rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7506/1:b..l rcu: (detected by 0, t=10502 jiffies, g=15893, q=5151 ncpus=2) task:syz-executor state:R running task stack:22368 pid:7506 tgid:7506 ppid:1 task_flags:0x480140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 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_is_held_type+0x106/0x150 kernel/locking/lockdep.c:5945 Code: 18 00 00 b8 ff ff ff ff 65 0f c1 05 f4 00 2b 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc90003c1f170 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 0000000000000100 RSI: ffffffff8d7c19f2 RDI: ffffffff8ba67a00 RBP: 00000000ffffffff R08: ffffffff89c955c6 R09: ffffffff99b30f70 R10: dffffc0000000000 R11: fffffbfff1ed4e77 R12: 0000000000000246 R13: ffff88801db59e80 R14: ffffffff8ddcba80 R15: 000000000000000b lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0x37/0x480 kernel/sched/core.c:8850 __rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline] rt_spin_lock+0xc2/0x400 kernel/locking/spinlock_rt.c:57 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] addrconf_ifdown+0x3b6/0x1aa0 net/ipv6/addrconf.c:3895 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] netif_close_many+0x2ae/0x420 net/core/dev.c:1804 netif_close_many_and_unlock net/core/dev.c:12331 [inline] unregister_netdevice_many_notify+0x81f/0x2360 net/core/dev.c:12395 unregister_netdevice_many net/core/dev.c:12494 [inline] unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12308 unregister_netdevice include/linux/netdevice.h:3409 [inline] nsim_destroy+0x1e5/0x680 drivers/net/netdevsim/netdev.c:1185 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1528 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1540 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1764 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1779 device_remove drivers/base/dd.c:631 [inline] __device_release_driver drivers/base/dd.c:1344 [inline] device_release_driver_internal+0x46f/0x870 drivers/base/dd.c:1367 bus_remove_device+0x45a/0x570 drivers/base/bus.c:657 device_del+0x52b/0x900 drivers/base/core.c:3880 device_unregister+0x21/0xf0 drivers/base/core.c:3921 nsim_bus_dev_del drivers/net/netdevsim/bus.c:491 [inline] del_device_store+0x2b0/0x370 drivers/net/netdevsim/bus.c:244 kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_write+0x156/0x270 fs/read_write.c:740 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: 0033:0x7f4eea08d04e RSP: 002b:00007fffa1cc40f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000555558b3b500 RCX: 00007f4eea08d04e RDX: 0000000000000001 RSI: 00007fffa1cc4180 RDI: 0000000000000005 RBP: 00007f4eea163514 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fffa1cc4180 R14: 00007f4eeae74620 R15: 0000000000000003 rcu: rcu_preempt kthread timer wakeup didn't happen for 10495 jiffies! g15893 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=13116 rcu: rcu_preempt kthread starved for 10496 jiffies! g15893 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27776 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 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: 0 UID: 0 PID: 7768 Comm: syz.2.401 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__local_bh_enable_ip+0x1c2/0x2b0 kernel/softirq.c:307 Code: f7 89 df e8 60 01 00 00 41 f7 c4 00 02 00 00 74 05 e8 42 80 44 00 9c 58 a9 00 02 00 00 75 23 41 f7 c4 00 02 00 00 74 01 fb 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 e9 66 fe RSP: 0018:ffffc900034ef288 EFLAGS: 00000206 RAX: 0000000000000002 RBX: ffff88801d6a9e80 RCX: 0000000000000046 RDX: 0000000000000006 RSI: ffffffff8d565661 RDI: ffffffff8ba67a00 RBP: 1ffff11003ad5544 R08: ffffffff8f6a73b7 R09: 1ffffffff1ed4e76 R10: dffffc0000000000 R11: fffffbfff1ed4e77 R12: 0000000000000286 R13: dffffc0000000000 R14: ffff88801d6aaa24 R15: 0000000000000001 FS: 00007fdefbb196c0(0000) GS:ffff888126332000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f04862f5000 CR3: 000000003c792000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000080083 DR3: ffffffffefffff16 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: local_bh_enable include/linux/bottom_half.h:33 [inline] rt_spin_trylock_bh+0x1dd/0x2e0 kernel/locking/spinlock_rt.c:129 tipc_sk_rcv+0x498/0x2bb0 net/tipc/socket.c:2496 tipc_node_xmit+0x227/0xf10 net/tipc/node.c:1701 tipc_node_xmit_skb net/tipc/node.c:1766 [inline] tipc_node_distr_xmit+0x2e5/0x420 net/tipc/node.c:1781 tipc_group_join+0x570/0x710 net/tipc/group.c:208 tipc_sk_join+0x478/0x6a0 net/tipc/socket.c:3102 tipc_setsockopt+0x73e/0x990 net/tipc/socket.c:3200 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2322 __sys_setsockopt net/socket.c:2347 [inline] __do_sys_setsockopt net/socket.c:2353 [inline] __se_sys_setsockopt net/socket.c:2350 [inline] __x64_sys_setsockopt+0x143/0x1b0 net/socket.c:2350 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: 0033:0x7fdefdd2c819 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:00007fdefbb19028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fdefdfa6270 RCX: 00007fdefdd2c819 RDX: 0000000000000087 RSI: 000000000000010f RDI: 000000000000000a RBP: 00007fdefddc2c91 R08: 0000000000000010 R09: 0000000000000000 R10: 0000200000000440 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdefdfa6308 R14: 00007fdefdfa6270 R15: 00007fffedf46948