rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11578/1:b..l rcu: (detected by 0, t=10503 jiffies, g=101105, q=85 ncpus=2) task:kworker/u4:16 state:R running task stack:22632 pid:11578 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215 Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 2c cd 03 0d 48 89 de 5b e9 93 57 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 00 a1 7c 7e 65 8b 15 01 a1 7c 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc90005647b58 EFLAGS: 00000202 RAX: ffffffff8a4bc375 RBX: 0000000000000001 RCX: f64713353d069a00 RDX: ffff888031261e00 RSI: ffffffff8b1c81c0 RDI: ffffffff8b1c8180 RBP: ffff888078680980 R08: dffffc0000000000 R09: 1ffffffff2237ea0 R10: dffffc0000000000 R11: fffffbfff2237ea1 R12: dffffc0000000000 R13: ffffffff8a4bc332 R14: ffff88805d064c80 R15: 0000000000000130 rcu_read_lock include/linux/rcupdate.h:787 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x115/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: rcu_preempt kthread starved for 10526 jiffies! g101105 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:26568 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:tick_nohz_idle_enter+0x1c6/0x260 kernel/time/tick-sched.c:1175 Code: 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 92 00 00 00 80 0b 01 48 89 df e8 a8 00 00 00 e8 43 dc 12 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 48 RSP: 0018:ffffffff8ce07d00 EFLAGS: 00000286 RAX: 8a4a336e6a0fa100 RBX: ffff8880b8e2c040 RCX: 8a4a336e6a0fa100 RDX: dffffc0000000000 RSI: ffffffff8acac900 RDI: ffffffff8b1c81e0 RBP: ffffffff8ce07d90 R08: ffffffff8e8adfaf R09: 1ffffffff1d15bf5 R10: dffffc0000000000 R11: fffffbfff1d15bf6 R12: 1ffffffff19c0fa0 R13: 1ffffffff19c0fbc R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c24d0c1 CR3: 0000000064517000 CR4: 00000000003506f0 Call Trace: do_idle+0x9a/0x4e0 kernel/sched/idle.c:256 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 rest_init+0x2e2/0x300 init/main.c:744 arch_call_rest_init+0xe/0x10 init/main.c:841 start_kernel+0x459/0x4e0 init/main.c:1086 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b