rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P682/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=9213, q=683 ncpus=2)
task:kworker/u4:5 state:R running task stack:23984 pid:682 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
preempt_schedule_irq+0xb5/0x140 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+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 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 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc900037b7a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 3ea753f204a5db00
RDX: 0000000000000000 RSI: ffffffff8aaacbc0 RDI: ffffffff8afc6780
RBP: ffffc900037b7b48 R08: dffffc0000000000 R09: 1ffffffff21b46a4
R10: dffffc0000000000 R11: fffffbfff21b46a5 R12: 1ffff920006f6f54
R13: ffffffff8cd2fba0 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
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 10528 jiffies! g9213 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:27088 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5981 Comm: syz.2.19 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3762 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3782 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3837 [inline]
RIP: 0010:__lock_acquire+0x1398/0x7c80 kernel/locking/lockdep.c:5137
Code: b8 eb 83 b5 80 46 86 c8 61 49 0f af c4 48 c1 e8 2d 48 8d 1c c5 60 34 91 90 48 89 d8 48 c1 e8 03 48 89 44 24 38 42 80 3c 00 00 <74> 12 48 89 df e8 7e ba 75 00 49 b8 00 00 00 00 00 fc ff df 48 89
RSP: 0018:ffffc90003577700 EFLAGS: 00000046
RAX: 1ffffffff213e1c3 RBX: ffffffff909f0e18 RCX: ffffffff816720a4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90da3528
RBP: ffffc90003577948 R08: dffffc0000000000 R09: 1ffffffff21b46a5
R10: dffffc0000000000 R11: fffffbfff21b46a6 R12: cc2e8dbae22ca736
R13: ffff888077e5da00 R14: 00000000e22ca736 R15: ffff888077e5e528
FS: 00005555564f3500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000003017a000 CR4: 00000000003506e0
Call Trace:
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
lock_hrtimer_base kernel/time/hrtimer.c:181 [inline]
hrtimer_start_range_ns+0xf3/0x1000 kernel/time/hrtimer.c:1354
posixtimer_rearm+0x135/0x340 kernel/time/posix-timers.c:268
dequeue_signal+0x1ba/0x4b0 kernel/signal.c:706
get_signal+0x551/0x1400 kernel/signal.c:2782
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 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: 0033:0x7fc16fd8ebe9
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:00007ffd6ad711e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fc16ffb5fa0 RCX: 00007fc16fd8ebe9
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fc16fe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc16ffb5fa0 R14: 00007fc16ffb5fa0 R15: 0000000000000004