rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10223/1:b..l P36/1:b..l P5855/1:b..l P9360/1:b..l P4979/2:b..l rcu: (detected by 1, t=10502 jiffies, g=49161, q=526 ncpus=2) task:udevd state:R running task stack:24600 pid:4979 tgid:4979 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 3b a2 26 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 46 40 f3 0e 0f 82 a4 02 00 00 8b 35 ce 73 f3 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd a1 26 12 0f 85 ed 02 00 00 48 83 c4 RSP: 0018:ffffc900034cfcf8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8defcec5 RDI: ffffffff8c1c3a00 RBP: ffffffff8e7e5620 R08: 0000000006fa0785 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] kill_pid_info_type+0x48/0x290 kernel/signal.c:1454 kill_pid_info kernel/signal.c:1471 [inline] kill_proc_info+0x6f/0x1b0 kernel/signal.c:1478 kill_something_info+0x2a0/0x310 kernel/signal.c:1575 __do_sys_kill kernel/signal.c:3956 [inline] __se_sys_kill kernel/signal.c:3950 [inline] __x64_sys_kill+0x1c4/0x250 kernel/signal.c:3950 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f23e7e5f357 RSP: 002b:00007ffd9bab3f28 EFLAGS: 00000297 ORIG_RAX: 000000000000003e RAX: ffffffffffffffda RBX: 00007ffd9bab3f30 RCX: 00007f23e7e5f357 RDX: 0000560daa1c1470 RSI: 000000000000000f RDI: 00000000000015e0 RBP: 0000000000000000 R08: 0000000000000010 R09: 0000560daa1a6020 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 0000560d972c7100 R14: 0000000000000000 R15: 0000000000000000 task:kworker/u8:14 state:R running task stack:22264 pid:9360 tgid:9360 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x4d6/0x2090 arch/x86/kernel/unwind_orc.c:520 Code: e8 6f f3 ff ff 48 89 c1 48 85 c0 0f 84 dc 06 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 79 05 4c 89 fa 48 c1 ea 03 0f b6 04 02 <4c> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 51 15 00 00 0f b6 41 05 RSP: 0018:ffffc900056b6df8 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff921f57c8 RDX: 1ffffffff243eaf9 RSI: 0000000000000000 RDI: ffffffff9160709c RBP: ffffc900056b6eb0 R08: ffffffff921f57ce R09: 0000000000000007 R10: 0000000000000200 R11: 000000000009dbce R12: ffffc900056b6eb8 R13: ffffc900056b6e68 R14: ffffc900056b6e9d R15: ffffffff921f57cd arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] cfg80211_inform_single_bss_data+0x557/0x1de0 net/wireless/scan.c:2344 cfg80211_inform_bss_data+0x237/0x3a00 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x247/0x780 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1088 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1569 [inline] ieee80211_ibss_rx_queued_mgmt+0x1922/0x2f80 net/mac80211/ibss.c:1596 ieee80211_iface_process_skb net/mac80211/iface.c:1795 [inline] ieee80211_iface_work+0xbff/0x13e0 net/mac80211/iface.c:1849 cfg80211_wiphy_work+0x410/0x570 net/wireless/core.c:513 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/u8:9 state:R running task stack:24056 pid:5855 tgid:5855 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5893 Code: ff 65 0f c1 05 db e2 26 12 83 f8 01 0f 85 28 01 00 00 9c 58 f6 c4 02 0f 85 13 01 00 00 41 f7 c6 00 02 00 00 0f 85 c0 00 00 00 <48> 8b 44 24 10 65 48 2b 05 2d 9b 26 12 0f 85 4e 01 00 00 48 83 c4 RSP: 0018:ffffc900054072a0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e7e5620 RCX: ffffc900054072ac RDX: 0000000000000003 RSI: ffffffff8defcec5 RDI: ffffffff8c1c3a00 RBP: ffffffff81b7d1ae R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 00000000000a006c R12: ffff88803257a500 R13: ffffc90005407358 R14: 0000000000000202 R15: 0000000000000004 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] ieee802_11_parse_elems_full+0x177/0x3720 net/mac80211/parse.c:1051 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2518 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1565 [inline] ieee80211_ibss_rx_queued_mgmt+0xc8d/0x2f80 net/mac80211/ibss.c:1596 ieee80211_iface_process_skb net/mac80211/iface.c:1795 [inline] ieee80211_iface_work+0xbff/0x13e0 net/mac80211/iface.c:1849 