rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=21321, q=179 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294970337-4294959835), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g21321 f0x2 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:27504 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5740 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 53 Comm: kworker/u8:3 Not tainted 6.12.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:mark_usage kernel/locking/lockdep.c:4624 [inline] RIP: 0010:__lock_acquire+0x882/0x3ce0 kernel/locking/lockdep.c:5156 Code: 0c 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 28 33 00 00 <41> 0f b6 45 22 a8 18 75 6b a8 03 0f 85 72 09 00 00 ba 02 00 00 00 RSP: 0018:ffffc90000007b38 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88801b18d422 RCX: 1ffffffff2dd89e6 RDX: 0000000000000002 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 000000000000004b R08: 0000000000000000 R09: fffffbfff2dc5db7 R10: ffffffff96e2edbf R11: 0000000000000000 R12: ffff88801b18d3f9 R13: ffff88801b18d400 R14: 0000000000000002 R15: ffff88801b18c880 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3b20ac CR3: 0000000074670000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd8/0xc60 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire.part.0+0x155/0x380 kernel/locking/lockdep.c:5790 Code: b8 ff ff ff ff 65 0f c1 05 70 de 97 7e 83 f8 01 0f 85 d0 01 00 00 9c 58 f6 c4 02 0f 85 e5 01 00 00 48 85 ed 0f 85 b6 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7 RSP: 0018:ffffc90000be7a78 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 1ffff9200017cf50 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b6cd2a0 RDI: ffffffff8bd1b380 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2dc5d88 R10: ffffffff96e2ec47 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e1b8340 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline] batadv_iv_ogm_schedule_buff+0x5ac/0x14d0 net/batman-adv/bat_iv_ogm.c:825 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:868 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:861 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x31e/0x8d0 net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244