rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1933/3:b..l P29/3:b..l rcu: (detected by 1, t=10533 jiffies, g=35913, q=4603 ncpus=2) task:ktimers/1 state:D stack:23016 pid:29 tgid:29 ppid:2 task_flags:0x4208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule_rtlock+0x30/0x70 kernel/sched/core.c:7426 rtlock_slowlock_locked+0x35c9/0x3c20 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:2405 cfg80211_inform_bss_data+0x263/0x3cc0 net/wireless/scan.c:3266 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3358 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:5449 [inline] ieee80211_handle_queued_frames+0xe4/0x1d0 net/mac80211/main.c:452 tasklet_action_common+0x31c/0x600 kernel/softirq.c:970 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] run_ktimerd+0x6a/0x100 kernel/softirq.c:1183 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160 kthread+0x38b/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/u8:14 state:R running task stack:14592 pid:1933 tgid:1933 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7270 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7592 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x910 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:deref_stack_reg+0xa/0x220 arch/x86/kernel/unwind_orc.c:418 Code: ba 00 48 8b 4c 24 18 e9 f2 fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 <48> 83 ec 10 48 89 d3 49 89 f0 49 89 ff 48 be 00 00 00 00 00 fc ff RSP: 0018:ffffc900070068c8 EFLAGS: 00000283 RAX: fffffffffffffff0 RBX: ffffffff90d99b06 RCX: 0000000000000000 RDX: ffffc900070069e8 RSI: ffffc90007007ad0 RDI: ffffc900070069a8 RBP: 1ffffffff21b3361 R08: ffffc90007007ad0 R09: 0000000000000000 R10: ffffc900070069f8 R11: fffff52000e00d41 R12: dffffc0000000000 R13: ffffffff90d99b07 R14: ffffc900070069a8 R15: ffffc900070069f0 unwind_next_frame+0x19bd/0x2550 arch/x86/kernel/unwind_orc.c:-1 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 kasan_save_free_info+0x40/0x50 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:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x1c5/0x6d0 mm/slub.c:6792 ieee80211_inform_bss+0xbda/0x10d0 net/mac80211/scan.c:164 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd98/0x1bf0 net/wireless/scan.c:2410 cfg80211_inform_bss_data+0x263/0x3cc0 net/wireless/scan.c:3266 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3358 ieee80211_bss_info_update+0x791/0xa50 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1065 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1546 [inline] ieee80211_ibss_rx_queued_mgmt+0x1ce3/0x2c40 net/mac80211/ibss.c:1573 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:541 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/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 10577 jiffies! g35913 f0x0 RCU_GP_WAIT_FQS(5) ->state=I rcu: Possible timer handling issue on cpu=1 timer-softirq=37928 rcu: rcu_preempt kthread starved for 10618 jiffies! g35913 f0x0 RCU_GP_WAIT_FQS(5) ->state=I ->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:27688 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330 kthread+0x38b/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 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP 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: 8c 62 02 e9 13 d8 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 d3 cb 13 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: 0000000000570435 RBX: ffffffff819a6770 RCX: 8000000000000001 RDX: 0000000000000001 RSI: ffffffff8d8c9ed3 RDI: ffffffff8bcc2180 RBP: ffffc900001d7f10 R08: ffff8880b8733e9b R09: 1ffff110170e67d3 R10: dffffc0000000000 R11: ffffed10170e67d4 R12: 0000000000000000 R13: 1ffff110039db000 R14: 1ffff9200003afd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125cd4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f54ec70e517 CR3: 000000004296c000 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+0x2e0/0x540 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