.c:288 Code: 76 8b e8 8d a2 8b ff 49 bd 00 00 00 00 00 fc ff df 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 cd de 13 00 4d 8b 26 <4c> 89 24 24 4d 85 ff 74 20 e8 9c 29 ae ff 4c 89 f8 48 c1 e8 03 42 RSP: 0018:ffffc9000ac0f528 EFLAGS: 00000246 RAX: 1ffff1100f19fe61 RBX: 000000110c2f0000 RCX: ffff888030319e40 RDX: 0000000000000000 RSI: ffffffff8bbf05c0 RDI: ffffffff8bbf0580 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8211da09 R10: dffffc0000000000 R11: fffff52001581efe R12: 00000000269dc067 R13: dffffc0000000000 R14: ffff888078cff308 R15: ffffc9000ac0f598 __pte_offset_map include/linux/mm.h:3118 [inline] __pte_offset_map_lock+0x46/0x210 mm/pgtable-generic.c:397 pte_offset_map_lock include/linux/mm.h:3133 [inline] zap_pte_range mm/memory.c:1840 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x3b97/0x4370 mm/memory.c:2017 unmap_single_vma mm/memory.c:2060 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2104 exit_mmap+0x240/0xb40 mm/mmap.c:1280 __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 __do_sys_exit_group kernel/exit.c:1118 [inline] __se_sys_exit_group kernel/exit.c:1116 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d2338efc9 RSP: 002b:00007ffdcc8dad98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0d2338efc9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdcc8dadfc R08: 00000002cc8dae8f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000007a R13: 00000000000927c0 R14: 0000000000060afe R15: 00007ffdcc8dae50 rcu: rcu_preempt kthread starved for 10493 jiffies! g28853 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:27224 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 5e 33 ca f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 21 22 00 f3 0f 1e fa fb f4 33 33 ca f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: 151318fa089d6f00 RBX: ffffffff81967be7 RCX: 151318fa089d6f00 RDX: 0000000000000001 RSI: ffffffff8d70bf1d RDI: ffffffff8bbf05e0 RBP: ffffffff8dc07ea8 R08: ffff8880b8832fdb R09: 1ffff110171065fb R10: dffffc0000000000 R11: ffffed10171065fc R12: ffffffff8f7cd470 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a40 FS: 0000000000000000(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faf741e39d5 CR3: 0000000059def000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147