rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20156/1:b..l rcu: (detected by 0, t=10502 jiffies, g=234841, q=199 ncpus=2) task:modprobe state:R running task stack:24848 pid:20156 ppid:8531 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x196c/0x4af0 kernel/sched/core.c:6695 preempt_schedule_irq+0xfb/0x1b0 kernel/sched/core.c:7007 irqentry_exit+0x57/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:nd_jump_root+0x2d/0x410 fs/namei.c:960 Code: 41 56 41 55 41 54 53 49 89 ff 49 bc 00 00 00 00 00 fc ff df e8 94 5f 91 ff 4d 8d 77 38 4d 89 f5 49 c1 ed 03 43 0f b6 44 25 00 <84> c0 0f 85 2a 03 00 00 41 8b 1e 89 de 81 e6 00 00 08 00 31 ff e8 RSP: 0018:ffffc9000369f868 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88802d415940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc9000369fbc0 RBP: 000000000000002f R08: ffffffff81fc8444 R09: 1ffffffff20df670 R10: dffffc0000000000 R11: fffffbfff20df671 R12: dffffc0000000000 R13: 1ffff920006d3f7f R14: ffffc9000369fbf8 R15: ffffc9000369fbc0 path_init+0x3cd/0x1230 fs/namei.c:2392 path_openat+0x17f/0x3180 fs/namei.c:3791 do_filp_open+0x234/0x490 fs/namei.c:3823 do_sys_openat2+0x13e/0x1d0 fs/open.c:1422 do_sys_open fs/open.c:1437 [inline] __do_sys_openat fs/open.c:1453 [inline] __se_sys_openat fs/open.c:1448 [inline] __x64_sys_openat+0x247/0x290 fs/open.c:1448 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff6ac4c2a46 RSP: 002b:00007ffc2f504518 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc2f504778 RCX: 00007ff6ac4c2a46 RDX: 0000000000080000 RSI: 00007ffc2f504590 RDI: 00000000ffffff9c RBP: 00007ffc2f504580 R08: 0000000000080000 R09: 00007ffc2f504590 R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffc2f504590 R13: 0000000000000004 R14: 00007ffc2f50475f R15: 00000000ffffffff rcu: rcu_preempt kthread starved for 10490 jiffies! g234841 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:26504 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x196c/0x4af0 kernel/sched/core.c:6695 schedule+0xc3/0x180 kernel/sched/core.c:6771 schedule_timeout+0x1bd/0x300 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x2c6/0x1010 kernel/rcu/tree.c:1613 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1812 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 2418 Comm: kworker/u4:9 Not tainted 6.6.0-rc4-syzkaller-00029-gcbf3a2cb156a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:300 [inline] RIP: 0010:smp_call_function_many_cond+0x1805/0x2890 kernel/smp.c:844 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 64 59 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 9f 55 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 83 55 RSP: 0018:ffffc9000a337720 EFLAGS: 00000293 RAX: ffffffff8182b62d RBX: 1ffff110173282cd RCX: ffff88802529d940 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000a337920 R08: ffffffff8182b5fc R09: 1ffffffff20df670 R10: dffffc0000000000 R11: fffffbfff20df671 R12: dffffc0000000000 R13: ffff8880b9941668 R14: ffff8880b983d440 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8c96233000 CR3: 000000000d130000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1012 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1993 [inline] text_poke_bp_batch+0x350/0xb20 arch/x86/kernel/alternative.c:2203 text_poke_flush arch/x86/kernel/alternative.c:2394 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2401 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x132/0x250 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:830 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x90f/0x1400 kernel/workqueue.c:2703 worker_thread+0xa5f/0xff0 kernel/workqueue.c:2784 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304