rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3559/1:b..l P3066/1:b..l P14119/1:b..l rcu: (detected by 0, t=10502 jiffies, g=82645, q=937 ncpus=2) task:syz-executor state:R running task stack:21592 pid:14119 tgid:14119 ppid:14111 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7078 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:392 [inline] copy_pte_range mm/memory.c:1331 [inline] copy_pmd_range+0x74f2/0x7e00 mm/memory.c:1392 copy_pud_range mm/memory.c:1429 [inline] copy_p4d_range mm/memory.c:1453 [inline] copy_page_range+0xb88/0x11d0 mm/memory.c:1535 dup_mmap+0xf4a/0x1b80 mm/mmap.c:1827 dup_mm kernel/fork.c:1529 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1581 copy_process+0x1812/0x3ba0 kernel/fork.c:2218 kernel_clone+0x21e/0x820 kernel/fork.c:2648 __do_sys_clone kernel/fork.c:2789 [inline] __se_sys_clone kernel/fork.c:2773 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f819c585e93 RSP: 002b:00007ffc2f4fc7e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f819c585e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555592ced7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000ebc14 R15: 00007ffc2f4fc980 task:kworker/u8:10 state:R running task stack:20384 pid:3066 tgid:3066 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:762 [inline] RIP: 0010:batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline] RIP: 0010:batadv_iv_ogm_schedule+0x4de/0xf00 net/batman-adv/bat_iv_ogm.c:873 Code: 05 36 f1 65 04 01 48 c7 c7 60 d3 b3 8c be 54 03 00 00 48 c7 c2 a0 d3 b3 8c e8 2e c2 77 f6 4c 89 f8 48 c1 e8 03 42 80 3c 30 00 <74> 08 4c 89 ff e8 f8 0f 01 f7 4d 8b 2f 4d 85 ed 0f 94 c0 49 81 c5 RSP: 0018:ffffc9000bdff940 EFLAGS: 00000246 RAX: 1ffff11004a31317 RBX: 0000000000000001 RCX: ffff88803074dac0 RDX: 0000000000000000 RSI: ffffffff8be08c40 RDI: ffffffff8be08c00 RBP: ffffc9000bdffa90 R08: ffffffff8b267ae0 R09: ffffffff8e13efa0 R10: dffffc0000000000 R11: ffffed10067e1717 R12: ffff888026ac8b80 R13: ffff888026ac8b90 R14: dffffc0000000000 R15: ffff8880251898b8 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 task:kworker/u8:15 state:R running task stack:20296 pid:3559 tgid:3559 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:debug_lockdep_rcu_enabled+0x2a/0x40 kernel/rcu/update.c:321 Code: f3 0f 1e fa 31 c0 83 3d 13 c7 44 04 00 74 1e 83 3d 0a f6 44 04 00 74 15 65 48 8b 0c 25 08 90 a1 92 31 c0 83 b9 04 0b 00 00 00 <0f> 94 c0 e9 ce d8 02 00 cc cc cc cc cc cc cc cc cc cc cc cc cc cc RSP: 0018:ffffc9000c53f050 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888031eedac0 RDX: ffffffff90310634 RSI: ffffffff903105aa RDI: ffffffff8be08c00 RBP: dffffc0000000000 R08: 000000000000001e R09: ffffffff8e13efa0 R10: ffffc9000c53f178 R11: ffffffff81acb2b0 R12: 1ffff920018a7e25 R13: ffffc9000c53f178 R14: ffffc9000c53f128 R15: ffffffff8173fd75 rcu_read_unlock include/linux/rcupdate.h:879 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1a64/0x23d0 arch/x86/kernel/unwind_orc.c:695 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: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:5677 [inline] __kmalloc_noprof+0x41d/0x800 mm/slub.c:5689 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1200 [inline] ieee802_11_parse_elems_full+0x152/0x2ab0 net/mac80211/parse.c:1031 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2469 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1571 [inline] ieee80211_ibss_rx_queued_mgmt+0x48e/0x2af0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1736 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1790 cfg80211_wiphy_work+0x2ab/0x450 net/wireless/core.c:438 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: rcu_preempt kthread starved for 10598 jiffies! g82645 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26176 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 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 43 be 2a 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:ffffffff8de07dc0 EFLAGS: 000002c2 RAX: 0000000001f04865 RBX: ffffffff8197161e RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d9a0b7f RDI: ffffffff8be08c60 RBP: ffffffff8de07eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff8fa25d70 R13: 1ffffffff1bd29b8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c07000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f62caf96f98 CR3: 000000002a212000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000ffe8 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x386/0x3d0 init/main.c:1207 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/0x147