rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17880/1:b..l rcu: (detected by 1, t=10504 jiffies, g=121301, q=324 ncpus=2) task:modprobe state:R running task stack:24104 pid:17880 tgid:17880 ppid:1339 task_flags:0x40000c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x89/0x3e0 kernel/locking/lockdep.c:5884 Code: 45 03 0e 00 0f 84 44 02 00 00 65 8b 05 90 ec ff 10 85 c0 0f 85 35 02 00 00 65 4c 8b 3c 25 08 f0 9d 92 41 83 bf ec 0a 00 00 00 <0f> 85 1e 02 00 00 49 81 3e 40 b3 61 93 0f 84 11 02 00 00 48 c7 44 RSP: 0018:ffffc90003dff150 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff903c5d01 RCX: 0882151daa463800 RDX: ffffc90003dff201 RSI: ffffffff8be2ea40 RDI: ffffffff8be2ea00 RBP: dffffc0000000000 R08: ffffc90003dffc18 R09: 0000000000000000 R10: ffffc90003dff2d8 R11: fffff520007bfe5d R12: ffffc90003dffc28 R13: ffffffff81729af5 R14: ffffffff8e13ee20 R15: ffff888024ab9e00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763 folios_put_refs+0x559/0x640 mm/swap.c:992 free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:264 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 exit_mmap+0x44c/0xb50 mm/mmap.c:1297 __mmput+0x118/0x420 kernel/fork.c:1120 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x22e0 kernel/exit.c:952 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 __do_sys_exit_group kernel/exit.c:1116 [inline] __se_sys_exit_group kernel/exit.c:1114 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7c634eb6c5 RSP: 002b:00007ffc6d7f6dc8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f7c635ecfe8 RCX: 00007f7c634eb6c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001 RBP: 0000000000000001 R08: 00007ffc6d7f6d58 R09: 0000000000000000 R10: 00007ffc6d7f6bf0 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f7c635eb680 R15: 00007f7c635ed000 rcu: rcu_preempt kthread starved for 10504 jiffies! g121301 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:26632 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2060 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2262 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 1168 Comm: kworker/u8:5 Not tainted 6.16.0-rc1-next-20250613-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 e0 7d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8b 79 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 70 79 0b RSP: 0018:ffffc90003fbf6a0 EFLAGS: 00000293 RAX: ffffffff81b4ee20 RBX: ffff8880b873cb40 RCX: ffff8880270d8000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003fbf800 R08: ffffffff8fa157f7 R09: 1ffffffff1f42afe R10: dffffc0000000000 R11: fffffbfff1f42aff R12: 1ffff110170c86b5 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b86435a8 FS: 0000000000000000(0000) GS:ffff888125d41000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c37f585 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline] smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3235 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3318 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3399 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245