rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P19343/1:b..l rcu: (detected by 1, t=10502 jiffies, g=146389, q=304 ncpus=2) task:kworker/u4:15 state:R running task stack:22072 pid:19343 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 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:lockdep_enabled kernel/locking/lockdep.c:119 [inline] RIP: 0010:lock_acquire+0xf8/0x410 kernel/locking/lockdep.c:5730 Code: 84 18 02 00 00 48 c7 c0 9c c9 4a 8e 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 07 02 00 00 83 3d 0a c8 e3 0c 00 0f 84 f1 00 00 00 <65> 8b 05 49 88 9b 7e 85 c0 0f 85 2e 01 00 00 65 4c 8b 35 51 b8 9c RSP: 0018:ffffc900045379c0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: e78b2ef252469800 RDX: 0000000000000000 RSI: ffffffff8afc72a0 RDI: ffffffff8afc7260 RBP: ffffc90004537ad8 R08: ffffffff8e4a94ef R09: 1ffffffff1c9529d R10: dffffc0000000000 R11: fffffbfff1c9529e R12: 1ffff920008a6f44 R13: ffffffff8cd2fe20 R14: 0000000000000001 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] batadv_nc_process_nc_paths+0xdb/0x390 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x52b/0x610 net/batman-adv/network-coding.c:735 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 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 10502 jiffies! g146389 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:27048 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 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: 1 PID: 20004 Comm: syz.1.3781 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0xddf/0x1130 kernel/smp.c:855 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 da d6 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 d3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 f9 d2 RSP: 0018:ffffc9000cbcf680 EFLAGS: 00000293 RAX: ffffffff817abd47 RBX: 1ffff110171c87d9 RCX: ffff888025c3da00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000cbcf800 R08: ffffffff90da7507 R09: 1ffffffff21b4ea0 R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: ffff8880b8e43ec8 R13: dffffc0000000000 R14: ffff8880b8f3d588 R15: 0000000000000000 FS: 000055558bb95500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c44bea2 CR3: 000000006878b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 000000000000000c DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2222 [inline] text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432 text_poke_bp+0xb0/0xf0 arch/x86/kernel/alternative.c:2659 __static_call_transform+0x3a4/0x570 arch/x86/kernel/static_call.c:111 arch_static_call_transform+0x5f/0xc0 arch/x86/kernel/static_call.c:163 __static_call_update+0xe1/0x5c0 kernel/static_call_inline.c:147 tracepoint_update_call kernel/tracepoint.c:317 [inline] tracepoint_remove_func kernel/tracepoint.c:441 [inline] tracepoint_probe_unregister+0x8a0/0x930 kernel/tracepoint.c:551 bpf_raw_tp_link_release+0x63/0x90 kernel/bpf/syscall.c:3375 bpf_link_free+0x131/0x310 kernel/bpf/syscall.c:2918 bpf_link_put_direct kernel/bpf/syscall.c:2958 [inline] bpf_link_release+0x6e/0x80 kernel/bpf/syscall.c:2965 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f550fd8eba9 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:00007ffec5eadbb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f550ffd7da0 RCX: 00007f550fd8eba9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f550ffd7da0 R08: 0000000000000190 R09: 00000016c5eadeaf R10: 00007f550ffd7cb0 R11: 0000000000000246 R12: 000000000014e2e9 R13: 00007f550ffd6180 R14: ffffffffffffffff R15: 00007ffec5eadcd0