rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l P2113/1:b..l P3688/2:b..l P9155/2:b..l P56/1:b..l P102/1:b..l rcu: (detected by 0, t=10502 jiffies, g=31077, q=150 ncpus=2) task:kworker/u8:5 state:R running task stack:21536 pid:102 tgid:102 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7521 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x780 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5874 Code: ff ff ff e8 31 19 88 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0b a4 cf 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 58 87 ed RSP: 0018:ffffc90001586e30 EFLAGS: 00000286 RAX: 0d7d133b47a5be00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000ae02ccdb RSI: ffffffff8d885404 RDI: ffffffff8ba85b60 RBP: ffffffff8b2af03c R08: ffffffff8b2af03c R09: ffffffff8dfc8300 R10: dffffc0000000000 R11: fffffbfff1f157ff R12: 0000000000000002 R13: ffffffff8dfc8300 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] __rt_spin_trylock kernel/locking/spinlock_rt.c:110 [inline] rt_spin_trylock+0x128/0x2b0 kernel/locking/spinlock_rt.c:118 alloc_from_pcs mm/slub.c:4756 [inline] slab_alloc_node mm/slub.c:4896 [inline] __do_kmalloc_node mm/slub.c:5307 [inline] __kmalloc_noprof+0x1fd/0x7b0 mm/slub.c:5320 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] cfg80211_inform_single_bss_data+0x932/0x1b80 net/wireless/scan.c:2344 cfg80211_inform_bss_data+0x25d/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x730 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1091 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1572 [inline] ieee80211_ibss_rx_queued_mgmt+0x1901/0x2cb0 net/mac80211/ibss.c:1599 ieee80211_iface_process_skb net/mac80211/iface.c:1757 [inline] ieee80211_iface_work+0x78b/0x1020 net/mac80211/iface.c:1811 cfg80211_wiphy_work+0x2cf/0x460 net/wireless/core.c:538 process_one_work+0xa31/0x1980 kernel/workqueue.c:3320 process_scheduled_works kernel/workqueue.c:3423 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3509 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/u8:3 state:R running task stack:21120 pid:56 tgid:56 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7378 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 rt_mutex_wake_up_q kernel/locking/rtmutex.c:583 [inline] rt_mutex_slowunlock+0x681/0x8b0 kernel/locking/rtmutex.c:1482 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] cfg80211_inform_single_bss_data+0x1438/0x1b80 net/wireless/scan.c:2388 cfg80211_inform_bss_data+0x25d/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x730 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1091 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1572 [inline] ieee80211_ibss_rx_queued_mgmt+0x1901/0x2cb0 net/mac80211/ibss.c:1599 ieee80211_iface_process_skb net/mac80211/iface.c:1757 [inline] ieee80211_iface_work+0x78b/0x1020 net/mac80211/iface.c:1811 cfg80211_wiphy_work+0x2cf/0x460 net/wireless/core.c:538 process_one_work+0xa31/0x1980 kernel/workqueue.c:3320 process_scheduled_works kernel/workqueue.c:3423 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3509 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:syz.0.701 state:R running task stack:25320 pid:9155 tgid:9152 ppid:5617 task_flags:0x40054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7521 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x780 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x2a/0xa0 kernel/kcov.c:314 Code: f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 48 4b ab 10 65 44 8b 05 68 4b ab 10 41 81 e0 00 00 ff 00 ba 00 01 00 00 23 91 e4 0b 00 00 <41> 89 d1 45 09 c1 74 12 45 85 c0 75 5f 85 d2 74 5b 83 b9 b4 16 00 RSP: 0018:ffffc9000479eff8 EFLAGS: 00000246 RAX: ffffffff8206b0a5 RBX: 0000000000000000 RCX: ffff88801e32dc40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000005 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff94000211381 R12: 0000000000000002 R13: ffff88801cea5548 R14: ffff88801cea5900 R15: 0000000000000001 lru_gen_update_size+0x225/0xd20 include/linux/mm_inline.h:189 lru_gen_del_folio+0x31c/0x540 include/linux/mm_inline.h:301 lruvec_del_folio include/linux/mm_inline.h:385 [inline] __page_cache_release+0x59f/0xd30 mm/swap.c:78 folios_put_refs+0x3ab/0x8f0 mm/swap.c:1032 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x289/0xae0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:841 __dentry_kill+0x1a2/0x690 fs/dcache.c:718 finish_dput+0xc9/0x480 fs/dcache.c:927 __fput+0x6a3/0xa70 fs/file_table.c:518 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x4d0 kernel/entry/common.c:98 task:kworker/u8:11 state:R running task stack:20832 pid:3688 tgid:3688 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: bat_events batadv_mcast_mla_update Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7521 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x780 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5874 Code: ff ff ff e8 31 19 88 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0b a4 cf 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 58 87 ed RSP: 0018:ffffc9000c6c73f8 EFLAGS: 00000282 RAX: ce60bf08bf7dfd00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000007cd821ac RSI: ffffffff8d885404 RDI: ffffffff8ba85b60 RBP: ffffffff8176f286 R08: ffffffff8176f286 R09: ffffffff8dfc8300 R10: ffffc9000c6c7558 R11: ffffffff81afd3e0 