rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4328/1:b..l (detected by 1, t=10502 jiffies, g=44113, q=159 ncpus=2) task:kworker/u4:6 state:R running task stack:23152 pid:4328 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 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:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:409 [inline] RIP: 0010:batadv_nc_worker+0x175/0x600 net/batman-adv/network-coding.c:719 Code: 05 a7 6f 14 04 01 48 c7 c7 c0 05 ae 8b be 19 03 00 00 48 c7 c2 00 06 ae 8b e8 d7 d6 6d f7 48 89 e8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 ef e8 21 6a dc f7 48 8b 6d 00 48 85 ed 0f 94 c0 48 81 RSP: 0018:ffffc900045c7be0 EFLAGS: 00000246 RAX: 1ffff1100b1c230f RBX: 0000000000000001 RCX: ffff88802b5dbb80 RDX: 0000000000000000 RSI: ffffffff8adf1300 RDI: ffffffff8adf12c0 RBP: ffff888058e11878 R08: dffffc0000000000 R09: 1ffffffff215f248 R10: dffffc0000000000 R11: fffffbfff215f249 R12: dffffc0000000000 R13: ffffffff89f716be R14: ffff888058e08c80 R15: 000000000000030f process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 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 9623 jiffies! g44113 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:27760 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 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+0x303/0x1340 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: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 77 a3 9b f7 e9 44 ff ff ff e8 3d 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d a7 ca 4e 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6 RAX: 8e8e4f09b5de9600 RBX: ffffffff8a37e307 RCX: 8e8e4f09b5de9600 RDX: 0000000000000001 RSI: ffffffff8a8c1120 RDI: ffffffff8adf1320 RBP: ffffc90000177f20 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff888017739dc0 R15: 1ffff9200002efc8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea645486c8 CR3: 000000001d29e000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x250/0x680 kernel/sched/idle.c:323 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:422 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xcf/0xdb