rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9214/1:b..l rcu: (detected by 1, t=10502 jiffies, g=22621, q=488 ncpus=2) task:syz.3.793 state:R running task stack:24016 pid:9214 tgid:9212 ppid:5837 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] finish_fault+0x10bb/0x1290 mm/memory.c:5280 do_read_fault mm/memory.c:5414 [inline] do_fault mm/memory.c:5544 [inline] do_pte_missing mm/memory.c:4060 [inline] handle_pte_fault mm/memory.c:5907 [inline] __handle_mm_fault+0x4c6f/0x70f0 mm/memory.c:6050 handle_mm_fault+0x3e5/0x8d0 mm/memory.c:6219 faultin_page mm/gup.c:1196 [inline] __get_user_pages+0x1a92/0x4140 mm/gup.c:1491 populate_vma_page_range+0x264/0x330 mm/gup.c:1929 __mm_populate+0x27a/0x460 mm/gup.c:2032 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x303/0x430 mm/util.c:580 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f629038d169 RSP: 002b:00007f629121e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f62905a5fa0 RCX: 00007f629038d169 RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000400000000000 RBP: 00007f629040e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f62905a5fa0 R15: 00007ffd174fe0e8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g22621 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=10877 rcu: rcu_preempt kthread starved for 10502 jiffies! g22621 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26104 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9211 Comm: syz.2.794 Not tainted 6.14.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:advance_sched+0x5f2/0xca0 net/sched/sch_taprio.c:964 Code: 74 24 28 48 8b 5c 24 30 74 08 48 89 df e8 b6 34 24 f8 48 8b 1b 42 80 7c 25 00 00 48 8b 6c 24 40 74 08 4c 89 ef e8 9e 34 24 f8 <4b> 03 1c fe 48 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 RSP: 0018:ffffc90000007c70 EFLAGS: 00000046 RAX: 1ffff110067d9a2a RBX: 1830c49434000000 RCX: ffff888030d73c00 RDX: 0000000000010000 RSI: 0000000004000000 RDI: 0000000000000000 RBP: ffff888033ecd0c0 R08: ffffffff8a04efc3 R09: fffff52000000f7c R10: dffffc0000000000 R11: fffff52000000f7c R12: dffffc0000000000 R13: ffff888033ecd000 R14: ffff888033ecd000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3051bff8 CR3: 0000000031c8a000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x59d/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_preemption_disabled+0x2/0x120 lib/smp_processor_id.c:13 Code: fd 80 8c 48 c7 c6 00 fe 80 8c eb 1c 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 <41> 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 RSP: 0018:ffffc9000323f440 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffffea0001b33c40 RCX: ffff888030d73c00 RDX: ffff888030d73c00 RSI: ffffffff8c80fe00 RDI: ffffffff8c80fdc0 RBP: 0000000000000001 R08: ffffffff8234f1c1 R09: 1ffffffff28a9908 R10: dffffc0000000000 R11: fffffbfff28a9909 R12: 1ffff110067a7c3c R13: dffffc0000000000 R14: ffffffff8234f190 R15: ffffea0001b33c40 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:716 rcu_read_lock include/linux/rcupdate.h:850 [inline] page_ext_get+0x5a/0x2a0 mm/page_ext.c:525 page_table_check_clear+0x4b/0x550 mm/page_table_check.c:74 get_and_clear_full_ptes include/linux/pgtable.h:712 [inline] zap_present_folio_ptes mm/memory.c:1511 [inline] zap_present_ptes mm/memory.c:1596 [inline] do_zap_pte_range mm/memory.c:1698 [inline] zap_pte_range mm/memory.c:1742 [inline] zap_pmd_range mm/memory.c:1834 [inline] zap_pud_range mm/memory.c:1863 [inline] zap_p4d_range mm/memory.c:1884 [inline] unmap_page_range+0x33fa/0x4510 mm/memory.c:1905 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1995 exit_mmap+0x283/0xd40 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1356 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fccef78d169 Code: Unable to access opcode bytes at 0x7fccef78d13f. RSP: 002b:00007fff9134e118 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fccef78d169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff9134e17c R08: 000000049134e20f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000095 R13: 00000000000927c0 R14: 000000000002b01c R15: 00007fff9134e1d0