rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4711/1:b..l (detected by 1, t=10502 jiffies, g=10333, q=139) task:syz-executor state:R running task stack:21432 pid: 4711 ppid: 4701 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:756 [inline] RIP: 0010:batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:826 [inline] RIP: 0010:batadv_iv_ogm_schedule+0x4bc/0x1000 net/batman-adv/bat_iv_ogm.c:869 Code: be e5 02 00 00 48 c7 c2 40 4c bf 8b e8 bd d3 4b f7 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 c7 14 b3 f7 49 8b 1e <48> 85 db 0f 84 68 01 00 00 48 81 c3 38 fe ff ff 0f 84 5b 01 00 00 RSP: 0018:ffffc9000321e980 EFLAGS: 00000246 RAX: 1ffff1100b962acf RBX: 0000000000000000 RCX: ffff88802b459dc0 RDX: 0000000000000000 RSI: ffffffff8af9f2a0 RDI: ffffffff8af9f260 RBP: ffffc9000321eab8 R08: ffffffff8a1758a9 R09: fffffbfff2131821 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880600cd000 R13: ffff88802b197940 R14: ffff88805cb15678 R15: dffffc0000000000 batadv_hardif_enable_interface+0x78b/0x9e0 net/batman-adv/hard-interface.c:766 batadv_softif_slave_add+0x75/0xf0 net/batman-adv/soft-interface.c:842 do_set_master net/core/rtnetlink.c:2572 [inline] do_setlink+0xdd3/0x3d80 net/core/rtnetlink.c:2783 __rtnl_newlink net/core/rtnetlink.c:3447 [inline] rtnl_newlink+0x17d6/0x2070 net/core/rtnetlink.c:3569 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5647 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2489 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1337 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x564/0x720 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2071 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f79dd937ffc RSP: 002b:00007fffe0b5a880 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f79de67d620 RCX: 00007f79dd937ffc RDX: 0000000000000028 RSI: 00007f79de67d670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fffe0b5a8d4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f79de67d670 R15: 0000000000000000 </TASK> rcu: rcu_preempt kthread starved for 10551 jiffies! g10333 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:26816 pid: 15 ppid: 2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 </TASK> rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562 Code: a5 37 f7 48 83 e3 08 0f 85 0a 01 00 00 4c 8d 74 24 20 e8 84 1f 3e f7 0f 1f 44 00 00 e8 1a a1 37 f7 0f 00 2d a3 4f bb 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 db 89 81 f7 RSP: 0000:ffffc90000d67b00 EFLAGS: 000002d3 RAX: ffffffff8a48e476 RBX: 0000000000000000 RCX: ffff88813ff68000 RDX: 0000000000000000 RSI: ffffffff8aab2b80 RDI: ffffffff8af9f2c0 RBP: ffffc90000d67b90 R08: ffffffff81870420 R09: ffffed1027fed001 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001acf60 R13: ffff88801f320804 R14: ffffc90000d67b20 R15: dffffc0000000000 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:697 cpuidle_enter_state+0x521/0xef0 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e4/0x670 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x371/0x500 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb </TASK>