rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=edc4/1/0x4000000000000000 softirq=56284/56288 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9508 rcu: (detected by 0, t=10502 jiffies, g=41817, q=347 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9510 Comm: syz.4.1031 Not tainted 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__netif_schedule+0x269/0x2c0 net/core/dev.c:3381 Code: 2d 19 02 4d 85 f6 74 ea e8 94 e2 79 f8 fb 48 c7 44 24 20 0e 36 e0 45 48 b8 00 00 00 00 00 fc ff df 49 c7 44 05 00 00 00 00 00 <66> 41 c7 44 05 09 00 00 41 c6 44 05 0b 00 65 48 8b 05 11 45 53 09 RSP: 0018:ffffc90000a08b80 EFLAGS: 00000006 RAX: dffffc0000000000 RBX: ffff88807b151000 RCX: ffff888026db3c00 RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: ffffc90000a08c60 R08: ffff88807b15115f R09: 1ffff1100f62a22b R10: dffffc0000000000 R11: ffffed100f62a22c R12: ffff88807b151360 R13: 1ffff92000141174 R14: 1856f2ad78000000 R15: ffff88805b0a1400 FS: 00007f001a3c16c0(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001700000000 CR3: 000000004eb10000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000008 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: advance_sched+0xa9a/0xc90 net/sched/sch_taprio.c:986 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 7b b4 65 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f3 9d 2e f6 65 8b 05 ec 8a 37 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc9000bbe7b60 EFLAGS: 00000206 RAX: 9ae148801738a600 RBX: 0000000000000a06 RCX: 9ae148801738a600 RDX: 0000000000000007 RSI: ffffffff8d96ea1c RDI: 0000000000000001 RBP: ffffc9000bbe7bf0 R08: ffffffff8f9fe1f7 R09: 1ffffffff1f3fc3e R10: dffffc0000000000 R11: fffffbfff1f3fc3f R12: dffffc0000000000 R13: ffff8880b8627ac0 R14: ffff8880b8627ac0 R15: 1ffff9200177cf6c clock_was_set+0x63b/0x7c0 kernel/time/hrtimer.c:972 do_settimeofday64+0x2ec/0x5e0 kernel/time/timekeeping.c:1407 __do_sys_clock_settime kernel/time/posix-timers.c:1132 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1116 [inline] __x64_sys_clock_settime+0x229/0x280 kernel/time/posix-timers.c:1116 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: 0033:0x7f001958e929 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:00007f001a3c1038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f00197b5fa0 RCX: 00007f001958e929 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f0019610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f00197b5fa0 R15: 00007fff48c0d138 task:syz.2.1032 state:R running task stack:24960 pid:9508 tgid:9507 ppid:5831 task_flags:0x400040 flags:0x0000400a Call Trace: sched_show_task+0x49d/0x630 kernel/sched/core.c:7753 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:256 [inline] print_other_cpu_stall+0xfa6/0x1370 kernel/rcu/tree_stall.h:645 check_cpu_stall kernel/rcu/tree_stall.h:821 [inline] rcu_pending kernel/rcu/tree.c:3642 [inline] rcu_sched_clock_irq+0x9d1/0x1090 kernel/rcu/tree.c:2677 update_process_times+0x23c/0x2f0 kernel/time/timer.c:2473 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x39a/0x520 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x4dd/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:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_single+0x3a9/0x590 kernel/smp.c:679 Code: 33 44 89 f6 83 e6 01 31 ff e8 23 95 0b 00 41 83 e6 01 75 11 e8 d8 90 0b 00 4d 89 fe eb 3f e8 ce 90 0b 00 eb 3c 4d 89 fe f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 b1 90 0b 00 RSP: 0018:ffffc9000b97e3c0 EFLAGS: 00000246 RAX: ffffffff81b4bcbf RBX: ffffc9000b97e408 RCX: 0000000000080000 RDX: ffffc9000c7fa000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9000b97e4b0 R08: ffffffff8f9fe1f7 R09: 1ffffffff1f3fc3e R10: dffffc0000000000 R11: ffffffff81702110 R12: 1ffff9200172fc81 R13: dffffc0000000000 R14: 1ffff9200172fc7c R15: 1ffff9200172fc7c loaded_vmcs_clear arch/x86/kvm/vmx/vmx.c:820 [inline] vmx_vcpu_load_vmcs+0x129/0x6b0 arch/x86/kvm/vmx/vmx.c:1460 vmx_vcpu_load+0x93/0x260 arch/x86/kvm/vmx/vmx.c:1518 kvm_arch_vcpu_load+0x285/0xa70 arch/x86/kvm/x86.c:5018 kvm_sched_in+0x7c/0xe0 virt/kvm/kvm_main.c:6341 __fire_sched_in_preempt_notifiers kernel/sched/core.c:4954 [inline] fire_sched_in_preempt_notifiers kernel/sched/core.c:4960 [inline] finish_task_switch+0x85d/0x950 kernel/sched/core.c:5274 context_switch kernel/sched/core.c:5399 [inline] __schedule+0x16aa/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 2b 8e fb 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000b97eb38 EFLAGS: 00000206 RAX: 703f9409e0705500 RBX: 0000000000000000 RCX: 703f9409e0705500 RDX: 0000000000000000 RSI: ffffffff8db5a736 RDI: ffffffff8be1b9c0 RBP: ffffffff81728af5 R08: 0000000000000000 R09: ffffffff81728af5 R10: ffffc9000b97ecf8 R11: ffffffff81ace5b0 R12: 0000000000000002 R13: ffffffff8e13ee60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_frozen_pages_noprof mm/mempolicy.c:2490 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2510 get_free_pages_noprof+0xf/0x80 mm/page_alloc.c:5018 mmu_memory_cache_alloc_obj virt/kvm/kvm_main.c:358 [inline] __kvm_mmu_topup_memory_cache+0x24f/0x610 virt/kvm/kvm_main.c:395 mmu_topup_memory_caches+0xd6/0x170 arch/x86/kvm/mmu/mmu.c:609 kvm_mmu_load+0x9d/0x21f0 arch/x86/kvm/mmu/mmu.c:5895 kvm_mmu_reload arch/x86/kvm/mmu.h:123 [inline] vcpu_enter_guest arch/x86/kvm/x86.c:10971 [inline] vcpu_run+0x4833/0x6f70 arch/x86/kvm/x86.c:11333 kvm_arch_vcpu_ioctl_run+0xfc9/0x1940 arch/x86/kvm/x86.c:11656 kvm_vcpu_ioctl+0x95c/0xe90 virt/kvm/kvm_main.c:4461 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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: 0033:0x7f84e798e929 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:00007f84e88b6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f84e7bb5fa0 RCX: 00007f84e798e929 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f84e7a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f84e7bb5fa0 R15: 00007ffdcd9cf088 rcu: rcu_preempt kthread starved for 10502 jiffies! g41817 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 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+0x70e/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: 9508 Comm: syz.2.1032 Not tainted 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_single+0x3a9/0x590 kernel/smp.c:679 Code: 33 44 89 f6 83 e6 01 31 ff e8 23 95 0b 00 41 83 e6 01 75 11 e8 d8 90 0b 00 4d 89 fe eb 3f e8 ce 90 0b 00 eb 3c 4d 89 fe f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 b1 90 0b 00 RSP: 0018:ffffc9000b97e3c0 EFLAGS: 00000246 RAX: ffffffff81b4bcbf RBX: ffffc9000b97e408 RCX: 0000000000080000 RDX: ffffc9000c7fa000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9000b97e4b0 R08: ffffffff8f9fe1f7 R09: 1ffffffff1f3fc3e R10: dffffc0000000000 R11: ffffffff81702110 R12: 1ffff9200172fc81 R13: dffffc0000000000 R14: 1ffff9200172fc7c R15: 1ffff9200172fc7c FS: 00007f84e88b66c0(0000) GS:ffff888125c85000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000b000 CR3: 000000006c77e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: loaded_vmcs_clear arch/x86/kvm/vmx/vmx.c:820 [inline] vmx_vcpu_load_vmcs+0x129/0x6b0 arch/x86/kvm/vmx/vmx.c:1460 vmx_vcpu_load+0x93/0x260 arch/x86/kvm/vmx/vmx.c:1518 kvm_arch_vcpu_load+0x285/0xa70 arch/x86/kvm/x86.c:5018 kvm_sched_in+0x7c/0xe0 virt/kvm/kvm_main.c:6341 __fire_sched_in_preempt_notifiers kernel/sched/core.c:4954 [inline] fire_sched_in_preempt_notifiers kernel/sched/core.c:4960 [inline] finish_task_switch+0x85d/0x950 kernel/sched/core.c:5274 context_switch kernel/sched/core.c:5399 [inline] __schedule+0x16aa/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 2b 8e fb 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000b97eb38 EFLAGS: 00000206 RAX: 703f9409e0705500 RBX: 0000000000000000 RCX: 703f9409e0705500 RDX: 0000000000000000 RSI: ffffffff8db5a736 RDI: ffffffff8be1b9c0 RBP: ffffffff81728af5 R08: 0000000000000000 R09: ffffffff81728af5 R10: ffffc9000b97ecf8 R11: ffffffff81ace5b0 R12: 0000000000000002 R13: ffffffff8e13ee60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_frozen_pages_noprof mm/mempolicy.c:2490 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2510 get_free_pages_noprof+0xf/0x80 mm/page_alloc.c:5018 mmu_memory_cache_alloc_obj virt/kvm/kvm_main.c:358 [inline] __kvm_mmu_topup_memory_cache+0x24f/0x610 virt/kvm/kvm_main.c:395 mmu_topup_memory_caches+0xd6/0x170 arch/x86/kvm/mmu/mmu.c:609 kvm_mmu_load+0x9d/0x21f0 arch/x86/kvm/mmu/mmu.c:5895 kvm_mmu_reload arch/x86/kvm/mmu.h:123 [inline] vcpu_enter_guest arch/x86/kvm/x86.c:10971 [inline] vcpu_run+0x4833/0x6f70 arch/x86/kvm/x86.c:11333 kvm_arch_vcpu_ioctl_run+0xfc9/0x1940 arch/x86/kvm/x86.c:11656 kvm_vcpu_ioctl+0x95c/0xe90 virt/kvm/kvm_main.c:4461 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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: 0033:0x7f84e798e929 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:00007f84e88b6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f84e7bb5fa0 RCX: 00007f84e798e929 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f84e7a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f84e7bb5fa0 R15: 00007ffdcd9cf088