rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P948/1:b..l P9366/1:b..l rcu: (detected by 1, t=10502 jiffies, g=44385, q=636 ncpus=2) task:syz-executor state:R running task stack:20784 pid:9366 tgid:9366 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 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:unwind_get_return_address+0x0/0xc0 arch/x86/kernel/unwind_orc.c:365 Code: b6 00 48 8d 7c 24 40 8b 74 24 14 e9 dd fe ff ff e8 c5 3d 47 0a 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 53 48 89 fb 49 be 00 00 00 00 00 fc ff RSP: 0018:ffffc9000385f538 EFLAGS: 00000293 RAX: ffffffff81376b8f RBX: ffffffff81e7a5e6 RCX: ffff888022d50000 RDX: 0000000000000000 RSI: 0000000080000000 RDI: ffffc9000385f540 RBP: ffffc9000385f5d0 R08: ffffffff814125c5 R09: ffffffff814120bf R10: 0000000000000003 R11: ffff888022d50000 R12: ffff888022d50000 R13: ffffffff817f29e0 R14: ffffc9000385f620 R15: ffffc9000385f540 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0xd19/0xea0 mm/page_alloc.c:2608 vfree+0x186/0x2e0 mm/vmalloc.c:3364 kcov_put kernel/kcov.c:429 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:525 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:222 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x1695/0x1730 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb04e1749fc RSP: 002b:00007ffdde486d80 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007fb04e1749fc RDX: 0000000000000028 RSI: 00007ffdde486e70 RDI: 00000000000000f9 RBP: 00007ffdde486dfc R08: 0000000000000000 R09: 0079746972756365 R10: 00007fb04e2d17e0 R11: 0000000000000246 R12: 00007ffdde486e70 R13: 0000000000000bb8 R14: 000000000008e03b R15: 000000000008dc6a task:kworker/u8:5 state:R running task stack:20600 pid:948 tgid:948 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5763 Code: 2b 00 74 08 4c 89 f7 e8 6a e6 87 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003f67860 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920007ecf18 RCX: 890697bf5618fd00 RDX: dffffc0000000000 RSI: ffffffff8bcae720 RDI: ffffffff8c1fcba0 RBP: ffffc90003f679a8 R08: ffffffff92fcd807 R09: 1ffffffff25f9b00 R10: dffffc0000000000 R11: fffffbfff25f9b01 R12: 1ffff920007ecf14 R13: dffffc0000000000 R14: ffffc90003f678c0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:825 [inline] batadv_iv_ogm_schedule+0x43f/0x1090 net/batman-adv/bat_iv_ogm.c:868 batadv_iv_send_outstanding_bat_ogm_packet+0x6fe/0x810 net/batman-adv/bat_iv_ogm.c:1712 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10572 jiffies! g44385 f0x0 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:26448 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111