rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13489/2:b..l P67/1:b..l P6531/1:b..l P1512/1:b..l P12271/1:b..l P9959/5:b..l rcu: (detected by 0, t=10502 jiffies, g=48513, q=162 ncpus=2) task:syz-executor state:R running task stack:21504 pid:9959 tgid:9959 ppid:9953 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872 Code: e9 30 ff ff ff e8 95 89 83 09 f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 01 67 ae 10 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d ee 54 cd RSP: 0018:ffffc900052d72c8 EFLAGS: 00000282 RAX: c711d4c9923bd700 RBX: 0000000000000246 RCX: 0000000000000046 RDX: 0000000001628b72 RSI: ffffffff8d7c0dbe RDI: ffffffff8ba67680 RBP: 0000000000000000 R08: ffffffff82320c58 R09: ffffffff8ddcb9c0 R10: dffffc0000000000 R11: fffff94000440e39 R12: 0000000000000002 R13: ffffffff8ddcb9c0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] page_table_check_set+0x165/0x610 mm/page_table_check.c:112 page_table_check_ptes_set include/linux/page_table_check.h:83 [inline] set_ptes include/linux/pgtable.h:413 [inline] __copy_present_ptes mm/memory.c:1115 [inline] copy_present_ptes mm/memory.c:1194 [inline] copy_pte_range mm/memory.c:1317 [inline] copy_pmd_range+0x3ad6/0x7c00 mm/memory.c:1405 copy_pud_range mm/memory.c:1442 [inline] copy_p4d_range mm/memory.c:1466 [inline] copy_page_range+0xaf4/0x1120 mm/memory.c:1552 dup_mmap+0xf4c/0x1d50 mm/mmap.c:1841 dup_mm kernel/fork.c:1531 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1583 copy_process+0x18be/0x3cd0 kernel/fork.c:2223 kernel_clone+0x249/0x840 kernel/fork.c:2653 __do_sys_clone kernel/fork.c:2794 [inline] __se_sys_clone kernel/fork.c:2778 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2ae74d5292 RSP: 002b:00007ffe36b6d390 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe36b6d390 RCX: 00007f2ae74d5292 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe36b6d51c R08: 0000000000000000 R09: 0000000000000001 R10: 00005555779ae7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000113f0d R15: 00007ffe36b6d570 task:kworker/u8:32 state:R running task stack:24224 pid:12271 tgid:12271 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: bat_events batadv_tt_purge Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7095 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:194 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline] rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1454 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] batadv_tt_local_purge+0x2ed/0x380 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x35/0xa10 net/batman-adv/translation-table.c:3509 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/u8:12 state:R running task stack:21184 pid:1512 tgid:1512 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7095 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 rt_mutex_wake_up_q kernel/locking/rtmutex.c:575 [inline] rt_mutex_slowunlock+0x681/0x8b0 kernel/locking/rtmutex.c:1469 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] cfg80211_inform_single_bss_data+0x141d/0x1bd0 net/wireless/scan.c:2388 cfg80211_inform_bss_data+0x266/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x760 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline] ieee80211_ibss_rx_queued_mgmt+0x1901/0x2cd0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1748 [inline] ieee80211_iface_work+0x84e/0x1340 net/mac80211/iface.c:1802 cfg80211_wiphy_work+0x2ab/0x4a0 net/wireless/core.c:440 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/u8:18 state:R running task stack:20400 pid:6531 tgid:6531 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7095 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 rt_mutex_wake_up_q kernel/locking/rtmutex.c:575 [inline] rt_mutex_slowunlock+0x681/0x8b0 kernel/locking/rtmutex.c:1469 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] cfg80211_inform_single_bss_data+0x141d/0x1bd0 net/wireless/scan.c:2388 cfg80211_inform_bss_data+0x266/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x760 