rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P26101/1:b..l rcu: (detected by 0, t=10502 jiffies, g=346205, q=443488 ncpus=2) task:syz-executor state:R running task stack:22576 pid:26101 tgid:26101 ppid:1 task_flags:0x40054c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1964 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x4082/0x4f20 mm/memory.c:2109 unmap_vmas+0x390/0x550 mm/memory.c:2178 exit_mmap+0x293/0x9f0 mm/mmap.c:1300 __mmput+0x118/0x420 kernel/fork.c:1187 exit_mm+0x221/0x2d0 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe600d5e90e RSP: 002b:00007fe60114fd48 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000555560abf500 RCX: 00007fe600d5e90e RDX: 0000000040000000 RSI: 00007fe60114fdec RDI: ffffffffffffffff RBP: 00007fe60114fdec R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000001ac R13: 0000555560ad2a00 R14: 00000000001a715a R15: 00007fe60114fe40 rcu: rcu_preempt kthread starved for 449 jiffies! g346205 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:27368 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 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 07/24/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 9c 7e 02 e9 93 06 03 00 cc cc cc 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 d3 2e 18 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000a08cc8 EFLAGS: 00000246 RAX: ffffffff8176c19a RBX: 0000000000000003 RCX: ffff88801e2a0000 RDX: 0000000000000100 RSI: ffffffff8e22f141 RDI: ffffffff8c4bdd80 RBP: 0000000000000003 R08: ffffffff90579e37 R09: 1ffffffff20af3c6 R10: dffffc0000000000 R11: fffffbfff20af3c7 R12: 0000000000000200 R13: 0000000000000000 R14: ffff888044e1d158 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88812504b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000269030 CR3: 00000000263f2000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 0000000000000fea DR2: 0000000000000086 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] kvm_wait+0x10f/0x150 arch/x86/kernel/kvm.c:1096 pv_wait arch/x86/include/asm/paravirt-spinlock.h:83 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline] __pv_queued_spin_lock_slowpath+0x74a/0xbc0 kernel/locking/qspinlock.c:325 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline] queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x26c/0x2f0 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:342 [inline] net_tx_action+0x69e/0xc30 net/core/dev.c:5847 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 9c 7e 02 e9 93 06 03 00 cc cc cc 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 d3 2e 18 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e40 EFLAGS: 00000246 RAX: 00000000029eec95 RBX: ffffffff819b5450 RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8e22f141 RDI: ffffffff8c4bdd80 RBP: ffffc90000197f10 R08: ffff8880b87338db R09: 1ffff110170e671b R10: dffffc0000000000 R11: ffffed10170e671c R12: 0000000000000000 R13: 1ffff11003c54000 R14: 1ffff92000032fd0 R15: dffffc0000000000 arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x2e0/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x157 IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available IPVS: wrr: UDP 224.0.0.2:0 - no destination available