rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=f9dc/1/0x4000000000000000 softirq=32431/32432 fqs=0 (detected by 1, t=10505 jiffies, g=44793, q=159 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8887 Comm: kworker/u4:11 Not tainted 6.1.91-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc3/0x130 kernel/locking/spinlock.c:194 Code: 4c 89 f7 e8 8f e2 4c f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 f2 e1 4c f7 f6 44 24 21 02 <75> 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 e8 d7 28 c9 f6 RSP: 0018:ffffc90000007ca0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff92000000f98 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff91ea26f0 RBP: ffffc90000007d28 R08: dffffc0000000000 R09: fffffbfff23d44df R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff92000000f94 R14: ffffc90000007cc0 R15: 0000000000000046 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa7e0779bf8 CR3: 000000001fb91000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:481 __run_hrtimer kernel/time/hrtimer.c:1654 [inline] __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:__rcu_read_unlock+0xa/0x100 kernel/rcu/tree_plugin.h:419 Code: e1 07 80 c1 03 38 c1 7c b0 4c 89 ff e8 3f fa 6d 00 eb a6 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 41 57 41 56 41 55 41 54 53 <49> bc 00 00 00 00 00 fc ff df 65 4c 8b 35 94 5c 8e 7e 4d 8d ae 3c RSP: 0018:ffffc90006347a28 EFLAGS: 00000293 RAX: ffffffff8a5709d2 RBX: 0000000000000001 RCX: ffff88805d353b80 RDX: 0000000000000000 RSI: ffffffff8b3d4540 RDI: ffffffff8b3d4500 RBP: ffffc90006347b98 R08: ffffffff8a5709c0 R09: fffffbfff2093845 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801f1bc800 R13: ffff88805a970ec0 R14: dffffc0000000000 R15: ffff88807e090128 rcu_read_unlock include/linux/rcupdate.h:823 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:772 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:826 [inline] batadv_iv_ogm_schedule+0x6e3/0x1090 net/batman-adv/bat_iv_ogm.c:869 batadv_iv_send_outstanding_bat_ogm_packet+0x6fa/0x800 net/batman-adv/bat_iv_ogm.c:1713 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: rcu_preempt kthread starved for 10505 jiffies! g44793 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:27032 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 8976 Comm: kworker/u4:12 Not tainted 6.1.91-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1fb0/0x3460 kernel/smp.c:998 Code: 2f 44 89 ee 83 e6 01 31 ff e8 ec 42 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 77 3f 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc90009cf75a0 EFLAGS: 00000293 RAX: ffffffff817f4dfb RBX: 1ffff1101730859d RCX: ffff888079d00000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90009cf7980 R08: ffffffff817f4dc4 R09: fffffbfff2093845 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b9842ce8 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbfe8978198 CR3: 000000000ce8e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1334 [inline] text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308