rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4310/1:b..l (detected by 1, t=10502 jiffies, g=8201, q=2) task:kworker/u4:6 state:R running task stack:26976 pid: 4310 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_mcast_mla_update Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x7b/0x290 mm/kasan/generic.c:189 Code: 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 4d 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41 80 39 00 <0f> 85 c1 01 00 00 49 ff c1 48 ff c3 75 ee e9 1c 01 00 00 44 89 cb RSP: 0018:ffffc900034bfaa0 EFLAGS: 00000246 RAX: ffffffff897da101 RBX: ffffffffffffffff RCX: ffffffff897da18f RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880793c4664 RBP: ffffc900034bfc30 R08: dffffc0000000000 R09: ffffed100f2788cc R10: ffffed100f2788cd R11: 1ffff1100f2788cc R12: 0000000000000000 R13: ffff88807c3cb908 R14: 0000000000000001 R15: dffffc0000000001 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] batadv_mcast_mla_rtr_flags_softif_get_ipv6 net/batman-adv/multicast.c:137 [inline] batadv_mcast_mla_rtr_flags_softif_get net/batman-adv/multicast.c:174 [inline] batadv_mcast_mla_rtr_flags_get net/batman-adv/multicast.c:232 [inline] batadv_mcast_mla_flags_get net/batman-adv/multicast.c:257 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:876 [inline] batadv_mcast_mla_update+0x3cf/0x3110 net/batman-adv/multicast.c:915 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10528 jiffies! g8201 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:27008 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 4475 Comm: syz.1.54 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:raw_spin_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1339 Code: c0 48 8b 3c 24 e8 2d bd 68 00 eb b5 66 2e 0f 1f 84 00 00 00 00 00 90 41 57 41 56 53 eb 11 e8 14 46 5f 08 e8 2f 73 2a 00 fb 5b <41> 5e 41 5f c3 49 be 00 00 00 00 00 fc ff df 49 89 ff 48 8d 9f 58 RSP: 0018:ffffc900034ff848 EFLAGS: 00000286 RAX: 344f45179f727200 RBX: ffff8880b913a340 RCX: 344f45179f727200 RDX: dffffc0000000000 RSI: ffffffff8a0b18a0 RDI: ffffffff8a59a880 RBP: ffffc900034ffa40 R08: dffffc0000000000 R09: ffffed1017207469 R10: ffffed1017207469 R11: 1ffff11017207468 R12: 1ffff110172275ab R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff8880b913b088 __schedule+0x1464/0x4390 kernel/sched/core.c:6401 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x22d/0x440 kernel/futex/core.c:2863 futex_wait+0x202/0x5c0 kernel/futex/core.c:2964 do_futex+0xd1c/0x1240 kernel/futex/core.c:3982 __do_sys_futex kernel/futex/core.c:4059 [inline] __se_sys_futex+0x3a3/0x430 kernel/futex/core.c:4040 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff93f579fc9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff93d7e10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007ff93f7d0fa8 RCX: 00007ff93f579fc9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff93f7d0fa8 RBP: 00007ff93f7d0fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff93f7d1038 R14: 00007ffda659c180 R15: 00007ffda659c268 sched: RT throttling activated