rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ff8c/1/0x4000000000000000 softirq=21795/21797 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=17097, q=809 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8302 Comm: syz.0.730 Not tainted 6.14.0-rc1-syzkaller-00130-ge589adf5b70c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline] RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x69/0x120 kernel/locking/spinlock.c:162 Code: b5 41 48 c7 44 24 08 cf 00 08 8e 48 c7 44 24 10 b0 a9 f8 8b 49 89 e5 49 c1 ed 03 48 b8 f1 f1 f1 f1 00 f3 f3 f3 4b 89 44 3d 00 <4c> 89 e3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 e7 e8 51 4d 2d f6 RSP: 0018:ffffc90000a18b40 EFLAGS: 00000802 RAX: f3f3f300f1f1f1f1 RBX: ffffffff9a6158a0 RCX: 00000000000085e0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9a6158a8 RBP: ffffc90000a18bd0 R08: ffffc90000a18c4f R09: 0000000000000000 R10: ffffc90000a18c40 R11: fffff5200014318a R12: ffffc90000a18b60 R13: 1ffff92000143168 R14: ffffffff9a6158a8 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000011c7c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_activate+0x17f/0x580 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:455 [inline] debug_activate kernel/time/hrtimer.c:496 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1100 __run_hrtimer kernel/time/hrtimer.c:1818 [inline] __hrtimer_run_queues+0x6cb/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+0x110/0x420 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:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5876 Code: 3c 3b 00 74 08 4c 89 f7 e8 45 10 8b 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000b80f100 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92001701e32 RCX: ffffc9000b80f103 RDX: 0000000000000003 RSI: ffffffff8c0ab8e0 RDI: ffffffff8c608a00 RBP: ffffc9000b80f240 R08: ffffffff901b5977 R09: 1ffffffff2036b2e R10: dffffc0000000000 R11: fffffbfff2036b2f R12: 1ffff92001701e2c R13: 0000000000000246 R14: ffffc9000b80f190 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] page_ext_put+0xa3/0xc0 mm/page_ext.c:550 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:1740 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x376d/0x48d0 mm/memory.c:1894 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1984 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 get_signal+0x16b2/0x1750 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f54ad78cde9 Code: Unable to access opcode bytes at 0x7f54ad78cdbf. RSP: 002b:00007ffc05cfa138 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f54ad9a7ba0 RCX: 00007f54ad78cde9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f54ad9a7ba0 R08: 000000000000015c R09: 0000001405cfa42f R10: 00007f54ad9a7ac0 R11: 0000000000000246 R12: 000000000001cd23 R13: 00007f54ad9a6080 R14: ffffffffffffffff R15: 00007ffc05cfa250 rcu: rcu_preempt kthread starved for 10492 jiffies! g17097 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26104 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 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+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/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: CPU: 0 UID: 0 PID: 8349 Comm: syz.2.742 Not tainted 6.14.0-rc1-syzkaller-00130-ge589adf5b70c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1ba4/0x2d30 kernel/smp.c:885 Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 b0 e8 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 60 e4 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00 RSP: 0018:ffffc9000c60f440 EFLAGS: 00000293 RAX: ffffffff81b379e5 RBX: 1ffff110170e88f9 RCX: ffff888025a40000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000c60f640 R08: ffffffff81b379b0 R09: 1ffffffff285f50e R10: dffffc0000000000 R11: fffffbfff285f50f R12: ffff8880b863fb48 R13: ffff8880b87447c8 R14: ffff8880b863fb40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fe20000 CR3: 00000000763be000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline] tlb_flush_mmu+0x1aa/0x680 mm/mmu_gather.c:395 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:488 exit_mmap+0x52a/0xd40 mm/mmap.c:1297 __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 get_signal+0x16b2/0x1750 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244