rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10503 jiffies, g=31321, q=397 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294973336-4294962833), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10503 jiffies! g31321 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:27360 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9250 Comm: syz.0.667 Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:taprio_set_budgets+0x146/0x3b0 net/sched/sch_taprio.c:671 Code: e6 e8 9e e6 22 f8 49 83 fc 0f 48 89 6c 24 30 0f 87 8a 01 00 00 4d 8d 2c 2f 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 7c 5f 86 f8 4d 89 fe 49 8b 2c 5f 48 RSP: 0018:ffffc90000a08c00 EFLAGS: 00000806 RAX: 1ffff11005253100 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000010 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200014117c R12: 0000000000000000 R13: ffff888029298800 R14: ffff88802929a530 R15: ffff888029298800 FS: 0000000000000000(0000) GS:ffff888125d0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001000 CR3: 000000000df36000 CR4: 00000000003526f0 Call Trace: advance_sched+0x963/0xc90 net/sched/sch_taprio.c:982 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/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+0x108/0x410 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:__sanitizer_cov_trace_const_cmp8+0x7f/0x90 kernel/kcov.c:323 Code: c1 e1 05 4c 8d 51 28 4d 39 ca 77 1e 49 ff c0 4c 89 02 48 c7 44 0a 08 07 00 00 00 48 89 7c 0a 10 48 89 74 0a 18 48 89 44 0a 20 cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffffc9000b1d7548 EFLAGS: 00000293 RAX: ffffffff82111535 RBX: ffffea0001934dc0 RCX: ffff888033270000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffea0001934df3 R09: 1ffffd40003269be R10: dffffc0000000000 R11: fffff940003269bf R12: ffffea0001934dc0 R13: ffff88804b734020 R14: 00000000180400fb R15: dffffc0000000000 munlock_vma_folio mm/internal.h:1054 [inline] __folio_remove_rmap mm/rmap.c:1788 [inline] folio_remove_rmap_ptes+0x6d5/0xaf0 mm/rmap.c:1805 zap_present_folio_ptes mm/memory.c:1651 [inline] zap_present_ptes mm/memory.c:1709 [inline] do_zap_pte_range mm/memory.c:1810 [inline] zap_pte_range mm/memory.c:1854 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x1f7f/0x4370 mm/memory.c:2017 unmap_single_vma mm/memory.c:2060 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2104 exit_mmap+0x248/0xb50 mm/mmap.c:1280 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7fc63138ebe9 Code: Unable to access opcode bytes at 0x7fc63138ebbf. RSP: 002b:00007fff055ca338 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc63138ebe9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff055ca39c R08: 00000008055ca42f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000090 R13: 00000000000927c0 R14: 000000000003efc6 R15: 00007fff055ca3f0