rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4381/1:b..l (detected by 1, t=10503 jiffies, g=10105, q=161 ncpus=2) task:kworker/u4:5 state:R running task stack:26512 pid:4381 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:kasan_check_range+0x1b0/0x290 mm/kasan/generic.c:-1 Code: f3 4d 01 f3 49 89 df 49 8d 5f 07 4d 85 ff 49 0f 49 df 48 83 e3 f8 49 29 df 74 0e 41 80 3b 00 75 69 49 ff c3 49 ff cf 75 f2 5b <41> 5c 41 5e 41 5f 5d c3 45 84 ff 0f 85 91 00 00 00 41 f7 c7 00 ff RSP: 0018:ffffc900033078f8 EFLAGS: 00000256 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8163f3f4 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e200f68 RBP: ffffc90003307a28 R08: ffffffff8e200f6f R09: 1ffffffff1c401ed R10: dffffc0000000000 R11: fffffbfff1c401ee R12: dffffc0000000001 R13: 1ffff92000660f30 R14: 1ffffffff1c401ed R15: 0000000000000001 instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:444 [inline] cpu_online include/linux/cpumask.h:1030 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xd4/0x4a0 kernel/locking/lockdep.c:5633 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:760 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:840 [inline] batadv_iv_ogm_schedule+0x458/0x1080 net/batman-adv/bat_iv_ogm.c:899 batadv_iv_send_outstanding_bat_ogm_packet+0x6bb/0x7d0 net/batman-adv/bat_iv_ogm.c:1796 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10532 jiffies! g10105 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:27120 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 4496 Comm: syz.1.18 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 0e 82 2f f7 48 89 df e8 76 49 30 f7 e8 01 95 53 f7 fb bf 01 00 00 00 66 cb 23 f7 65 8b 05 67 7c cd 75 85 c0 74 02 5b c3 e8 74 90 cb RSP: 0018:ffffc900035b7b98 EFLAGS: 00000282 RAX: bed2f6201f9cda00 RBX: ffff88805b5240c0 RCX: bed2f6201f9cda00 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffff88805b5240c3 R09: 1ffff1100b6a4818 R10: dffffc0000000000 R11: ffffed100b6a4819 R12: 0000000000000021 R13: ffff88805b524558 R14: dffffc0000000000 R15: 000000001c000004 FS: 0000555594fa7500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 0000000075379000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x114a/0x1340 kernel/signal.c:2875 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2672b9ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe15f530e8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f2672e15fa0 RCX: 00007f2672b9ce59 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f2672c32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2672e15fac R14: 00007f2672e15fa0 R15: 00007f2672e15fa0 sched: RT throttling activated