rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l rcu: (detected by 0, t=10503 jiffies, g=38465, q=777 ncpus=2) task:kworker/u8:0 state:R running task stack:22984 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 3b df 7d 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 86 c4 3c 0f 0f 82 ac 02 00 00 8b 35 4e f8 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd de 7d 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0018:ffffc90000117a30 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e17cd15 RDI: ffffffff8c400c80 RBP: ffffffff8ebe6100 R08: 000000005edc0ddd R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:784 [inline] batadv_iv_ogm_schedule_buff+0x5a4/0x15e0 net/batman-adv/bat_iv_ogm.c:862 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:918 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:911 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x548/0x800 net/batman-adv/bat_iv_ogm.c:1807 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 rcu: rcu_preempt kthread starved for 9241 jiffies! g38465 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27432 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 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 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5714 Comm: kworker/1:3 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_power_efficient check_lifetime RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:430 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x434/0xc00 kernel/locking/qspinlock.c:325 Code: 01 00 00 66 89 8c 24 80 00 00 00 41 0f b6 45 00 44 38 f8 7f 08 84 c0 0f 85 c8 06 00 00 0f b6 03 84 c0 0f 84 84 00 00 00 f3 90 <41> 83 ec 01 75 ce 48 b8 00 00 00 00 00 fc ff df 48 8b 74 24 20 48 RSP: 0018:ffffc90000a085f0 EFLAGS: 00000206 RAX: 0000000000000003 RBX: ffff88807f553940 RCX: 0000000000000100 RDX: 0000000000000001 RSI: ffffffff81b6fe0a RDI: ffffffff8c400c80 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000001a03 R13: ffffed100feaa728 R14: ffff8880b853c4c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000002c000 CR3: 0000000026bd8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline] queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x1e0/0x260 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:342 [inline] __netif_tx_lock include/linux/netdevice.h:4809 [inline] __dev_queue_xmit+0x19b7/0x4940 net/core/dev.c:4866 dev_queue_xmit include/linux/netdevice.h:3446 [inline] can_send+0x5d7/0xbd0 net/can/af_can.c:279 can_can_gw_rcv net/can/gw.c:569 [inline] can_can_gw_rcv+0x820/0xca0 net/can/gw.c:458 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0x153/0x890 net/can/af_can.c:602 can_receive+0x2cb/0x500 net/can/af_can.c:674 can_rcv+0x29e/0x300 net/can/af_can.c:699 __netif_receive_skb_one_core+0x1b2/0x1e0 net/core/dev.c:6206 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6319 process_backlog+0x37a/0x1580 net/core/dev.c:6670 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7949 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:__schedule+0x0/0x6730 kernel/sched/core.c:7062 Code: c1 c0 f6 e9 43 ff ff ff e8 ed c1 c0 f6 e9 74 ff ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 41 57 41 56 48 8d 85 78 ff ff ff 41 55 48 c1 e8 03 41 RSP: 0018:ffffc90005127a90 EFLAGS: 00000202 RAX: 000000000036536d RBX: ffffed1004c4c000 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffffffff8e1a29fc RDI: 0000000000000001 RBP: ffff888026260000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:313 Code: 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 58 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 2a fe ff ff RSP: 0018:ffffc90005127ba8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88801cf68370 R08: 000000001925ffa7 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000000 R13: 000000000000006e R14: 0000000000000280 R15: dffffc0000000000 rcu_read_lock include/linux/rcupdate.h:841 [inline] check_lifetime+0xd7/0xab0 net/ipv4/devinet.c:725 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