rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5537/1:b..l P5560/1:b..l (detected by 1, t=10502 jiffies, g=21841, q=1051 ncpus=2) task:modprobe state:R running task stack:23880 pid:5560 ppid:5555 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:717 [inline] RIP: 0010:rcu_is_watching+0x2/0xb0 kernel/rcu/tree.c:720 Code: 44 24 21 02 0f 84 02 ff ff ff e9 6c ff ff ff 48 c7 c7 20 19 33 8d 4c 89 f6 e8 8a ca f0 02 e9 2b ff ff ff e8 50 f3 31 09 41 57 <41> 56 53 65 ff 05 3c 17 8f 7e e8 8f 0b 32 09 89 c3 83 f8 08 73 76 RSP: 0018:ffffc9000a5e76f8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffea000140a4c0 RCX: ffff8880784b5940 RDX: ffff8880784b5940 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff81ecc1bd R09: fffffbfff20e7445 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffffea000140a4c0 R14: ffffffff81ecc18c R15: ffffea000140a4c8 rcu_read_lock include/linux/rcupdate.h:792 [inline] page_ext_get+0x56/0x2a0 mm/page_ext.c:157 __page_table_check_zero+0x139/0x4b0 mm/page_table_check.c:146 page_table_check_free include/linux/page_table_check.h:46 [inline] free_pages_prepare mm/page_alloc.c:1445 [inline] free_pcp_prepare mm/page_alloc.c:1494 [inline] free_unref_page_prepare+0xf73/0x1120 mm/page_alloc.c:3369 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3510 release_pages+0x2836/0x2b40 mm/swap.c:1055 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361 exit_mmap+0x3c3/0x9f0 mm/mmap.c:3239 __mmput+0x115/0x3c0 kernel/fork.c:1199 exit_mm+0x226/0x300 kernel/exit.c:565 do_exit+0x9f6/0x26a0 kernel/exit.c:858 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4cbb7bba90 RSP: 002b:00007ffd591d03f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f4cbb8ac860 RCX: 00007f4cbb7bba90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007f4cbb8ac860 R08: 00007ffd591d0270 R09: 00007ffd591d0350 R10: 00007ffd591d02b0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f4cbb8b0658 R15: 0000000000000001 task:modprobe state:R running task stack:23144 pid:5537 ppid:3722 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 unwind_next_frame+0x1a55/0x2220 arch/x86/kernel/unwind_orc.c:629 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x52/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1444 [inline] free_pcp_prepare mm/page_alloc.c:1494 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3510 release_pages+0x2836/0x2b40 mm/swap.c:1055 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361 exit_mmap+0x3c3/0x9f0 mm/mmap.c:3239 __mmput+0x115/0x3c0 kernel/fork.c:1199 exit_mm+0x226/0x300 kernel/exit.c:565 do_exit+0x9f6/0x26a0 kernel/exit.c:858 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3b0412aa90 RSP: 002b:00007ffd0ca6c968 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f3b0421b860 RCX: 00007f3b0412aa90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007f3b0421b860 R08: 00007ffd0ca6c7e0 R09: 00007ffd0ca6c8c0 R10: 00007ffd0ca6c820 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f3b0421f658 R15: 0000000000000001 rcu: rcu_preempt kthread starved for 10492 jiffies! g21841 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:26080 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 5559 Comm: kworker/u4:22 Not tainted 6.1.105-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1fb0/0x3460 kernel/smp.c:998 Code: 2f 44 89 ee 83 e6 01 31 ff e8 4c 40 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 d7 3c 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc90009b275a0 EFLAGS: 00000293 RAX: ffffffff817f635b RBX: 1ffff11017308595 RCX: ffff8880784b3b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90009b27980 R08: ffffffff817f6324 R09: fffffbfff20e7445 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b9842ca8 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc21d823380 CR3: 000000000d08e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1334 [inline] text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:205 static_key_enable+0x16/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295