rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5138/2:b..l P3461/1:b..l rcu: (detected by 1, t=10503 jiffies, g=11417, q=629 ncpus=2) task:kworker/u4:9 state:R running task stack:24048 pid:3461 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet 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:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000cf478a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 805d9b49b39ddf00 RDX: 0000000000000000 RSI: ffffffff8acada80 RDI: ffffffff8b1c80e0 RBP: ffffc9000cf479a8 R08: dffffc0000000000 R09: 1ffffffff2237ca0 R10: dffffc0000000000 R11: fffffbfff2237ca1 R12: 1ffff920019e8f20 R13: ffffffff8d131fe0 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:753 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:824 [inline] batadv_iv_ogm_schedule+0x40b/0xf10 net/batman-adv/bat_iv_ogm.c:867 batadv_iv_send_outstanding_bat_ogm_packet+0x733/0x850 net/batman-adv/bat_iv_ogm.c:1711 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 task:udevd state:R running task stack:25000 pid:5138 ppid:1 flags:0x00004002 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:seqcount_lockdep_reader_access+0x199/0x1d0 include/linux/seqlock.h:105 Code: ff 4d 85 ed 75 16 e8 96 2f 8a ff eb 15 e8 8f 2f 8a ff e8 2a 28 87 08 4d 85 ed 74 ea e8 80 2f 8a ff fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 43 c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc90003317440 EFLAGS: 00000293 RAX: ffffffff81fce3a0 RBX: 0000000000000000 RCX: ffff88807d8bbc00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900033174e8 R08: ffffffff911be53f R09: 1ffffffff2237ca7 R10: dffffc0000000000 R11: fffffbfff2237ca8 R12: dffffc0000000000 R13: 0000000000000200 R14: ffffffff81fcc28f R15: 1ffff92000662e88 read_seqbegin include/linux/seqlock.h:893 [inline] read_seqbegin_or_lock include/linux/seqlock.h:1187 [inline] prepend_path+0x29f/0x960 fs/d_path.c:171 d_absolute_path+0xa2/0x140 fs/d_path.c:234 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x2d9/0x5d0 security/tomoyo/realpath.c:271 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x224/0x460 security/tomoyo/file.c:771 security_file_open+0x62/0xa0 security/security.c:2854 do_dentry_open+0x380/0x1500 fs/open.c:916 do_open fs/namei.c:3640 [inline] path_openat+0x27f1/0x3230 fs/namei.c:3797 do_filp_open+0x1f5/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0a0f315c3a RSP: 002b:00007ffffecae788 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055b964e6e710 RCX: 00007f0a0f315c3a RDX: 0000000000090800 RSI: 000055b964de13f0 RDI: 00000000ffffff9c RBP: 000055b964de13f0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000206 R12: 000055b964ded7b0 R13: 00000000000000ff R14: 000055b95f1e7be0 R15: 00007ffffecaea10 rcu: rcu_preempt kthread starved for 10286 jiffies! g11417 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:I stack:27656 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 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:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: 18 23 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 43 32 44 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c2 RAX: 9a65eb4f57a1c900 RBX: ffffffff8162a570 RCX: 9a65eb4f57a1c900 RDX: 0000000000000001 RSI: ffffffff8acac900 RDI: ffffffff8b1c80e0 RBP: ffffffff8ce07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65 R10: dffffc0000000000 R11: ffffed10171c6d66 R12: 1ffffffff19d2688 R13: 1ffffffff19c0fbc R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007eff0b8c2fb3 CR3: 000000006172c000 CR4: 00000000003506f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1f0/0x4e0 kernel/sched/idle.c:282 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