rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4627/1:b..l (detected by 0, t=10502 jiffies, g=26693, q=37 ncpus=2) task:kworker/u4:15 state:R running task stack:23104 pid:4627 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 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+0x183/0x600 net/batman-adv/network-coding.c:719 Code: 19 03 00 00 48 c7 c2 20 1c 8d 8b e8 c7 06 8a f7 48 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 61 bc f8 f7 48 8b 6d 00 <48> 85 ed 0f 94 c0 48 81 c5 38 fe ff ff 0f 94 c1 08 c1 74 07 e8 84 RSP: 0018:ffffc90004d4fbe0 EFLAGS: 00000246 RAX: 1ffff1100ecdc1c8 RBX: 0000000000000001 RCX: ffff88807cb41dc0 RDX: 0000000000000000 RSI: ffffffff8abf1340 RDI: ffffffff8abf1300 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff2117049 R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: dffffc0000000000 R13: ffffffff89d9921e R14: ffff88807bc38c80 R15: 00000000000001c8 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 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 9853 jiffies! g26693 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:27840 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 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: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.141-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:736 Code: 48 89 df e8 47 d4 b8 f7 e9 4c ff ff ff e8 bd 15 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 17 24 4d 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: 0000:ffffffff8c607d88 EFLAGS: 000002c6 RAX: 97c97881f8aefb00 RBX: ffffffff8a197f77 RCX: 97c97881f8aefb00 RDX: 0000000000000001 RSI: ffffffff8a6bffe0 RDI: ffffffff8abf1360 RBP: ffffffff8c607ec0 R08: dffffc0000000000 R09: ffffed10171c6af6 R10: ffffed10171c6af6 R11: 1ffff110171c6af5 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8c6bc680 R15: 1ffffffff1bfd0f6 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe7d666f963 CR3: 0000000076244000 CR4: 00000000003526f0 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:191 [inline] do_idle+0x1fc/0x570 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 rest_init+0x2dc/0x300 init/main.c:733 arch_call_rest_init+0xa/0xa init/main.c:893 start_kernel+0x490/0x539 init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb