rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=3454/1/0x4000000000000000 softirq=118104/118105 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18240/1:b..l rcu: (detected by 1, t=10505 jiffies, g=120549, q=395 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18239 Comm: syz.7.3364 Not tainted 6.14.0-rc4-syzkaller-00242-g7a5668899f54 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0xe8/0x3c40 kernel/locking/lockdep.c:5091 Code: 85 15 14 00 00 44 8b 0d 8a 29 cc 0e 45 85 c9 0f 84 b4 0e 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 80 3c 02 00 <0f> 85 96 2c 00 00 49 8b 04 24 48 3d a0 27 83 93 0f 84 89 0e 00 00 RSP: 0018:ffffc90000007be8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 1ffff110170c58d3 RSI: 1ffff92000000f8f RDI: ffff8880b862c698 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90625817 R11: 0000000000000002 R12: ffff8880b862c698 R13: ffff88805ebf2440 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f97f70106c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000060009178 CR3: 000000005c85c000 CR4: 00000000003526f0 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1805 [inline] __hrtimer_run_queues+0x2be/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__vmcs_writel arch/x86/kvm/vmx/vmx_ops.h:225 [inline] RIP: 0010:vmcs_write16 arch/x86/kvm/vmx/vmx_ops.h:234 [inline] RIP: 0010:__vmx_set_segment+0x390/0x9f0 arch/x86/kvm/vmx/vmx.c:3636 Code: 8b 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 3a 05 00 00 48 89 e8 48 c1 e0 04 44 8b b8 e0 df 64 8b 45 0f 79 fe <2e> 0f 86 93 03 00 00 e8 64 6b 69 00 48 8d 7b 0e 48 b8 00 00 00 00 RSP: 0018:ffffc9000d47f7d0 EFLAGS: 00000202 RAX: 0000000000000050 RBX: ffffc9000d47f858 RCX: ffffc9000c271000 RDX: 1ffffffff16c9c06 RSI: ffffffff815075cc RDI: ffffffff8b64e030 RBP: 0000000000000005 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807be50000 R13: 0000000000000005 R14: 0000000000000058 R15: 000000000000080a load_vmcs12_host_state+0xe3e/0x1850 arch/x86/kvm/vmx/nested.c:4776 nested_vmx_enter_non_root_mode+0x371c/0x46a0 arch/x86/kvm/vmx/nested.c:3647 nested_vmx_run+0x4fc/0x1150 arch/x86/kvm/vmx/nested.c:3738 __vmx_handle_exit arch/x86/kvm/vmx/vmx.c:6629 [inline] vmx_handle_exit+0x6a4/0x1a30 arch/x86/kvm/vmx/vmx.c:6646 vcpu_enter_guest arch/x86/kvm/x86.c:11092 [inline] vcpu_run+0x3032/0x4f50 arch/x86/kvm/x86.c:11253 kvm_arch_vcpu_ioctl_run+0x865/0x17f0 arch/x86/kvm/x86.c:11575 kvm_vcpu_ioctl+0x5ea/0x16b0 virt/kvm/kvm_main.c:4378 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f97f618d169 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:00007f97f7010038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f97f63a5fa0 RCX: 00007f97f618d169 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 000000000000000a RBP: 00007f97f620e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f97f63a5fa0 R15: 00007fff5cd50f38 task:syz.8.3363 state:R running task stack:25952 pid:18240 tgid:18237 ppid:12923 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6944 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] finish_fault+0x9e7/0x1010 mm/memory.c:5273 do_read_fault mm/memory.c:5407 [inline] do_fault mm/memory.c:5537 [inline] do_pte_missing+0xef8/0x3e10 mm/memory.c:4058 handle_pte_fault mm/memory.c:5900 [inline] __handle_mm_fault+0x1166/0x2c60 mm/memory.c:6043 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6212 faultin_page mm/gup.c:1196 [inline] __get_user_pages+0x773/0x36f0 mm/gup.c:1491 populate_vma_page_range+0x27f/0x3a0 mm/gup.c:1929 __mm_populate+0x1d6/0x380 mm/gup.c:2032 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x2d3/0x3a0 mm/util.c:580 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae07d8d169 RSP: 002b:00007fae08b46038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fae07fa5fa0 RCX: 00007fae07d8d169 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000400000000000 RBP: 00007fae07e0e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fae07fa5fa0 R15: 00007ffd9d9b4368 rcu: rcu_preempt kthread starved for 10500 jiffies! g120549 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:28064 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 17862 Comm: kworker/u8:26 Not tainted 6.14.0-rc4-syzkaller-00242-g7a5668899f54 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:write_comp_data+0x42/0x90 kernel/kcov.c:246 Code: a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 2c 16 00 00 85 c0 74 4f 8b 82 08 16 00 00 <83> f8 03 75 44 48 8b 82 10 16 00 00 8b 92 0c 16 00 00 48 8b 38 48 RSP: 0018:ffffc900111b7920 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880b8646a00 RCX: ffffffff81add35a RDX: ffff888048468000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170c8d41 R13: 0000000000000001 R14: ffff8880b873fe80 R15: ffff8880b8646a08 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9233ed56c0 CR3: 000000000df80000 CR4: 00000000003526f0 DR0: 0000000440000000 DR1: 0000000000000008 DR2: 000000000000007f DR3: ffff7ffffffffffd DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0x4ea/0x12c0 kernel/smp.c:885 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2118 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2328 text_poke_flush arch/x86/kernel/alternative.c:2519 [inline] text_poke_flush arch/x86/kernel/alternative.c:2516 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2526 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:850 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:842 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244