rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1020/2:b..l P29/3:b..l rcu: (detected by 1, t=10502 jiffies, g=16037, q=785 ncpus=2) task:ktimers/1 state:D stack:24424 pid:29 tgid:29 ppid:2 task_flags:0x4208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule_rtlock+0x30/0x70 kernel/sched/core.c:7390 rtlock_slowlock_locked+0x35c5/0x3c20 kernel/locking/rtmutex.c:1895 rtlock_slowlock kernel/locking/rtmutex.c:1922 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] cfg80211_inform_single_bss_data+0xc22/0x1bf0 net/wireless/scan.c:2377 cfg80211_inform_bss_data+0x25b/0x3d50 net/wireless/scan.c:3241 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3333 ieee80211_bss_info_update+0x791/0xa50 net/mac80211/scan.c:230 ieee80211_scan_rx+0x552/0xa40 net/mac80211/scan.c:364 __ieee80211_rx_handle_packet net/mac80211/rx.c:5427 [inline] ieee80211_rx_list+0x2d23/0x3b40 net/mac80211/rx.c:5720 ieee80211_rx_napi+0x1ad/0x3d0 net/mac80211/rx.c:5743 ieee80211_rx include/net/mac80211.h:5437 [inline] ieee80211_handle_queued_frames+0xe4/0x1d0 net/mac80211/main.c:452 tasklet_action_common+0x31c/0x600 kernel/softirq.c:938 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1151 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160 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 task:kworker/u8:9 state:R running task stack:24336 pid:1020 tgid:1020 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 61 2a a2 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 cb 44 fc 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 18 4d 11 RSP: 0018:ffffc90005a36a60 EFLAGS: 00000286 RAX: 84367c090b401200 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000f38ea104 RSI: ffffffff8daf08ba RDI: ffffffff8bca5980 RBP: ffffffff82244e08 R08: ffffffff82244e08 R09: 0000000000000000 R10: 0000000000008000 R11: ffff8880b8640728 R12: 0000000000000000 R13: ffff8880b8640728 R14: 0000000000000001 R15: 0000000000000246 __rt_spin_trylock kernel/locking/spinlock_rt.c:126 [inline] rt_spin_trylock+0xfc/0x2b0 kernel/locking/spinlock_rt.c:135 __pcs_replace_empty_main+0x4a8/0x690 mm/slub.c:4689 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x544/0x780 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] ieee802_11_parse_elems_full+0x14b/0x2db0 net/mac80211/parse.c:1073 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2551 [inline] ieee80211_inform_bss+0x163/0x10d0 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd98/0x1bf0 net/wireless/scan.c:2382 cfg80211_inform_bss_data+0x25b/0x3d50 net/wireless/scan.c:3241 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3333 ieee80211_bss_info_update+0x791/0xa50 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1063 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1544 [inline] ieee80211_ibss_rx_queued_mgmt+0x1ce3/0x2c40 net/mac80211/ibss.c:1571 ieee80211_iface_process_skb net/mac80211/iface.c:1769 [inline] ieee80211_iface_work+0x78a/0x1010 net/mac80211/iface.c:1823 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:538 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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 timer wakeup didn't happen for 10501 jiffies! g16037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=11501 rcu: rcu_preempt kthread starved for 10502 jiffies! g16037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:23840 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 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_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 0b 70 02 e9 13 d0 03 00 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 f3 f8 25 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc900001d7e40 EFLAGS: 00000246 RAX: 0000000000067a27 RBX: ffffffff819a147c RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d88120a RDI: ffffffff8bca5980 RBP: ffffc900001d7f10 R08: ffff8880b8733d5b R09: 1ffff110170e67ab R10: dffffc0000000000 R11: ffffed10170e67ac R12: 0000000000000000 R13: 1ffff110039d1000 R14: 1ffff9200003afd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d46000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555618717a8 CR3: 000000000dfb0000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x1cc/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x157