rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=4e7c/1/0x4000000000000000 softirq=77209/77214 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11401/1:b..l rcu: (detected by 0, t=10505 jiffies, g=82285, q=95 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 14754 Comm: syz.1.2285 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:do_raw_spin_lock+0x51/0x290 kernel/locking/spinlock_debug.c:114 Code: 48 89 44 24 60 49 bf 00 00 00 00 00 fc ff df 48 c7 44 24 20 b3 8a b5 41 48 c7 44 24 28 33 d5 ac 8d 48 c7 44 24 30 60 d1 9e 81 <48> 8d 4c 24 20 48 c1 e9 03 48 b8 f1 f1 f1 f1 04 f3 f3 f3 48 89 4c RSP: 0018:ffffc90000a08b20 EFLAGS: 00000082 RAX: f925e355a0203800 RBX: ffffffff99d2aa20 RCX: f925e355a0203800 RDX: 0000000000000000 RSI: ffffffff8db707c4 RDI: ffffffff99d2aa20 RBP: ffffc90000a08bd0 R08: 0000000000000000 R09: ffffffff84c0c66b R10: ffffc90000a08ca0 R11: fffff52000141196 R12: dffffc0000000000 R13: dffffc0000000000 R14: 0000000000000802 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c38fc21 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:zap_present_folio_ptes mm/memory.c:-1 [inline] RIP: 0010:zap_present_ptes mm/memory.c:1590 [inline] RIP: 0010:do_zap_pte_range mm/memory.c:1691 [inline] RIP: 0010:zap_pte_range mm/memory.c:1735 [inline] RIP: 0010:zap_pmd_range mm/memory.c:1827 [inline] RIP: 0010:zap_pud_range mm/memory.c:1856 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1877 [inline] RIP: 0010:unmap_page_range+0x1d6a/0x41c0 mm/memory.c:1898 Code: 1c 37 b8 ff b8 01 00 00 00 ff 8c 84 00 02 00 00 49 bd 00 00 00 00 00 fc ff df 48 8b 7c 24 60 4d 89 fc 4c 89 fe e8 a6 66 6c ff <48> 8b bc 24 98 00 00 00 48 89 fb 48 c1 eb 03 42 80 3c 2b 00 74 0d RSP: 0018:ffffc9000a9c75e0 EFLAGS: 00000293 RAX: ffffffff81745531 RBX: 0000000000000000 RCX: ffff88802d2c3c00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000a9c7890 R08: ffffea0001561c87 R09: 1ffffd40002ac390 R10: dffffc0000000000 R11: fffff940002ac391 R12: 8000000055872007 R13: dffffc0000000000 R14: ffff8880385d1800 R15: 8000000055872007 unmap_single_vma mm/memory.c:1941 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1985 exit_mmap+0x248/0xb50 mm/mmap.c:1284 __mmput+0x118/0x410 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x22e0 kernel/exit.c:952 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 __do_sys_exit_group kernel/exit.c:1116 [inline] __se_sys_exit_group kernel/exit.c:1114 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff95cd8e929 Code: Unable to access opcode bytes at 0x7ff95cd8e8ff. RSP: 002b:00007ffebdedf7c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff95cd8e929 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffebdedf82c R08: 00000009bdedf8bf R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000122 R13: 00000000000927c0 R14: 0000000000123231 R15: 00007ffebdedf880 task:syz-executor state:R running task stack:21600 pid:11401 tgid:11401 ppid:11391 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6790 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6970 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6994 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1206 [inline] copy_pmd_range+0x6727/0x7000 mm/memory.c:1267 copy_pud_range mm/memory.c:1304 [inline] copy_p4d_range mm/memory.c:1328 [inline] copy_page_range+0xc46/0x1270 mm/memory.c:1416 dup_mmap+0xf57/0x1ac0 mm/mmap.c:1838 dup_mm kernel/fork.c:1477 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1529 copy_process+0x16d3/0x3b80 kernel/fork.c:2169 kernel_clone+0x224/0x7f0 kernel/fork.c:2599 __do_sys_clone kernel/fork.c:2742 [inline] __se_sys_clone kernel/fork.c:2726 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbaaa385193 RSP: 002b:00007ffe3693eb18 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbaaa385193 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555694af7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000122f13 R15: 00007ffe3693ecb0 rcu: rcu_preempt kthread starved for 10500 jiffies! g82285 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:26464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0x165/0x360 kernel/sched/core.c:6883 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 1167 Comm: kworker/u8:8 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 c0 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 6b 74 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 50 74 0b RSP: 0018:ffffc90003aaf6a0 EFLAGS: 00000293 RAX: ffffffff81b4b090 RBX: ffff8880b863b040 RCX: ffff88802707da00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003aaf800 R08: ffffffff8fa0bbf7 R09: 1ffffffff1f4177e R10: dffffc0000000000 R11: fffffbfff1f4177f R12: 1ffff110170e7f2d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873f968 FS: 0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000140 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline] smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:855 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245