rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5197/1:b..l rcu: (detected by 0, t=10502 jiffies, g=15885, q=595 ncpus=2) task:udevd state:R running task stack:23840 pid:5197 tgid:5197 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__kernel_text_address+0x34/0x40 kernel/extable.c:92 Code: 00 00 00 85 c0 0f 95 c0 48 c7 c1 00 10 79 91 48 39 cb 0f 93 c1 48 c7 c2 1f 17 94 91 48 39 d3 0f 92 c2 20 ca 08 c2 0f b6 c2 5b 52 27 86 0a 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90004556f18 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc90004556f88 RCX: ffffffff91791000 RDX: ffffffff91941701 RSI: ffffc90004550000 RDI: ffffffff81fa5d16 RBP: ffffc90004556fd0 R08: ffffc900045574c8 R09: ffffc90004556f90 R10: dffffc0000000000 R11: fffff520008aadf4 R12: ffff88807cee8000 R13: ffffffff818b39e0 R14: dffffc0000000000 R15: 1ffff920008aadf1 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2657 discard_slab mm/slub.c:2688 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3157 put_cpu_partial+0x17c/0x250 mm/slub.c:3232 __slab_free+0x290/0x380 mm/slub.c:4483 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] __do_kmalloc_node mm/slub.c:4297 [inline] __kmalloc_noprof+0x236/0x4c0 mm/slub.c:4310 kmalloc_noprof include/linux/slab.h:905 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x258/0x4f0 security/tomoyo/file.c:771 security_file_open+0xac/0x250 security/security.c:3105 do_dentry_open+0x328/0x1b70 fs/open.c:928 vfs_open+0x3e/0x330 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f704c51a477 RSP: 002b:00007ffde38be9b8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000559c38ee4ec0 RCX: 00007f704c51a477 RDX: 0000000000090800 RSI: 0000559c38ee3720 RDI: 00000000ffffff9c RBP: 0000559c38ef52b0 R08: 0000000000090800 R09: 0000559c38ee3720 R10: 0000000000000000 R11: 0000000000000287 R12: 0000559c38ee3720 R13: 00000000000000fe R14: 0000559c173ac1c4 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 9524 jiffies! g15885 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:26264 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 5891 Comm: kworker/0:6 Not tainted 6.13.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 ae b1 3a f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 53 57 a2 f5 65 8b 05 f4 aa 38 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc900000078c0 EFLAGS: 00000206 RAX: 0ab1684d86c8ef00 RBX: 1ffff92000000f1c RCX: ffffffff817b275a RDX: dffffc0000000000 RSI: ffffffff8c0a96c0 RDI: 0000000000000001 RBP: ffffc90000007950 R08: ffffffff942a1947 R09: 1ffffffff2854328 R10: dffffc0000000000 R11: fffffbfff2854329 R12: dffffc0000000000 R13: 1ffff92000000f18 R14: ffffc900000078e0 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fb0fff8 CR3: 000000000e736000 CR4: 0000000000350ef0 Call Trace: dummy_timer+0x44d6/0x4620 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59d/0xd30 kernel/time/hrtimer.c:1803 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1820 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319 Code: 0a 8c 48 c7 c6 60 ba 0a 8c e8 ec a6 97 f5 90 0f 0b 90 90 90 eb c6 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 31 c0 83 3d 77 09 51 04 00 74 1e 83 3d 1a 3b 51 04 00 RSP: 0018:ffffc90004057a18 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff8fdbe600 RCX: ffff8880353d0000 RDX: 0000000000000000 RSI: ffffffff8c0aa8c0 RDI: ffffffff8c5faaa0 RBP: ffffc90004057b28 R08: ffffffff942a1947 R09: 1ffffffff2854328 R10: dffffc0000000000 R11: fffffbfff2854329 R12: 0000000000000000 R13: dffffc0000000000 R14: 00000000000003c9 R15: 1ffff9200080af4c __might_resched+0xdf/0x780 kernel/sched/core.c:8720 neigh_periodic_work+0xbde/0xde0 net/core/neighbour.c:969 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244