rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/1:b..l
(detected by 1, t=10502 jiffies, g=54409, q=21)
task:kworker/u4:0 state:R running task stack:21464 pid: 9 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90000ce7900 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 23724defd35b4d00
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f780
RBP: ffffc90000ce7a20 R08: dffffc0000000000 R09: 1ffffffff203a218
R10: dffffc0000000000 R11: fffffbfff203a219 R12: ffffffff8c31eaa0
R13: 1ffff9200019cf2c R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline]
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:825 [inline]
batadv_iv_ogm_schedule+0x432/0xec0 net/batman-adv/bat_iv_ogm.c:868
batadv_iv_send_outstanding_bat_ogm_packet+0x72f/0x840 net/batman-adv/bat_iv_ogm.c:1712
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10528 jiffies! g54409 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:27120 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
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: 13124 Comm: syz.7.1602 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ksoftirqd_running kernel/softirq.c:93 [inline]
RIP: 0010:invoke_softirq kernel/softirq.c:440 [inline]
RIP: 0010:__irq_exit_rcu+0x106/0x230 kernel/softirq.c:659
Code: 44 8b 35 bd 4d ba 7e 48 c7 c7 60 0f 2a 8a e8 a1 ae 72 08 65 48 8b 3d 41 2b b9 7e 41 f6 c6 41 0f 95 c0 48 85 ff 0f 94 c1 08 c1 <75> 27 4c 8d 77 18 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85
RSP: 0018:ffffc90000007f40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88804aef8000 RCX: 9689b18972d49300
RDX: 1ffffffff1e1cc00 RSI: ffffffff8a2a0f60 RDI: ffff88813fe29dc0
RBP: ffffc90000007fe0 R08: ffffffff8f0e6008 R09: ffffffff8f0e6018
R10: ffffffff8f0e6010 R11: ffffffff8f0e6003 R12: dffffc0000000000
R13: 0000000000000000 R14: 000000000000018a R15: 1ffff92000000fe8
FS: 00007f402ddd26c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e1c2fbdac CR3: 000000007cc6e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e 2c 98 f7 48 89 df e8 86 04 99 f7 e8 11 f3 b9 f7 fb bf 01 00 00 00 06 0b 8d f7 65 8b 05 87 17 3d 76 85 c0 74 02 5b c3 e8 d4 24 3b
RSP: 0018:ffffc9000376fbc0 EFLAGS: 00000282
RAX: 9689b18972d49300 RBX: ffff8880794c8000 RCX: 9689b18972d49300
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff8880794c8003 R09: 1ffff1100f299000
R10: dffffc0000000000 R11: ffffed100f299001 R12: ffff8880794c8000
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11d6/0x12c0 kernel/signal.c:2903
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f402fb76eb7
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f402ddd2028 EFLAGS: 00000246
RAX: 0000000000000113 RBX: 00007f402fdf1fa0 RCX: 00007f402fb76eb9
RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f402fbe4c1f R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f402fdf2038 R14: 00007f402fdf1fa0 R15: 00007ffe118c5448