rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=6d6c/1/0x4000000000000000 softirq=203016/203017 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=204849, q=1962 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31339 Comm: syz.8.6113 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:separate_irq_context kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_acquire+0x726/0x2cf0 kernel/locking/lockdep.c:5221 Code: 08 c1 0f 84 67 20 00 00 49 89 5d 00 45 8b be 28 0b 00 00 4d 85 ff 0f 84 8e 00 00 00 41 83 ff 31 0f 83 ca 23 00 00 4b 8d 04 bf <4d> 89 ec 41 8b 6d 20 48 8b 4c 24 20 8b 44 c1 f8 31 e8 25 00 60 00 RSP: 0018:ffffc90000a08aa8 EFLAGS: 00000087 RAX: 000000000000000a RBX: 37609dba68070e38 RCX: ffffffff9328c3b0 RDX: 0000000000000008 RSI: ffff8880444d2a00 RDI: ffff8880444d1e80 RBP: 0000000000000000 R08: ffffffff8497d557 R09: ffffffff99ac2ff0 R10: dffffc0000000000 R11: fffff52000141198 R12: 0000000000000002 R13: ffff8880444d2a00 R14: ffff8880444d1e80 R15: 0000000000000002 FS: 00007fbd770de6c0(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbec4e0bf98 CR3: 0000000088f33000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 debug_object_activate+0x87/0x540 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:438 [inline] debug_activate kernel/time/hrtimer.c:477 [inline] enqueue_hrtimer+0x30/0x380 kernel/time/hrtimer.c:1081 __run_hrtimer kernel/time/hrtimer.c:1794 [inline] __hrtimer_run_queues+0x636/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_quarantine_put+0x6a/0x1f0 mm/kasan/quarantine.c:237 Code: 98 5d 81 92 01 75 32 41 f7 c7 00 02 00 00 74 05 e8 3b 99 a1 ff 9c 58 a9 00 02 00 00 75 78 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <5b> 41 5c 41 5d 41 5e 41 5f e9 03 1b e9 fe cc 48 8d 80 80 5d 81 92 RSP: 0018:ffffc9000c69f8b8 EFLAGS: 00000206 RAX: 0000000000000001 RBX: ffff88805d9a0d00 RCX: 0000000000000046 RDX: 0000000000000006 RSI: ffffffff8d792135 RDI: ffffffff8bc08360 RBP: 0000000000000000 R08: ffffffff8f822377 R09: 1ffffffff1f0446e R10: dffffc0000000000 R11: fffffbfff1f0446f R12: ffff88813ffa68c0 R13: 0000000000000000 R14: 0000000000095ee0 R15: 0000000000000286 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1c0/0x660 mm/slub.c:6878 bpf_int_jit_compile+0x1156/0x14b0 arch/x86/net/bpf_jit_comp.c:3901 bpf_prog_select_runtime+0x4a3/0x820 kernel/bpf/core.c:2542 bpf_migrate_filter net/core/filter.c:1324 [inline] bpf_prepare_filter+0x1124/0x12c0 net/core/filter.c:1372 sk_attach_filter+0x24/0x140 net/core/filter.c:1556 sk_setsockopt+0x1f83/0x2dc0 net/core/sock.c:1468 do_sock_setsockopt+0x11b/0x1b0 net/socket.c:2318 __sys_setsockopt net/socket.c:2347 [inline] __do_sys_setsockopt net/socket.c:2353 [inline] __se_sys_setsockopt net/socket.c:2350 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2350 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: 0033:0x7fbd7618f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbd770de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fbd763e5fa0 RCX: 00007fbd7618f749 RDX: 000000000000001a RSI: 0000000000000001 RDI: 0000000000000005 RBP: 00007fbd76213f91 R08: 0000000000000010 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbd763e6038 R14: 00007fbd763e5fa0 R15: 00007ffe18eae0b8 rcu: rcu_preempt kthread starved for 10500 jiffies! g204849 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:27480 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 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: 29526 Comm: kworker/u8:46 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xcca/0x1260 kernel/smp.c:877 Code: 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 73 93 0b 00 eb e4 44 RSP: 0018:ffffc9000493f6a0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170e8129 RCX: ffff88802f00db80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000493f7e0 R08: ffffffff8f822377 R09: 1ffffffff1f0446e R10: dffffc0000000000 R11: fffffbfff1f0446f R12: ffff8880b8740948 R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3101aff8 CR3: 000000000dd3a000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:874 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246