rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=bff4/0/0x1 softirq=89177/89180 fqs=302 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17958/1:b..l P63/1:b..l rcu: (detected by 1, t=10502 jiffies, g=74313, q=211 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc2-syzkaller-00257-gb5c6891b2c5b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:135 [inline] RIP: 0010:cpumask_check include/linux/cpumask.h:142 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:587 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1143 [inline] RIP: 0010:trace_hrtimer_expire_entry include/trace/events/timer.h:259 [inline] RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1758 [inline] RIP: 0010:__hrtimer_run_queues+0x493/0xd40 kernel/time/hrtimer.c:1825 Code: df e8 31 5c 7a 00 4c 8b 2b 4c 89 ff 48 8b b4 24 b0 00 00 00 e8 be 64 7a 0a 0f 1f 44 00 00 e8 a4 ad 12 00 65 8b 1d d1 03 b5 11 07 00 00 00 89 de e8 d1 b1 12 00 83 fb 07 0f 87 db 02 00 00 e8 RSP: 0018:ffffc90000007d40 EFLAGS: 00000006 RAX: ffffffff81b00c5c RBX: 0000000000000000 RCX: ffffffff8ea96580 RDX: 0000000000010000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffc90000007ea0 R08: ffff8880b86276c3 R09: 1ffff110170c4ed8 R10: dffffc0000000000 R11: ffffed10170c4ed9 R12: 1ffff110170c4f03 R13: ffffffff8a1df570 R14: ffff888032c2a340 R15: ffff8880b86276c0 FS: 0000000000000000(0000) GS:ffff888124fcf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f08bff0f270 CR3: 000000006d298000 CR4: 00000000003526f0 Call Trace: hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 6f 20 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8ea07d60 EFLAGS: 000002c2 RAX: fc9ab8ef19eabd00 RBX: ffffffff8197267e RCX: ffffffff8c27c93c RDX: 0000000000000001 RSI: ffffffff8e63579e RDI: ffffffff8ca0e160 RBP: ffffffff8ea07eb8 R08: ffff8880b8632b5b R09: 1ffff110170c656b R10: dffffc0000000000 R11: ffffed10170c656c R12: 1ffffffff1d40fc6 R13: 1ffffffff1d52cb0 R14: 0000000000000000 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x22e/0x5d0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 rest_init+0x2dc/0x300 init/main.c:743 start_kernel+0x484/0x510 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494 common_startup_64+0x13e/0x147 task:kworker/u8:4 state:R running task stack:21032 pid:63 tgid:63 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline] RIP: 0010:lock_acquire+0x9d/0x2f0 kernel/locking/lockdep.c:5842 Code: c0 0e 00 0f 84 e6 00 00 00 48 8b 74 24 70 48 89 df e8 07 d7 8b 00 83 3d 90 84 c0 0e 00 0f 84 ef 00 00 00 65 8b 05 73 e6 c6 11 <85> c0 0f 85 e0 00 00 00 65 48 8b 04 25 08 10 65 93 83 b8 ec 0a 00 RSP: 0018:ffffc900015578a0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff8ed3df20 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff8bec3777 RDI: 1ffffffff1da7be4 RBP: ffffffff93651020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: dffffc0000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:762 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline] batadv_iv_ogm_schedule+0x447/0x10b0 net/batman-adv/bat_iv_ogm.c:876 batadv_iv_send_outstanding_bat_ogm_packet+0x695/0x7a0 net/batman-adv/bat_iv_ogm.c:1720 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:modprobe state:R running task stack:23624 pid:17958 tgid:17958 ppid:36 task_flags:0x400000 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 54 ba b5 0c 48 89 de 5b e9 93 3b 5c 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 10 65 93 65 8b 15 18 56 RSP: 0000:ffffc9000c5afb98 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000000 RDX: ffff88803164da00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000c5afc70 R08: ffffffff821003bf R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88803164da00 R13: dffffc0000000000 R14: ffffffff93651020 R15: dffffc0000000000 count_memcg_events_mm include/linux/memcontrol.h:-1 [inline] count_memcg_event_mm+0x18f/0x440 include/linux/memcontrol.h:996 mm_account_fault mm/memory.c:6174 [inline] handle_mm_fault+0x160c/0x1aa0 mm/memory.c:6335 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x45b/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x559ac0aac070 RSP: 002b:00007ffeecaed560 EFLAGS: 00010206 RAX: 000000008767a21c RBX: 0000000000000000 RCX: 00007ffeecaed590 RDX: 00007fb18764eb5d RSI: 00007fb18767a848 RDI: 00007fb18767a2a0 RBP: 0000000000000000 R08: 0000000000000000 R09: 9a61b25834c3fd64 R10: 000000000000004f R11: 0000000000000246 R12: 0000559ac0aac070 R13: 00007ffeecaed560 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 9092 jiffies! g74313 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:26952 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.15.0-rc2-syzkaller-00257-gb5c6891b2c5b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 6f 20 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197dc0 EFLAGS: 000002c2 RAX: 6464278d7735ff00 RBX: ffffffff8197267e RCX: ffffffff8c27c93c RDX: 0000000000000001 RSI: ffffffff8e63579e RDI: ffffffff8ca0e160 RBP: ffffc90000197f20 R08: ffff8880b8732b5b R09: 1ffff110170e656b R10: dffffc0000000000 R11: ffffed10170e656c R12: 1ffff92000032fd2 R13: 1ffff11003ad8b40 R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559ac0aac070 CR3: 000000005ad94000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x22e/0x5d0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 start_secondary+0xfe/0x100 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147