rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2/1:b..l P4681/1:b..l rcu: (detected by 1, t=10502 jiffies, g=17713, q=1374240 ncpus=2) task:udevd state:R running task stack:21664 pid:4681 tgid:4681 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7004 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:__reset_page_owner+0x5e/0x430 mm/page_owner.c:295 Code: 84 93 03 00 00 49 89 c7 49 bd 00 00 00 00 00 fc ff df 48 8b 05 53 a2 9d 0c 49 8d 5c 07 08 48 89 d8 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 8d 03 00 00 8b 03 89 44 24 20 bf 00 28 00 00 e8 ca 03 RSP: 0018:ffffc90003f37b48 EFLAGS: 00000212 RAX: 0000000000000000 RBX: ffff88801c5b2b10 RCX: ffff88807ae50000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff820b66ca R09: 1ffffffff2858f00 R10: dffffc0000000000 R11: fffffbfff2858f01 R12: 0000000000000003 R13: dffffc0000000000 R14: 1ffffd400016b781 R15: ffff88801c5b2b00 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 __slab_free+0x31b/0x3d0 mm/slub.c:4490 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:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 getname_flags+0xb7/0x540 fs/namei.c:139 do_readlinkat+0xd8/0x3a0 fs/stat.c:536 __do_sys_readlink fs/stat.c:574 [inline] __se_sys_readlink fs/stat.c:571 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:571 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: 0033:0x7fcbfa717d47 RSP: 002b:00007ffee62518d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffee62518e8 RCX: 00007fcbfa717d47 RDX: 0000000000000400 RSI: 00007ffee62518e8 RDI: 00007ffee6251dc8 RBP: 0000000000000400 R08: 000055b18a1eeb14 R09: 0000000000000000 R10: 0000000000000812 R11: 0000000000000246 R12: 00007ffee6251dc8 R13: 00007ffee6251d38 R14: 000055b18a1dd910 R15: 0000000000000000 task:kthreadd state:R running task stack:23920 pid:2 tgid:2 ppid:0 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_notrace+0x100/0x140 kernel/sched/core.c:6954 preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7e/0xb0 kernel/rcu/tree.c:738 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xe3/0x550 kernel/locking/lockdep.c:5796 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __reset_page_owner+0x30/0x430 mm/page_owner.c:290 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 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:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 copy_signal+0x51/0x650 kernel/fork.c:1841 copy_process+0x17ee/0x3d50 kernel/fork.c:2369 kernel_clone+0x226/0x8f0 kernel/fork.c:2784 kernel_thread+0x1bc/0x240 kernel/fork.c:2846 create_kthread kernel/kthread.c:412 [inline] kthreadd+0x60d/0x810 kernel/kthread.c:767 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: rcu_preempt kthread starved for 10539 jiffies! g17713 f0x2 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:24272 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5290 Comm: kworker/0:4 Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:389 Code: 8c e8 e4 27 6e 0a 65 66 8b 05 84 49 ac 7e 66 85 c0 75 5d bf 01 00 00 00 e8 3d af 0b 00 e8 f8 1c 45 00 fb 65 8b 05 48 49 ac 7e <85> c0 75 05 e8 e7 27 a9 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c RSP: 0018:ffffc90000007580 EFLAGS: 00000282 RAX: 0000000080000101 RBX: 1ffff92000000eb4 RCX: ffffffff8170ce6a RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: ffffffff8c60fb20 RBP: ffffc90000007630 R08: ffffffff942c78b7 R09: 1ffffffff2858f16 R10: dffffc0000000000 R11: fffffbfff2858f17 R12: dffffc0000000000 R13: 1ffff92000000eb8 R14: ffffc900000075c0 R15: 0000000000000200 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32e1dff8 CR3: 00000000602de000 CR4: 0000000000350ef0 Call Trace: local_bh_enable include/linux/bottom_half.h:33 [inline] ipt_do_table+0x1552/0x1860 net/ipv4/netfilter/ip_tables.c:357 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __napi_poll+0xcd/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 neigh_periodic_work+0xb35/0xd50 net/core/neighbour.c:1019 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 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