rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P156/1:b..l rcu: (detected by 1, t=10502 jiffies, g=23441, q=449 ncpus=2) task:kworker/u8:6 state:R running task stack:21672 pid:156 tgid:156 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7294 irqentry_exit+0x5e4/0x700 kernel/entry/common.c:240 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:101 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x4ea/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: 4c 8b 6c 24 20 0f 84 86 16 00 00 e9 03 02 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 <48> 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 RSP: 0018:ffffc90002e46938 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff90b58600 RCX: 0000000000000000 RDX: ffffffff90b58600 RSI: ffffffff9167654e RDI: ffffffff8c287d80 RBP: ffffffff90b58600 R08: 0000000000000001 R09: ffffffff8e95d260 R10: ffffc90002e46a58 R11: ffffffff81b15a30 R12: ffffffff8b3fc323 R13: ffffffff90b58600 R14: ffffc90002e46a08 R15: 00000000000a3fc3 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905 lsm_inode_alloc security/security.c:229 [inline] security_inode_alloc+0x39/0x310 security/security.c:1190 inode_init_always_gfp+0x9c8/0xda0 fs/inode.c:305 inode_init_always include/linux/fs.h:2930 [inline] alloc_inode+0x82/0x1b0 fs/inode.c:352 new_inode+0x22/0x170 fs/inode.c:1179 debugfs_get_inode fs/debugfs/inode.c:72 [inline] __debugfs_create_file+0xb8/0x400 fs/debugfs/inode.c:433 debugfs_create_file_short+0x3f/0x60 fs/debugfs/inode.c:471 add_common_files net/mac80211/debugfs_netdev.c:824 [inline] add_files net/mac80211/debugfs_netdev.c:946 [inline] ieee80211_debugfs_add_netdev net/mac80211/debugfs_netdev.c:1010 [inline] ieee80211_debugfs_recreate_netdev+0x374/0x1460 net/mac80211/debugfs_netdev.c:1034 drv_remove_interface+0x1ed/0x570 net/mac80211/driver-ops.c:125 ieee80211_do_stop+0x15de/0x2010 net/mac80211/iface.c:726 ieee80211_stop+0x1b1/0x220 net/mac80211/iface.c:832 __dev_close_many+0x36d/0x6e0 net/core/dev.c:1774 netif_close_many+0x225/0x420 net/core/dev.c:1799 netif_close+0x160/0x220 net/core/dev.c:1816 dev_close+0x10a/0x220 net/core/dev_api.c:220 cfg80211_shutdown_all_interfaces+0xb0/0x200 net/wireless/core.c:339 ieee80211_remove_interfaces+0x108/0x6c0 net/mac80211/iface.c:2424 ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1712 mac80211_hwsim_del_radio+0x28a/0x490 drivers/net/wireless/virtual/mac80211_hwsim.c:6132 hwsim_exit_net+0xede/0xfa0 drivers/net/wireless/virtual/mac80211_hwsim.c:7029 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10346 jiffies! g23441 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:27528 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 __schedule_loop kernel/sched/core.c:7049 [inline] schedule+0x164/0x360 kernel/sched/core.c:7064 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: ac 78 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 21 1a 00 fb f4 3c f0 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0000:ffffc90000197e20 EFLAGS: 00000246 RAX: 00000000001da4d1 RBX: ffffffff819b142a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dfc0ce0 RDI: ffffffff8c287de0 RBP: ffffc90000197f10 R08: ffff8880b87339db R09: 1ffff110170e673b R10: dffffc0000000000 R11: ffffed10170e673c R12: 0000000000000001 R13: 1ffff11003bd0000 R14: 0000000000000001 R15: 1ffff11003bd0000 FS: 0000000000000000(0000) GS:ffff88812535c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7f2ec34000 CR3: 000000005f480000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147