rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5807/1:b..l P5924/1:b..l P7983/1:b..l rcu: (detected by 1, t=10502 jiffies, g=28825, q=426 ncpus=2) task:syz-executor state:R running task stack:23800 pid:7983 tgid:7983 ppid:7973 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7095 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+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:389 [inline] copy_pte_range mm/memory.c:1344 [inline] copy_pmd_range mm/memory.c:1405 [inline] copy_pud_range mm/memory.c:1442 [inline] copy_p4d_range mm/memory.c:1466 [inline] copy_page_range+0x1ecd/0x6600 mm/memory.c:1552 dup_mmap+0xd25/0x2180 mm/mmap.c:1841 dup_mm kernel/fork.c:1531 [inline] copy_mm kernel/fork.c:1583 [inline] copy_process+0x7523/0x7a40 kernel/fork.c:2223 kernel_clone+0xfc/0x9a0 kernel/fork.c:2653 __do_sys_clone+0xd9/0x120 kernel/fork.c:2794 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe769bc5292 RSP: 002b:00007fffa630da40 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fffa630da40 RCX: 00007fe769bc5292 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007fffa630dbcc R08: 0000000000000000 R09: 0000000000000001 R10: 0000555558a977d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000058 R14: 000000000004dff5 R15: 00007fffa630dc20 task:kworker/0:8 state:R running task stack:21880 pid:5924 tgid:5924 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:228 [inline] RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline] RIP: 0010:gc_worker+0x2bb/0x1630 net/netfilter/nf_conntrack_core.c:1548 Code: 00 00 48 c7 c7 68 7a da 90 e8 a1 35 36 f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 8f 19 5a f8 58 48 85 db 0f 85 97 0f 00 00 a0 1e 5a f8 8b 1d 1a a1 2b 07 89 dd 31 ff 83 e5 01 89 ee e8 3c RSP: 0018:ffffc90004c7fb48 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89aee3d6 RDX: ffff888027e10000 RSI: ffffffff89aee3e5 RDI: ffff888027e10000 RBP: 0000000000020903 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000040000 R14: 0000000000010482 R15: 0000000000001a29 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz-executor state:R running task stack:23496 pid:5807 tgid:5807 ppid:5802 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5872 Code: 05 bb 36 29 12 83 f8 07 0f 87 f0 00 00 00 48 0f a3 05 86 bc f4 0e 0f 82 c2 02 00 00 8b 35 6e f0 f4 0e 85 f6 0f 85 dd 00 00 00 <48> 8b 44 24 30 65 48 2b 05 5d 36 29 12 0f 85 02 03 00 00 48 83 c4 RSP: 0018:ffffc900032a6fc8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000003 RDX: 0000000000000000 RSI: ffffffff8de53c03 RDI: ffffffff8c1b1a20 RBP: ffffffff8e7e7920 R08: 000000001cadd436 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 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_zero+0x8c/0x410 mm/page_table_check.c:138 page_table_check_alloc include/linux/page_table_check.h:38 [inline] post_alloc_hook+0x140/0x170 mm/page_alloc.c:1890 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2490 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline] alloc_pages_noprof+0x136/0x390 mm/mempolicy.c:2581 pagetable_alloc_noprof include/linux/mm.h:3404 [inline] __pud_alloc_one_noprof include/asm-generic/pgalloc.h:181 [inline] pud_alloc_one_noprof include/asm-generic/pgalloc.h:206 [inline] __pud_alloc+0x3b/0x690 mm/memory.c:6686 pud_alloc include/linux/mm.h:3314 [inline] copy_pud_range mm/memory.c:1422 [inline] copy_p4d_range mm/memory.c:1466 [inline] copy_page_range+0x3f74/0x6600 mm/memory.c:1552 dup_mmap+0xd25/0x2180 mm/mmap.c:1841 dup_mm kernel/fork.c:1531 [inline] copy_mm kernel/fork.c:1583 [inline] copy_process+0x7523/0x7a40 kernel/fork.c:2223 kernel_clone+0xfc/0x9a0 kernel/fork.c:2653 __do_sys_clone+0xd9/0x120 kernel/fork.c:2794 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa385dc5292 RSP: 002b:00007fff8522b770 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fff8522b770 RCX: 00007fa385dc5292 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007fff8522b8fc R08: 0000000000000000 R09: 0000000000000001 R10: 00005555780bd7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000057 R14: 000000000004e0de R15: 00007fff8522b950 rcu: rcu_preempt kthread starved for 10052 jiffies! g28825 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27976 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 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+0x754/0xd80 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 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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: d8 81 02 c3 cc cc cc cc 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 a3 91 1a 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000246 RAX: 00000000014f3f59 RBX: ffff88801e6924c0 RCX: ffffffff8b90fc75 RDX: 0000000000000000 RSI: ffffffff8de79d93 RDI: ffffffff8c1b1a20 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a679d R10: ffff8880b8533ceb R11: 0000000000000000 R12: 0000000000000001 R13: ffffed1003cd2498 R14: 0000000000000001 R15: ffffffff90d9c610 FS: 0000000000000000(0000) GS:ffff88812443c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdee399b28 CR3: 0000000076c7b000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:73 [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 sched: DL replenish lagged too much