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline] ieee80211_ibss_rx_queued_mgmt+0x1901/0x2cd0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1748 [inline] ieee80211_iface_work+0x84e/0x1340 net/mac80211/iface.c:1802 cfg80211_wiphy_work+0x2ab/0x4a0 net/wireless/core.c:440 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/u8:4 state:R running task stack:21856 pid:67 tgid:67 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7095 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 rt_mutex_wake_up_q kernel/locking/rtmutex.c:575 [inline] rt_mutex_slowunlock+0x681/0x8b0 kernel/locking/rtmutex.c:1469 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] cfg80211_inform_single_bss_data+0x141d/0x1bd0 net/wireless/scan.c:2388 cfg80211_inform_bss_data+0x266/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x760 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline] ieee80211_ibss_rx_queued_mgmt+0x1901/0x2cd0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1748 [inline] ieee80211_iface_work+0x84e/0x1340 net/mac80211/iface.c:1802 cfg80211_wiphy_work+0x2ab/0x4a0 net/wireless/core.c:440 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz.3.1776 state:R running task stack:26880 pid:13489 tgid:13485 ppid:5802 task_flags:0x40054c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__pte_needs_invert arch/x86/include/asm/pgtable-invert.h:18 [inline] RIP: 0010:protnone_mask arch/x86/include/asm/pgtable-invert.h:24 [inline] RIP: 0010:pte_pfn arch/x86/include/asm/pgtable.h:267 [inline] RIP: 0010:vm_normal_page+0x33/0x1a0 mm/memory.c:767 Code: 41 55 41 54 53 49 89 d6 49 89 f7 49 89 fc e8 04 2c b4 ff 31 ff 4c 89 f6 e8 5a 31 b4 ff 4d 85 f6 0f 95 c3 4c 89 f6 48 83 e6 01 <40> 0f 94 c5 31 ff e8 42 31 b4 ff 40 20 dd 40 0f b6 c5 48 f7 d8 4c RSP: 0018:ffffc90004047368 EFLAGS: 00000202 RAX: ffffffff82105476 RBX: 800000004d286001 RCX: ffff88806e4c0000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004047670 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff9400026942f R12: ffff88802a3a1780 R13: dffffc0000000000 R14: 800000004d286007 R15: 00007f51067d3000 zap_present_ptes mm/memory.c:1695 [inline] do_zap_pte_range mm/memory.c:1827 [inline] zap_pte_range mm/memory.c:1929 [inline] zap_pmd_range mm/memory.c:2021 [inline] zap_pud_range mm/memory.c:2049 [inline] zap_p4d_range mm/memory.c:2070 [inline] unmap_page_range+0xb4a/0x4540 mm/memory.c:2091 unmap_single_vma mm/memory.c:2133 [inline] unmap_vmas+0x48f/0x6a0 mm/memory.c:2171 exit_mmap+0x280/0xa10 mm/mmap.c:1302 __mmput+0xcb/0x3d0 kernel/fork.c:1175 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x6a2/0x23c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x125c/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5106eec4ab RSP: 002b:00007f5105143f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 0000000000000005 RCX: 00007f5106eec4ab RDX: 00007f5105144fd0 RSI: 0000000080085502 RDI: 0000000000000005 RBP: 00007f5105144fd0 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000003 R15: 00007f5106fa0ede rcu: rcu_preempt kthread starved for 8642 jiffies! g48513 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:27776 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 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+0x51e/0xb90 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 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: ae 5c 02 e9 13 c4 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 ac 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: 0000:ffffffff8da07dc0 EFLAGS: 00000246 RAX: 0000000002148b5f RBX: ffffffff8199709a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d5648b1 RDI: ffffffff8ba67680 RBP: ffffffff8da07eb0 R08: ffff8880b8833e1b R09: 1ffff110171067c3 R10: dffffc0000000000 R11: ffffed10171067c4 R12: 0000000000000000 R13: 1ffffffff1b605d8 R14: 0000000000000000 R15: 1ffffffff1b605d8 FS: 0000000000000000(0000) GS:ffff888126336000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3250a8 CR3: 00000000612a2000 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:760 start_kernel+0x385/0x3d0 init/main.c:1210 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