rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1237/1:b..l P157/1:b..l
(detected by 0, t=10502 jiffies, g=21661, q=115)
task:kworker/u4:3 state:R running task stack:24616 pid: 157 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780
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+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 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 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90002037a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: e655a0fc70cd6600
RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59a740
RBP: ffffc90002037b58 R08: dffffc0000000000 R09: fffffbfff1ff3619
R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: ffffffff8c11bfa0
R13: 1ffff92000406f54 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
rcu_read_lock include/linux/rcupdate.h:739 [inline]
batadv_nc_process_nc_paths+0xb2/0x350 net/batman-adv/network-coding.c:691
batadv_nc_worker+0x3e5/0x5c0 net/batman-adv/network-coding.c:732
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
task:kworker/u4:4 state:R running task stack:22376 pid: 1237 ppid: 2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780
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:batadv_hardif_get_by_netdev+0x13e/0x390 net/batman-adv/hard-interface.c:70
Code: f8 4c 8b 35 74 34 d5 0c 49 81 fe a0 65 4a 96 0f 84 8d 01 00 00 48 89 5c 24 10 4d 8d 66 18 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 e7 e8 d8 08 48 f8 49 39 1c 24 74 0a e8 bd 90 02 f8 e9
RSP: 0018:ffffc90004d27360 EFLAGS: 00000246
RAX: 1ffff1100c1ca703 RBX: ffff88801d604000 RCX: ffff888021da1dc0
RDX: 0000000000000000 RSI: ffffffff8a59a720 RDI: ffffffff8a59a6e0
RBP: ffffc90004d27418 R08: dffffc0000000000 R09: fffffbfff1ff3619
R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: ffff888060e53818
R13: dffffc0000000000 R14: ffff888060e53800 R15: dffffc0000000000
batadv_hard_if_event+0x7e/0x17e0 net/batman-adv/hard-interface.c:955
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
dev_close_many+0x28d/0x400 net/core/dev.c:1650
unregister_netdevice_many+0x472/0x18f0 net/core/dev.c:11110
unregister_netdevice_queue+0x31c/0x360 net/core/dev.c:11067
unregister_netdevice include/linux/netdevice.h:3020 [inline]
nsim_destroy+0x49/0x150 drivers/net/netdevsim/netdev.c:382
__nsim_dev_port_del+0x155/0x1c0 drivers/net/netdevsim/dev.c:1349
nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1362 [inline]
nsim_dev_reload_destroy+0x16c/0x240 drivers/net/netdevsim/dev.c:1561
nsim_dev_reload_down+0xf9/0x160 drivers/net/netdevsim/dev.c:883
devlink_reload+0x265/0x770 net/core/devlink.c:3963
devlink_pernet_pre_exit+0x19d/0x300 net/core/devlink.c:11543
ops_pre_exit_list net/core/net_namespace.c:162 [inline]
cleanup_net+0x57b/0xb80 net/core/net_namespace.c:615
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 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 10572 jiffies! g21661 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:27872 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 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:
NMI backtrace for cpu 0
CPU: 0 PID: 6945 Comm: syz.0.583 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3932 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1690 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/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: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 9a b1 f7 48 89 df e8 56 6f b2 f7 e8 a1 13 d3 f7 fb bf 01 00 00 00 86 93 a6 f7 65 8b 05 27 a3 57 76 85 c0 74 02 5b c3 e8 d4 ad 55
RSP: 0018:ffffc900031dfbc0 EFLAGS: 00000282
RAX: 5beb3c2637a9f900 RBX: ffff88807c274a00 RCX: 5beb3c2637a9f900
RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100f84e941
R10: ffffed100f84e941 R11: 1ffff1100f84e940 R12: ffff88807c274a00
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:413 [inline]
get_signal+0x11d6/0x12c0 kernel/signal.c:2903
arch_do_signal_or_restart+0xc1/0x1300 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+0xb1/0x140 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: 0033:0x7fe366daf927
Code: ff ff 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
RSP: 002b:00007fe364c170e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fe366fd6fa8 RCX: 00007fe366daf929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe366fd6fa8
RBP: 00007fe366fd6fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe366fd6fac
R13: 0000000000000000 R14: 00007fff0c2fcf80 R15: 00007fff0c2fd068