ip6_tunnel: ip6gre2 xmit: Local address not yet configured! rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=28dc/1/0x4000000000000000 softirq=94915/94946 fqs=0 rcu: (detected by 0, t=10505 jiffies, g=82453, q=1110 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 21721 Comm: syz.2.4060 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:752 Code: e8 fb f7 fc 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 c7 27 8e 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 9c 60 86 00 48 c7 c3 d8 78 3b 93 49 03 1e 48 89 RSP: 0018:ffffc90000a08c50 EFLAGS: 00000046 RAX: 1ffffffff1c4f8fb RBX: 0000000000000001 RCX: 0000000000010002 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: ffffffff8c2910c0 RBP: ffffffff89b61a88 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed1005245456 R12: 0000000000000002 R13: ffffffff8e959a20 R14: ffffffff8e27c7d8 R15: dffffc0000000000 FS: 00007f11643406c0(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0be79af708 CR3: 0000000079626000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:23 [inline] lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] advance_sched+0xa04/0xc80 net/sched/sch_taprio.c:992 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:check_preemption_disabled+0x21/0xe0 lib/smp_processor_id.c:53 Code: 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 07 5e 92 07 65 8b 0d fc 5d 92 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f <5d> e9 59 e2 02 00 cc 9c 59 f7 c1 00 02 00 00 74 ea 65 4c 8b 3d ae RSP: 0018:ffffc900036ef768 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff933c4ec0 RCX: 0000000080000001 RDX: 0000000000000017 RSI: ffffffff8c291100 RDI: ffffffff8c2910c0 RBP: 0000000000000000 R08: dffffc0000000000 R09: 0000000000000000 R10: ffffed100d26b000 R11: fffffbfff20622df R12: ffffea0001a4d600 R13: ffff88813fffb900 R14: ff000fffffffffff R15: 0000000000000000 __free_frozen_pages+0x6e6/0xd20 mm/page_alloc.c:2963 __slab_free+0x274/0x2c0 mm/slub.c:5672 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 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:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] __kmalloc_cache_noprof+0x2b6/0x660 mm/slub.c:5446 _kmalloc_noprof include/linux/slab.h:969 [inline] _kzalloc_noprof include/linux/slab.h:1286 [inline] task_numa_work+0x9be/0x15b0 kernel/sched/fair.c:4200 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x1181/0x12c0 kernel/signal.c:2810 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f116339ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1164340028 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffea RBX: 00007f1163615fa0 RCX: 00007f116339ce59 RDX: 000000000000006f RSI: 0000000000000084 RDI: 0000000000000003 RBP: 00007f1163432e6f R08: 0000200000000640 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1163616038 R14: 00007f1163615fa0 R15: 00007fff156d9e58 rcu: rcu_preempt kthread starved for 10505 jiffies! g82453 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:28120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 0 UID: 0 PID: 16751 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x10b0/0x14b0 kernel/smp.c:892 Code: c0 75 73 41 8b 1e 89 de 83 e6 01 31 ff e8 98 02 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 44 fe 0b 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 29 fe 0b RSP: 0018:ffffc9000ffdf460 EFLAGS: 00000293 RAX: ffffffff81b9f7f7 RBX: dffffc0000000000 RCX: ffff888037fb1f00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000ffdf588 R08: ffffffff903116f7 R09: 1ffffffff20622de R10: dffffc0000000000 R11: fffffbfff20622df R12: 1ffff110170e8199 R13: ffff8880b863c2c8 R14: ffff8880b8740cc8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88812527c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdf539ea2f8 CR3: 000000000e746000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x5c4/0x1090 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline] tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423 tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:549 free_ldt_pgtables+0x192/0x360 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:229 [inline] exit_mmap+0x1bf/0x9f0 mm/mmap.c:1285 __mmput+0x118/0x420 kernel/fork.c:1181 exit_mm+0x221/0x2d0 kernel/exit.c:610 do_exit+0x6cd/0x2360 kernel/exit.c:992 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3038 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f822e53e3e7 Code: Unable to access opcode bytes at 0x7f822e53e3bd. RSP: 002b:00007ffd67b34c98 EFLAGS: 00000297 ORIG_RAX: 000000000000003e RAX: 0000000000000000 RBX: 000000000000031c RCX: 00007f822e53e3e7 RDX: 0000000000000387 RSI: 0000000000000009 RDI: 00000000fffffce4 RBP: 00007ffd67b34cdc R08: 0000000035dde5da R09: 0000000000000000 R10: 4000000000000000 R11: 0000000000000297 R12: 0000000000000103 R13: 0000000000000064 R14: 0000000000086bdf R15: 00007ffd67b34d30