rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=158077, q=193 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295118156-4295107654), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g158077 f0x2 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:25568 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8188 Comm: syz.5.4801 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x46/0x3e0 kernel/locking/lockdep.c:5879 Code: c0 f6 23 11 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 c3 f6 23 11 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 ac 74 25 0e 73 16 35 e9 08 00 84 c0 75 0d f6 05 3c 5a 0f 0e 01 0f 84 ad 02 00 00 RSP: 0018:ffffc90000a08bf8 EFLAGS: 00000097 RAX: 0000000000000001 RBX: ffff88802ea9e2e8 RCX: 1ffff11005d53c65 RDX: 0000000000010000 RSI: ffffffff899f5f1f RDI: ffff88802ea9e300 RBP: ffff888030dcc550 R08: ffff888030dcc487 R09: 1ffff110061b9890 R10: dffffc0000000000 R11: ffffed10061b9891 R12: ffff88802ea9e340 R13: ffffffff899f5f1f R14: ffff88802ea9e300 R15: ffff888030dcc800 FS: 00007fb7cb9526c0(0000) GS:ffff888125af9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fc15ff8 CR3: 000000009e556000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline] _raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] advance_sched+0x99f/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:1041 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:raw_spin_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1534 Code: cc e8 c1 93 eb 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 53 eb 16 e8 84 29 ee 09 e8 4f 34 35 00 fb 5b <41> 5e 41 5f e9 94 77 ee 09 cc f3 0f 1e fa 49 be 00 00 00 00 00 fc RSP: 0018:ffffc9000da86be8 EFLAGS: 00000282 RAX: 932553b24a7f1200 RBX: ffff8880b8739f80 RCX: 932553b24a7f1200 RDX: 0000000000000006 RSI: ffffffff8dbbd436 RDI: ffffffff8c037200 RBP: ffffc9000da86e10 R08: ffffffff8fc3ee37 R09: 1ffffffff1f87dc6 R10: dffffc0000000000 R11: fffffbfff1f87dc7 R12: dffffc0000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8880b873add8 __schedule+0x19e0/0x4cc0 kernel/sched/core.c:6972 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pud_pgtable arch/x86/include/asm/pgtable.h:1056 [inline] RIP: 0010:pmd_offset include/linux/pgtable.h:146 [inline] RIP: 0010:zap_pmd_range mm/memory.c:1920 [inline] RIP: 0010:zap_pud_range mm/memory.c:1975 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1996 [inline] RIP: 0010:unmap_page_range+0x805/0x4370 mm/memory.c:2017 Code: 85 db 4c 0f 44 f8 48 8b 84 24 60 01 00 00 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 08 e5 dd 8d e8 5b 5e 1a 00 <4d> 21 f7 4c 03 3d 99 77 d3 0b 48 8b 5c 24 70 89 d8 c1 e8 12 25 f8 RSP: 0018:ffffc9000da86f80 EFLAGS: 00000246 RAX: 1ffffffff1bbbca1 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000da87230 R08: ffffc9000da87310 R09: ffffffff820aaa24 R10: 0000000000000000 R11: 0000000300000001 R12: 1ffff11013faa800 R13: 000020000054f000 R14: 000000009fd53067 R15: 000ffffffffff000 unmap_single_vma mm/memory.c:2060 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2104 vms_clear_ptes+0x35c/0x540 mm/vma.c:1228 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1277 do_vmi_align_munmap+0x364/0x440 mm/vma.c:1536 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584 unmap_source_vma mm/mremap.c:1122 [inline] move_vma+0x10eb/0x1820 mm/mremap.c:1315 mremap_to+0x6ce/0x790 mm/mremap.c:1415 do_mremap mm/mremap.c:1940 [inline] __do_sys_mremap mm/mremap.c:1996 [inline] __se_sys_mremap+0xd45/0xfb0 mm/mremap.c:1964 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb7cab8ebe9 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:00007fb7cb952038 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007fb7cadc6270 RCX: 00007fb7cab8ebe9 RDX: 0000000000003000 RSI: 0000000000001000 RDI: 000020000054e000 RBP: 00007fb7cac11e19 R08: 000020000022c000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb7cadc6308 R14: 00007fb7cadc6270 R15: 00007ffc3ecb5238