ip6_tunnel: ip6gretap0: Local routing loop detected! ------------[ cut here ]------------ 1 WARNING: kernel/rcu/tree_stall.h:1048 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048, CPU#0: kworker/0:4/5619 Modules linked in: CPU: 0 UID: 0 PID: 5619 Comm: kworker/0:4 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 Workqueue: events jump_label_update_timeout RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048 Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 80 15 73 9b e8 c0 18 8c 00 b8 01 00 00 00 87 05 35 d2 84 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 64 70 22 91 48 81 fd c0 14 bf 8e 74 5a 48 b8 00 RSP: 0018:ffffc90000007df0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ee4340 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b731580 RBP: ffffffff8ebf14c0 R08: 0000000000000001 R09: fffffbfff36e62b0 R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1d01e50 R13: 0000000000000246 R14: 0000000000000200 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123de8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f62c8cd5278 CR3: 000000000e992000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1011 [inline] rcu_core+0x2cb/0x10d0 kernel/rcu/tree.c:2892 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x589/0x16c0 kernel/smp.c:892 Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 c9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31 RSP: 0018:ffffc90004437938 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fd46fd RDX: ffff88807a724a80 RSI: ffffffff81fd46d7 RDI: ffff88807a724a80 RBP: ffff8880b8541240 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170a8249 R14: 0000000000000001 R15: ffff8880b843c880 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline] smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x37a/0x550 kernel/jump_label.c:910 __static_key_slow_dec_cpuslocked.part.0+0xc5/0xf0 kernel/jump_label.c:315 __static_key_slow_dec_cpuslocked kernel/jump_label.c:297 [inline] __static_key_slow_dec kernel/jump_label.c:321 [inline] jump_label_update_timeout+0x41/0x50 kernel/jump_label.c:329 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: b8 00 00 00 00 mov $0x0,%eax 5: 00 fc add %bh,%ah 7: ff lcall (bad) 8: df 48 8b fisttps -0x75(%rax) b: 54 push %rsp c: 24 08 and $0x8,%al e: 49 89 d5 mov %rdx,%r13 11: 49 89 d4 mov %rdx,%r12 14: 49 c1 ed 03 shr $0x3,%r13 18: 41 83 e4 07 and $0x7,%r12d 1c: 49 01 c5 add %rax,%r13 1f: 41 83 c4 03 add $0x3,%r12d 23: e8 c9 95 0c 00 call 0xc95f1 28: f3 90 pause * 2a: 41 0f b6 45 00 movzbl 0x0(%r13),%eax <-- trapping instruction 2f: 41 38 c4 cmp %al,%r12b 32: 7c 08 jl 0x3c 34: 84 c0 test %al,%al 36: 0f 85 2c 0f 00 00 jne 0xf68 3c: 8b 45 08 mov 0x8(%rbp),%eax 3f: 31 .byte 0x31