rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14522/1:b..l P6999/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=69717, q=264 ncpus=2)
task:kworker/u8:25 state:R running task stack:22360 pid:6999 tgid:6999 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 20 b1 bb 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0a 20 e2 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 da 50 72 ff cc 48 8d 3d 37 7a e7
RSP: 0018:ffffc900037672f0 EFLAGS: 00000286
RAX: 8d25a1644d8bf800 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000001ef8cb0b RSI: ffffffff8d97608a RDI: ffffffff8bc083e0
RBP: ffffffff8263495c R08: ffffffff8263495c R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffed1003650038 R12: 0000000000000002
R13: ffffffff8df41aa0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75
kernfs_unlink_sibling+0x110/0x180 fs/kernfs/dir.c:428
__kernfs_remove+0x3d4/0x650 fs/kernfs/dir.c:1519
kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files fs/sysfs/group.c:28 [inline]
sysfs_remove_group+0xfc/0x2f0 fs/sysfs/group.c:328
sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352
device_remove_groups drivers/base/core.c:2843 [inline]
device_remove_attrs+0x208/0x260 drivers/base/core.c:2979
device_del+0x509/0x8e0 drivers/base/core.c:3877
unregister_netdevice_many_notify+0x1ddd/0x2340 net/core/dev.c:12418
unregister_netdevice_many net/core/dev.c:12446 [inline]
default_device_exit_batch+0x964/0x9e0 net/core/dev.c:13038
ops_exit_list net/core/net_namespace.c:205 [inline]
ops_undo_list+0x525/0x990 net/core/net_namespace.c:252
cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:kworker/u8:8 state:R running task stack:24472 pid:14522 tgid:14522 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 20 b1 bb 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0a 20 e2 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 da 50 72 ff cc 48 8d 3d 37 7a e7
RSP: 0018:ffffc900040df840 EFLAGS: 00000282
RAX: e629821233137800 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000d95b78e0 RSI: ffffffff8d97608a RDI: ffffffff8bc083e0
RBP: ffffffff8b227a20 R08: ffffffff8b227a20 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffed10064ebe17 R12: 0000000000000002
R13: ffffffff8df41aa0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:761 [inline]
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline]
batadv_iv_ogm_schedule+0x454/0xf00 net/batman-adv/bat_iv_ogm.c:873
batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: rcu_preempt kthread starved for 10583 jiffies! g69717 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:26528 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_raw_spin_lock_irqsave+0x4f/0x60 kernel/locking/spinlock.c:162
Code: 8d 7e 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 74 24 10 e8 80 b7 41 f6 48 83 c4 08 4c 89 f7 e8 04 58 42 f6 48 89 d8 <5b> 41 5e e9 74 0a b4 f5 cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc90000a08bc0 EFLAGS: 00000046
RAX: 0000000000000002 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000a08b40
RBP: ffff88802b090000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141168 R12: dffffc0000000000
R13: ffff888033410400 R14: ffff88802b090a50 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 00000000532af000 CR4: 0000000000350ef0
Call Trace:
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4106
signal_wake_up_state+0xb5/0x120 kernel/signal.c:734
posixtimer_send_sigqueue+0x404/0xa70 kernel/signal.c:2080
posix_timer_queue_signal kernel/time/posix-timers.c:364 [inline]
posix_timer_fn+0x121/0x1c0 kernel/time/posix-timers.c:379
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:sched_core_balance+0xe3/0xe10 kernel/sched/core.c:6284
Code: 03 00 00 48 c7 c2 a0 99 6a 8b e8 68 73 0b 00 4c 89 74 24 50 e9 b1 0c 00 00 4c 89 f7 e8 a6 72 c9 09 e8 51 fa 35 00 fb 83 fb 08 <0f> 83 84 0c 00 00 48 89 5c 24 68 4c 8d 34 dd d0 fd 9a 8d 4c 89 f0
RSP: 0018:ffffc90000197ac0 EFLAGS: 00000297
RAX: 00000000018c6473 RBX: 0000000000000001 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8d792134 RDI: ffffffff8bc083e0
RBP: ffffc90000197c10 R08: ffffffff8f822577 R09: 1ffffffff1f044ae
R10: dffffc0000000000 R11: fffffbfff1f044af R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880b873a900 R15: 0000000000000001
do_balance_callbacks kernel/sched/core.c:4901 [inline]
__balance_callbacks kernel/sched/core.c:4955 [inline]
finish_lock_switch kernel/sched/core.c:4994 [inline]
finish_task_switch+0x404/0x940 kernel/sched/core.c:5112
context_switch kernel/sched/core.c:5259 [inline]
__schedule+0x14a3/0x4fd0 kernel/sched/core.c:6863
schedule_idle+0x52/0x90 kernel/sched/core.c:6986
do_idle+0x472/0x4d0 kernel/sched/idle.c:360
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147