cfg80211_wiphy_work+0x410/0x570 net/wireless/core.c:513 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/u8:2 state:R running task stack:22832 pid:36 tgid:36 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5893 Code: ff 65 0f c1 05 db e2 26 12 83 f8 01 0f 85 28 01 00 00 9c 58 f6 c4 02 0f 85 13 01 00 00 41 f7 c6 00 02 00 00 0f 85 c0 00 00 00 <48> 8b 44 24 10 65 48 2b 05 2d 9b 26 12 0f 85 4e 01 00 00 48 83 c4 RSP: 0018:ffffc90000ac6db0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e7e5620 RCX: ffffc90000ac6dbc RDX: 0000000000000003 RSI: ffffffff8defcec5 RDI: ffffffff8c1c3a00 RBP: ffffffff81b7d1ae R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000000ced2 R12: ffff888020edca00 R13: ffffc90000ac6e68 R14: 0000000000000202 R15: 0000000000000004 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] cfg80211_inform_single_bss_data+0x557/0x1de0 net/wireless/scan.c:2344 cfg80211_inform_bss_data+0x237/0x3a00 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x247/0x780 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1088 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1569 [inline] ieee80211_ibss_rx_queued_mgmt+0x1922/0x2f80 net/mac80211/ibss.c:1596 ieee80211_iface_process_skb net/mac80211/iface.c:1795 [inline] ieee80211_iface_work+0xbff/0x13e0 net/mac80211/iface.c:1849 cfg80211_wiphy_work+0x410/0x570 net/wireless/core.c:513 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz.2.1149 state:R running task stack:27592 pid:10223 tgid:10210 ppid:5609 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline] _raw_spin_unlock_irq+0x44/0x50 kernel/locking/spinlock.c:206 spin_unlock_irq include/linux/spinlock.h:402 [inline] lruvec_unlock_irq include/linux/memcontrol.h:1486 [inline] folio_isolate_lru+0x63a/0xe90 mm/vmscan.c:1814 collapse_file+0x148f/0x3c20 mm/khugepaged.c:2048 collapse_scan_file mm/khugepaged.c:2412 [inline] collapse_single_pmd+0xeaa/0x3c50 mm/khugepaged.c:2447 madvise_collapse+0x2d6/0x760 mm/khugepaged.c:2869 madvise_vma_behavior+0x10f4/0x2200 mm/madvise.c:1364 madvise_walk_vmas+0x2fe/0xa90 mm/madvise.c:1713 madvise_do_behavior+0x1ea/0x510 mm/madvise.c:1929 do_madvise+0x195/0x240 mm/madvise.c:2022 __do_sys_madvise mm/madvise.c:2031 [inline] __se_sys_madvise mm/madvise.c:2029 [inline] __x64_sys_madvise+0xa9/0x110 mm/madvise.c:2029 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffadc39ce59 RSP: 002b:00007ffadd296028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007ffadc616090 RCX: 00007ffadc39ce59 RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000200000000000 RBP: 00007ffadc432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffadc616128 R14: 00007ffadc616090 R15: 00007ffdea8bed88 rcu: rcu_preempt kthread starved for 10300 jiffies! g49161 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:28216 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7370 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+0x61/0x80 kernel/locking/spinlock.c:198 __debug_object_init+0x2de/0x3d0 lib/debugobjects.c:772 timer_init_key_on_stack+0x2e/0x120 kernel/time/timer.c:816 schedule_timeout+0x115/0x280 kernel/time/sleep_timeout.c:96 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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 Not tainted syzkaller #0 PREEMPT(full) 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: 96 92 02 e9 c3 42 03 00 0f 1f 00 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 63 a1 20 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000246 RAX: 000000000366a9a5 RBX: ffff88801e2ba500 RCX: ffffffff8b8af095 RDX: 0000000000000000 RSI: ffffffff8df223d3 RDI: ffffffff8c1c3a00 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67b5 R10: ffff8880b8533dab R11: 0000000000000000 R12: 0000000000000001 R13: ffffed1003c574a0 R14: 0000000000000001 R15: ffffffff90d7ce50 FS: 0000000000000000(0000) GS:ffff88812446d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efd22b45690 CR3: 0000000047536000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148