rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17096/1:b..l P5974/1:b..l rcu: (detected by 1, t=10502 jiffies, g=153509, q=1003 ncpus=2) task:udevd state:R running task stack:22608 pid:5974 tgid:5974 ppid:5189 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3d0 kernel/locking/lockdep.c:5893 Code: 88 7a 11 00 00 00 00 eb b5 e8 55 85 0c 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 d5 42 7a 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 a5 83 6e ff cc 48 8d 3d 82 34 73 RSP: 0018:ffffc900045af060 EFLAGS: 00000286 RAX: 96ea79fcfc611300 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000002 RSI: ffffffff8e167641 RDI: ffffffff8c27be00 RBP: ffff888027246728 R08: ffffc900045af1c7 R09: ffffc900045af1b8 R10: dffffc0000000000 R11: fffff520008b5e39 R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff8e75e520 R15: ffff888027245b80 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5573 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873 mt_alloc_one lib/maple_tree.c:174 [inline] mas_alloc_nodes+0x291/0x350 lib/maple_tree.c:1110 mas_preallocate+0x2d6/0x640 lib/maple_tree.c:5194 vma_iter_prealloc mm/vma.h:568 [inline] commit_merge+0x21d/0x730 mm/vma.c:751 vma_merge_existing_range mm/vma.c:976 [inline] vma_modify+0x15d0/0x2060 mm/vma.c:1657 vma_modify_flags+0x24b/0x330 mm/vma.c:1700 mprotect_fixup+0x47a/0xa80 mm/mprotect.c:756 do_mprotect_pkey+0x8ab/0xcd0 mm/mprotect.c:930 __do_sys_mprotect mm/mprotect.c:951 [inline] __se_sys_mprotect mm/mprotect.c:948 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:948 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f668c11dfe7 RSP: 002b:00007ffd8ca72338 EFLAGS: 00000246 ORIG_RAX: 000000000000000a RAX: ffffffffffffffda RBX: 0000000000000200 RCX: 00007f668c11dfe7 RDX: 0000000000000001 RSI: 0000000000000200 RDI: 00007f668c7a6000 RBP: 000055a522659130 R08: 0000000000000000 R09: 0000000000000200 R10: 000055a522659190 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000200 R14: 000055a522642a98 R15: 00007f668c93239c task:syz-executor state:R running task stack:21608 pid:17096 tgid:17096 ppid:17091 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_read_lock include/linux/rcupdate.h:851 [inline] RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1193 [inline] RIP: 0010:unwind_next_frame+0xc6/0x23c0 arch/x86/kernel/unwind_orc.c:495 Code: 34 00 4c 8d 3d 00 00 00 00 48 c7 c7 20 e5 75 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 41 57 e8 5e 0b 2b 00 48 83 c4 08 45 c9 37 0a 85 c0 74 3a e8 7c 35 34 00 84 c0 75 31 e8 33 c9 37 RSP: 0018:ffffc90006fd7098 EFLAGS: 00000282 RAX: bb922d70a4bfdf00 RBX: ffffffff81b0c1d9 RCX: 0000000000000046 RDX: 000000004cbb32b3 RSI: ffffffff8e167641 RDI: ffffffff8c27be00 RBP: dffffc0000000000 R08: ffffffff81767e95 R09: ffffffff8e75e520 R10: dffffc0000000000 R11: ffffffff81b0c240 R12: 1ffff92000dfae2d R13: ffffc90006fd71a0 R14: ffffc90006fd7168 R15: ffffffff81767e95 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5573 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5260 [inline] __kmalloc_node_noprof+0x4e0/0x7c0 mm/slub.c:5266 kmalloc_node_noprof include/linux/slab.h:1081 [inline] __vmalloc_area_node mm/vmalloc.c:3855 [inline] __vmalloc_node_range_noprof+0x5d5/0x1730 mm/vmalloc.c:4064 __vmalloc_node_noprof mm/vmalloc.c:4124 [inline] vzalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4202 alloc_counters+0x64/0x5d0 net/ipv4/netfilter/ip_tables.c:799 copy_entries_to_user net/ipv4/netfilter/arp_tables.c:681 [inline] get_entries net/ipv4/netfilter/arp_tables.c:867 [inline] do_arpt_get_ctl+0xa9a/0x1100 net/ipv4/netfilter/arp_tables.c:1461 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x19e/0x230 net/ipv4/ip_sockglue.c:1777 do_sock_getsockopt+0x2d3/0x3f0 net/socket.c:2383 __sys_getsockopt net/socket.c:2412 [inline] __do_sys_getsockopt net/socket.c:2419 [inline] __se_sys_getsockopt net/socket.c:2416 [inline] __x64_sys_getsockopt+0x1a4/0x240 net/socket.c:2416 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f609039df6a RSP: 002b:00007ffce3252e08 EFLAGS: 00000212 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f609039df6a RDX: 0000000000000061 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffce3252e70 R08: 00007ffce3252e1c R09: 0000000000000000 R10: 00007ffce3252e70 R11: 0000000000000212 R12: 00007ffce3252e1c R13: 00007f60904336e7 R14: 00000000001b6b46 R15: 00007ffce3253560 rcu: rcu_preempt kthread starved for 10141 jiffies! g153509 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:28120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 0a da f0 f5 48 89 df e8 42 4f f1 f5 e8 4d a7 1c f6 fb bf 01 00 00 00 42 0c e3 f5 65 8b 05 9b 1f 6b 07 85 c0 74 07 5b e9 6c 60 5f f5 RSP: 0018:ffffc90000a08c00 EFLAGS: 00000206 RAX: 00000000049e9bee RBX: ffff8880b873c9f8 RCX: 0000000080000102 RDX: 0000000000000000 RSI: ffffffff8def6aec RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff90119ab7 R09: 1ffffffff2023356 R10: dffffc0000000000 R11: fffffbfff2023357 R12: ffff8880b873c850 R13: ffff8880b873c828 R14: ffffffff89805a4b R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125560000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f668c7a6000 CR3: 0000000093851000 CR4: 0000000000350ef0 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] backlog_unlock_irq_enable net/core/dev.c:266 [inline] process_backlog+0x140c/0x1950 net/core/dev.c:6657 __napi_poll+0xae/0x340 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7912 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: be 6c 02 e9 8e 02 62 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 22 1b 00 fb f4 67 02 62 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000246 RAX: 00000000049e9a2b RBX: ffffffff819a8e5a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8def6aec RDI: ffffffff8c27be00 RBP: ffffc90000197f10 R08: ffff8880b873395b R09: 1ffff110170e672b R10: dffffc0000000000 R11: ffffed10170e672c R12: ffffffff90119ab0 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003ad0000 arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ba/0x5d0 kernel/sched/idle.c:341 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:439 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147