R12: 0000000000000002 R13: ffffffff8dfc8300 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 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 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5432 kmalloc_noprof include/linux/slab.h:950 [inline] batadv_mcast_mla_meshif_get_ipv4 net/batman-adv/multicast.c:402 [inline] batadv_mcast_mla_meshif_get net/batman-adv/multicast.c:529 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:909 [inline] batadv_mcast_mla_update+0xfe3/0x3710 net/batman-adv/multicast.c:946 process_one_work+0xa31/0x1980 kernel/workqueue.c:3320 process_scheduled_works kernel/workqueue.c:3423 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3509 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/u8:8 state:R running task stack:22928 pid:2113 tgid:2113 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7378 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 rt_mutex_wake_up_q kernel/locking/rtmutex.c:583 [inline] rt_mutex_slowunlock+0x681/0x8b0 kernel/locking/rtmutex.c:1482 spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline] __wake_up_common_lock+0x18a/0x1e0 kernel/sched/wait.c:127 __wake_up kernel/sched/wait.c:146 [inline] __wake_up_bit kernel/sched/wait_bit.c:129 [inline] wake_up_bit+0xfb/0x150 kernel/sched/wait_bit.c:160 unlock_buffer fs/buffer.c:79 [inline] end_buffer_write_sync+0x102/0x180 fs/buffer.c:174 end_bio_bh_io_sync+0xbd/0x120 fs/buffer.c:2673 blk_update_request+0x57e/0xe60 block/blk-mq.c:1016 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1178 blk_complete_reqs block/blk-mq.c:1253 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1258 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] spin_unlock_bh include/linux/spinlock_rt.h:116 [inline] wg_index_hashtable_insert+0x12e/0x8c0 drivers/net/wireguard/peerlookup.c:126 wg_noise_handshake_create_initiation+0x64e/0x830 drivers/net/wireguard/noise.c:569 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51 process_one_work+0xa31/0x1980 kernel/workqueue.c:3320 process_scheduled_works kernel/workqueue.c:3423 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3509 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/u8:0 state:R running task stack:21120 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7521 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x780 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:unwind_next_frame+0x1a8c/0x2550 arch/x86/kernel/unwind_orc.c:694 Code: 96 c1 4c 39 e0 0f 97 c2 20 ca 80 fa 01 0f 85 63 01 00 00 49 8d 4c 24 08 4c 39 e9 0f 86 55 01 00 00 48 39 c1 0f 87 4c 01 00 00 <4c> 3b a4 24 90 00 00 00 4c 8b 7c 24 50 0f 87 c9 00 00 00 49 8d 5e RSP: 0018:ffffc900001169d8 EFLAGS: 00000283 RAX: ffffc90000118000 RBX: ffffffff90187201 RCX: ffffc90000116b10 RDX: ffffc90000116b01 RSI: dffffc0000000000 RDI: ffffc90000116b10 RBP: dffffc0000000000 R08: ffffc90000116af8 R09: 0000000000000000 R10: ffffc90000116b58 R11: fffff52000022d6d R12: ffffc90000116b08 R13: ffffc90000110000 R14: ffffc90000116b08 R15: ffffc90000116b18 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 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 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5308 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5320 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] cfg80211_inform_single_bss_data+0x932/0x1b80 net/wireless/scan.c:2344 cfg80211_inform_bss_data+0x25d/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x730 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1091 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1572 [inline] ieee80211_ibss_rx_queued_mgmt+0x1901/0x2cb0 net/mac80211/ibss.c:1599 ieee80211_iface_process_skb net/mac80211/iface.c:1757 [inline] ieee80211_iface_work+0x78b/0x1020 net/mac80211/iface.c:1811 cfg80211_wiphy_work+0x2cf/0x460 net/wireless/core.c:538 process_one_work+0xa31/0x1980 kernel/workqueue.c:3320 process_scheduled_works kernel/workqueue.c:3423 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3509 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 10499 jiffies! g31077 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=23995 rcu: rcu_preempt kthread starved for 10500 jiffies! g31077 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27736 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 __schedule_loop kernel/sched/core.c:7276 [inline] schedule+0x164/0x360 kernel/sched/core.c:7291 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11b0 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: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 7b 64 02 e9 83 cc 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 43 eb 20 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:ffffffff8dc07dc0 EFLAGS: 00000246 RAX: 000000000067c9db RBX: ffffffff81997f6a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d624da5 RDI: ffffffff8ba85b60 RBP: ffffffff8dc07eb0 R08: ffff8880b8633d1b R09: 1ffff110170c67a3 R10: dffffc0000000000 R11: ffffed10170c67a4 R12: 0000000000000000 R13: 1ffffffff1b9fdd8 R14: 0000000000000000 R15: 1ffffffff1b9fdd8 FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000004000 CR3: 000000005746a000 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 rest_init+0x2de/0x300 init/main.c:762 start_kernel+0x38a/0x3e0 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x157