rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=1244/1/0x4000000000000000 softirq=19509/19528 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5987/1:b..l rcu: (detected by 1, t=10502 jiffies, g=14441, q=1227 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1097 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:check_preemption_disabled+0x49/0x120 lib/smp_processor_id.c:53 Code: 8b 0d bb fe 25 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 9b fe 25 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> e9 41 ca 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 RSP: 0018:ffffc90000007bd8 EFLAGS: 00000086 RAX: 0000000000000000 RBX: ffffffff899b2f48 RCX: f2e51d9d890ae300 RDX: 0000000000010000 RSI: ffffffff8be33860 RDI: ffffffff8be33820 RBP: 0000000000000001 R08: ffff888023aa715f R09: 1ffff11004754e2b R10: dffffc0000000000 R11: ffffed1004754e2c R12: ffff888023aa7360 R13: ffffffff899b2f48 R14: ffffffff8e139f20 R15: ffff8880278a7400 FS: 0000000000000000(0000) GS:ffff888125c16000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faeba6b4e80 CR3: 000000000df36000 CR4: 00000000003526f0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] advance_sched+0xb23/0xc90 net/sched/sch_taprio.c:992 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0xc9c/0x2390 arch/x86/kernel/unwind_orc.c:-1 Code: 4c 8b 6c 24 50 4c 8b 64 24 10 74 08 48 89 df e8 aa 55 b0 00 4c 89 23 ba 10 00 00 00 4c 89 ef 31 f6 e8 78 57 b0 00 48 8b 14 24 c5 04 00 00 4c 89 7c 24 28 48 89 5c 24 78 4d 8d 66 08 4d 89 e5 RSP: 0018:ffffc90003c1e718 EFLAGS: 00000246 RAX: ffffc90003c1e838 RBX: ffffc90003c1e820 RCX: 0000000000000000 RDX: ffffffff9034bd82 RSI: 0000000000000000 RDI: ffffc90003c1e848 RBP: dffffc0000000000 R08: ffffc90003c1e847 R09: 0000000000000000 R10: ffffc90003c1e838 R11: fffff52000783d09 R12: ffffc90003c1fc80 R13: ffffc90003c1e838 R14: ffffc90003c1e7e8 R15: ffffc90003c1e830 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:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4376 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] ieee802_11_parse_elems_full+0x152/0x2ab0 net/mac80211/parse.c:1011 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2462 [inline] ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2469 [inline] ieee80211_inform_bss+0x10c/0x10a0 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd02/0x1ac0 net/wireless/scan.c:2380 cfg80211_inform_bss_data+0x1fb/0x3b30 net/wireless/scan.c:3235 cfg80211_inform_bss_frame_data+0x3d7/0x730 net/wireless/scan.c:3326 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline] ieee80211_ibss_rx_queued_mgmt+0xa36/0x2ae0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1699 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1753 cfg80211_wiphy_work+0x2b8/0x470 net/wireless/core.c:435 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:udevd state:R running task stack:26232 pid:5987 tgid:5987 ppid:5232 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] wp_page_copy mm/memory.c:3653 [inline] do_wp_page+0x1d1d/0x5800 mm/memory.c:4013 handle_pte_fault mm/memory.c:6068 [inline] __handle_mm_fault+0x1033/0x5440 mm/memory.c:6195 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7faeb9eb5b69 RSP: 002b:00007ffca6fde040 EFLAGS: 00010202 RAX: 00007faeb9ff21d0 RBX: 000055b9c7851540 RCX: 000055b9c7851540 RDX: 000055b9c7851540 RSI: 00007faeb9ff21d0 RDI: 000055b9c7851540 RBP: 00007faeb9ff1ac0 R08: 0000000000002760 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000049c0 R13: 000055b9c7855f00 R14: 0000000000005380 R15: 00007faeb9ff1ac0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g14441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=15338 rcu: rcu_preempt kthread starved for 10502 jiffies! g14441 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:27848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 13 e8 02 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 73 a7 0d 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a07f18 EFLAGS: 00000246 RAX: ffffffff8172213d RBX: 0000000000000003 RCX: ffff888143689e00 RDX: 0000000000000100 RSI: ffffffff8d9b94d9 RDI: ffffffff8be33880 RBP: ffffc90000a07ff0 R08: ffffffff8fa38d37 R09: 1ffffffff1f471a6 R10: dffffc0000000000 R11: fffffbfff1f471a7 R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92000140fe8 FS: 0000000000000000(0000) GS:ffff888125d16000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcbf5200218 CR3: 00000000730aa000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] kvm_wait+0x232/0x290 arch/x86/kernel/kvm.c:1064 pv_wait arch/x86/include/asm/paravirt.h:569 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline] __pv_queued_spin_lock_slowpath+0x7bf/0xb60 kernel/locking/qspinlock.c:325 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116 spin_lock_bh include/linux/spinlock.h:356 [inline] cfg80211_inform_single_bss_data+0xb90/0x1ac0 net/wireless/scan.c:2375 cfg80211_inform_bss_data+0x1fb/0x3b30 net/wireless/scan.c:3235 cfg80211_inform_bss_frame_data+0x3d7/0x730 net/wireless/scan.c:3326 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226 ieee80211_scan_rx+0x593/0xa20 net/mac80211/scan.c:355 __ieee80211_rx_handle_packet net/mac80211/rx.c:5186 [inline] ieee80211_rx_list+0x201c/0x2a90 net/mac80211/rx.c:5423 ieee80211_rx_napi+0x1a8/0x3d0 net/mac80211/rx.c:5446 ieee80211_rx include/net/mac80211.h:5210 [inline] ieee80211_handle_queued_frames+0xe8/0x1f0 net/mac80211/main.c:453 tasklet_action_common+0x36c/0x580 kernel/softirq.c:829 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:stack_trace_consume_entry+0x10f/0x280 kernel/stacktrace.c:93 Code: 8d 3c cb 4c 89 f8 48 c1 e8 03 80 3c 10 00 74 1a 4c 89 ff 48 89 f3 49 89 d4 4c 89 c5 e8 3a e7 76 00 49 89 e8 4c 89 e2 48 89 de <49> 89 37 41 8b 18 41 0f b6 44 15 00 84 c0 0f 85 34 01 00 00 41 3b RSP: 0018:ffffc90000ac7278 EFLAGS: 00000246 RAX: 1ffff92000158e88 RBX: ffffc90000ac7410 RCX: ae827cdc838dae00 RDX: dffffc0000000000 RSI: ffffffff8ac935a8 RDI: ffffc90000ac7380 RBP: 1ffff92000158e72 R08: ffffc90000ac7390 R09: 0000000000000006 R10: ffffc90000ac7318 R11: ffffffff81ac3ae0 R12: 0000000000000000 R13: 1ffff92000158e71 R14: ffffc90000ac7388 R15: ffffc90000ac7440 arch_stack_walk+0x10d/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x18e/0x440 mm/slub.c:4894 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1574 [inline] ieee80211_ibss_rx_queued_mgmt+0x11ef/0x2ae0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1699 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1753 cfg80211_wiphy_work+0x2b8/0x470 net/wireless/core.c:435 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245