rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4288/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=33005, q=414 ncpus=2)
task:kworker/u8:12 state:R running task stack:24280 pid:4288 tgid:4288 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6866
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7193
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 c0 2a c8 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 da b8 27 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ff 08 cb 09 cc 48 8d 3d e7 eb 28
RSP: 0018:ffffc9000d99ecf8 EFLAGS: 00000282
RAX: eef0c0ed6ea4f200 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000001c1f447c RSI: ffffffff8dc957d2 RDI: ffffffff8be250e0
RBP: ffffffff81743d85 R08: ffffffff81743d85 R09: ffffffff8e33f2a0
R10: ffffc9000d99ee58 R11: ffffffff81acf420 R12: 0000000000000002
R13: ffffffff8e33f2a0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:302 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1166 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6785
skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1107
skb_release_all net/core/skbuff.c:1182 [inline]
__kfree_skb net/core/skbuff.c:1196 [inline]
consume_skb+0x9e/0xf0 net/core/skbuff.c:1428
netlink_broadcast_filtered+0xec7/0x1000 net/netlink/af_netlink.c:1535
nlmsg_multicast_filtered include/net/netlink.h:1165 [inline]
nlmsg_multicast include/net/netlink.h:1184 [inline]
nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593
__ip_mc_dec_group+0x3fa/0x670 net/ipv4/igmp.c:1778
inetdev_event+0x297/0x15b0 net/ipv4/devinet.c:1641
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2269 [inline]
call_netdevice_notifiers net/core/dev.c:2283 [inline]
netif_close_many+0x29c/0x410 net/core/dev.c:1785
unregister_netdevice_many_notify+0xb50/0x2340 net/core/dev.c:12372
unregister_netdevice_many net/core/dev.c:12465 [inline]
default_device_exit_batch+0x964/0x9e0 net/core/dev.c:13057
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+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x389/0x480 kernel/kthread.c:467
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 10546 jiffies! g33005 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:28248 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
kthread+0x389/0x480 kernel/kthread.c:467
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:
CPU: 0 UID: 0 PID: 11873 Comm: syz.0.2868 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:syscall_enter_from_user_mode_work include/linux/entry-common.h:77 [inline]
RIP: 0010:syscall_enter_from_user_mode include/linux/entry-common.h:109 [inline]
RIP: 0010:do_syscall_64+0xb5/0xf80 arch/x86/entry/syscall_64.c:90
Code: 00 48 8b 7d 08 48 89 7b 08 e8 27 82 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 b7 e3 62 f6 90 90 e8 60 e3 62 f6 fb 49 8b 57 08 c2 3f 74 0e 4c 89 f7 4c 89 ee e8 db fc 44 f6 49 89 c4 90 90 41
RSP: 0018:ffffc90004397ef0 EFLAGS: 00000202
RAX: 0000000003694b25 RBX: ffffc90004397ef0 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8daae6e9 RDI: ffffffff8be250e0
RBP: ffffc90004397f38 R08: ffffffff8fc3de77 R09: 1ffffffff1f87bce
R10: dffffc0000000000 R11: fffffbfff1f87bcf R12: 000000000000000f
R13: 000000000000000f R14: ffffc90004397f48 R15: ffff88807d905ac0
FS: 00007f51c21de6c0(0000) GS:ffff8881259c1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fd24000 CR3: 00000000321d4000 CR4: 00000000003526f0
Call Trace:
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f51c132b829
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007f51c21ddb40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f51c15e5fa8 RCX: 00007f51c132b829
RDX: 00007f51c21ddb40 RSI: 00007f51c21ddc70 RDI: 0000000000000021
RBP: 00007f51c15e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f51c15e6038 R14: 00007ffc9f393b50 R15: 00007ffc9f393c38