rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=41d4/0/0x1 softirq=106328/106329 fqs=147 rcu: (detected by 1, t=10502 jiffies, g=119941, q=167 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__lock_release kernel/locking/lockdep.c:5564 [inline] RIP: 0010:lock_release kernel/locking/lockdep.c:5889 [inline] RIP: 0010:lock_release+0x106/0x310 kernel/locking/lockdep.c:5875 Code: 85 c0 0f 84 88 01 00 00 8b 50 24 85 d2 0f 85 de 01 00 00 66 83 78 22 1f 76 0c 66 83 68 22 20 66 83 78 22 1f 77 62 8b 54 24 0c <41> 89 94 24 98 0b 00 00 48 8b 00 49 89 84 24 90 0b 00 00 41 8d 47 RSP: 0018:ffffc90000007d90 EFLAGS: 00000097 RAX: ffffffff8e892020 RBX: ffff8880777322c0 RCX: ffffc90000007d9c RDX: 0000000000000000 RSI: ffff8880777322c0 RDI: ffffffff8e892020 RBP: ffffffff89c7f2c2 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8e891480 R13: 18c81f219e4b8650 R14: 0000000000000006 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888123dd8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3391eff8 CR3: 000000007e48b000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] advance_sched+0x6a2/0xd20 net/sched/sch_taprio.c:988 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/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: d6 8b 02 c3 cc cc cc cc 0f 1f 00 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 83 5f 10 00 fb f4 3c 4a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e807e10 EFLAGS: 00000246 RAX: 000000000638ad27 RBX: ffffffff8e891480 RCX: ffffffff8bbb42d5 RDX: 0000000000000000 RSI: ffffffff8e1a815f RDI: ffffffff8c402680 RBP: fffffbfff1d12290 R08: 0000000000000001 R09: ffffed101708678d R10: ffff8880b8433c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1d00fc6 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x251/0x260 init/main.c:717 start_kernel+0x48e/0x490 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158 rcu: rcu_preempt kthread starved for 10208 jiffies! g119941 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:28984 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: CPU: 1 UID: 0 PID: 21337 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x593/0x1870 kernel/smp.c:912 Code: 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 44 9a 0c 00 f3 90 41 0f b6 45 00 <41> 38 c4 7c 08 84 c0 0f 85 a8 10 00 00 8b 45 08 31 ff 83 e0 01 41 RSP: 0018:ffffc9001c65f248 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fdc7c2 RDX: ffff8880330da540 RSI: ffffffff81fdc79c RDI: ffff8880330da540 RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880 FS: 00007f525c982880(0000) GS:ffff888123ed8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055dad5c6bff0 CR3: 000000007a928000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1077 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451 flush_tlb_batched_pending+0x93/0xe0 mm/rmap.c:817 zap_pte_range mm/memory.c:1924 [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+0xd5b/0x4a30 mm/memory.c:2109 unmap_vmas+0x299/0x5f0 mm/memory.c:2178 unmap_region+0x1bc/0x3b0 mm/vma.c:488 vms_clear_ptes mm/vma.c:1303 [inline] vms_complete_munmap_vmas+0xa4b/0xdd0 mm/vma.c:1345 do_vmi_align_munmap+0x44f/0x5f0 mm/vma.c:1604 do_vmi_munmap+0x1f8/0x3e0 mm/vma.c:1652 __vm_munmap+0x196/0x390 mm/vma.c:3288 __do_sys_munmap mm/mmap.c:1079 [inline] __se_sys_munmap mm/mmap.c:1076 [inline] __x64_sys_munmap+0x59/0x80 mm/mmap.c:1076 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f525c31e097 Code: 73 01 c3 48 8b 0d 61 2d 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 31 2d 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd58b47b88 EFLAGS: 00000206 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 000055dad5a3ff90 RCX: 00007f525c31e097 RDX: 0000000000000000 RSI: 00000000009480e8 RDI: 00007f525b600000 RBP: 000055dad5a3d2c0 R08: 000055dad5c7d660 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000206 R12: 000055dab0b32588 R13: 00007ffd58b47c10 R14: 0000000000000000 R15: 0000000000000000