rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P60/1:b..l rcu: (detected by 0, t=10502 jiffies, g=21497, q=1574 ncpus=2) task:kworker/u8:4 state:R running task stack:24456 pid:60 tgid:60 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:ndisc_send_skb+0xae6/0x1440 net/ipv6/ndisc.c:510 Code: 4d 85 f6 0f 84 12 04 00 00 e8 76 f8 8b f7 49 8d 9e f0 06 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 80 65 ef f7 48 8b 03 65 48 ff 40 40 48 8b 44 24 RSP: 0018:ffffc9000211f660 EFLAGS: 00000246 RAX: 1ffff110081306de RBX: ffff8880409836f0 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000211f850 R08: ffff888075104d37 R09: 1ffff1100ea209a6 R10: dffffc0000000000 R11: ffffed100ea209a7 R12: 0000000000001000 R13: ffff88807d250000 R14: ffff888040983000 R15: ffff888075104d28 addrconf_dad_completed+0x7ae/0xd60 net/ipv6/addrconf.c:4360 addrconf_dad_work+0xc36/0x14b0 net/ipv6/addrconf.c:-1 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 1723 jiffies! g21497 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 3419 Comm: kworker/R-bat_e Not tainted 6.17.0-rc1-syzkaller-g8742b2d8935f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 ab 86 4b f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f3 2d 14 f6 65 8b 05 6c 71 24 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90000007900 EFLAGS: 00000206 RAX: a730d483a9d53100 RBX: 0000000000000212 RCX: a730d483a9d53100 RDX: 0000000000000002 RSI: ffffffff8d9b6d9d RDI: 0000000000000001 RBP: ffffc90000007990 R08: ffffffff8fa37e37 R09: 1ffffffff1f46fc6 R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: dffffc0000000000 R13: 000000000000d000 R14: ffff8881437e4000 R15: 1ffff92000000f20 FS: 0000000000000000(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4796995263 CR3: 0000000030938000 CR4: 0000000000350ef0 Call Trace: spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] dummy_timer+0x441f/0x4550 drivers/usb/gadget/udc/dummy_hcd.c:-1 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline] RIP: 0010:__local_bh_enable_ip+0x135/0x1c0 kernel/softirq.c:414 Code: 8b e8 9f 6a f4 09 65 66 8b 05 4f 58 1b 11 66 85 c0 75 5a bf 01 00 00 00 e8 b8 14 0b 00 e8 43 6d 42 00 fb 65 8b 05 2b 58 1b 11 <85> c0 75 05 e8 e2 de ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc9000bf47940 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000000000000201 RCX: a730d483a9d53100 RDX: 0000000000000006 RSI: ffffffff8d9b6d9d RDI: ffffffff8be33400 RBP: ffffc9000bf479c8 R08: ffffffff8fa37e37 R09: 1ffffffff1f46fc6 R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: ffffffff8b49dce1 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920017e8f28 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline] batadv_tt_purge+0x4d1/0x9e0 net/batman-adv/translation-table.c:3510 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 rescuer_thread+0x53c/0xdd0 kernel/workqueue.c:3496 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245