ip6_tunnel: ip6tnl3 xmit: Local address not yet configured! rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22397/1:b..l rcu: (detected by 1, t=10503 jiffies, g=112373, q=1474 ncpus=2) task:syz.0.4075 state:R running task stack:25464 pid:22397 tgid:22396 ppid:18851 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:867 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1181 [inline] RIP: 0010:kernfs_root+0x152/0x230 fs/kernfs/kernfs-internal.h:79 Code: 74 08 4c 89 f7 e8 6e 18 c1 ff 4d 8b 36 e8 96 c3 39 09 89 c5 31 ff 89 c6 e8 db c3 55 ff 85 ed 74 10 e8 d2 d5 3a ff 84 c0 74 0e 89 bf 55 ff eb 7d e8 82 bf 55 ff eb 76 e8 6b c3 39 09 89 c5 31 RSP: 0018:ffffc9000d7df878 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff826ff5ec RCX: 0000000080000001 RDX: ffff88802fe99f00 RSI: ffffffff8c28b9c0 RDI: ffffffff8c28b980 RBP: 0000000000000001 R08: ffffffff826ff5ec R09: ffffffff8e95cc20 R10: dffffc0000000000 R11: ffffed10037d1a36 R12: dffffc0000000000 R13: ffff888093506d20 R14: ffff88801be8d000 R15: ffff88803599e2d0 __kernfs_remove+0x4ea/0x8e0 fs/kernfs/dir.c:1590 kernfs_remove_by_name_ns+0xc0/0x140 fs/kernfs/dir.c:1798 kernfs_remove_by_name include/linux/kernfs.h:639 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352 destroy_port drivers/infiniband/core/sysfs.c:1233 [inline] ib_free_port_attrs+0x281/0x3b0 drivers/infiniband/core/sysfs.c:1363 remove_one_compat_dev drivers/infiniband/core/device.c:1011 [inline] rdma_dev_exit_net+0x1de/0x350 drivers/infiniband/core/device.c:1149 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252 setup_net+0x2f0/0x340 net/core/net_namespace.c:462 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:579 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:132 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234 ksys_unshare+0x57d/0x9f0 kernel/fork.c:3242 __do_sys_unshare kernel/fork.c:3316 [inline] __se_sys_unshare kernel/fork.c:3314 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3314 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f87ab59ce59 RSP: 002b:00007f87ac3c4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f87ab815fa0 RCX: 00007f87ab59ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000 RBP: 00007f87ab632d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f87ab816038 R14: 00007f87ab815fa0 R15: 00007fff89921f98 rcu: rcu_preempt kthread starved for 6141 jiffies! g112373 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 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+0x389/0x470 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3234 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:__preempt_count_add kernel/rcu/tree.c:748 [inline] RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:751 Code: e8 1f 2b 44 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 30 83 8e 11 e8 cb 04 ff 09 89 c3 83 f8 08 73 65 RSP: 0018:ffffc90000006d08 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff90c50c01 RCX: ffff88803211be00 RDX: ffffc90000006e01 RSI: dffffc0000000000 RDI: ffffc90000006e50 RBP: dffffc0000000000 R08: ffffc90000006e38 R09: 0000000000000000 R10: ffffc90000006e98 R11: fffff52000000dd5 R12: ffffc90000006e48 R13: ffffc90000000000 R14: ffffc90000006e48 R15: ffffffff8176e256 FS: 0000000000000000(0000) GS:ffff88812528b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7af2a6d547 CR3: 000000000e74a000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:867 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x1b76/0x2550 arch/x86/kernel/unwind_orc.c:709 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4951 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1386 [inline] synproxy_send_client_synack+0x172/0xe30 net/netfilter/nf_synproxy_core.c:465 nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1ae0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6203 [inline] __netif_receive_skb net/core/dev.c:6316 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6667 __napi_poll+0xae/0x340 net/core/dev.c:7726 napi_poll net/core/dev.c:7789 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7946 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1363 batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3557 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 rescuer_thread+0x827/0x1130 kernel/workqueue.c:3621 kthread+0x389/0x470 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 ip6_tunnel: ip6tnl2 xmit: Local address not yet configured!