rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=eec4/1/0x4000000000000000 softirq=32829/32832 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9018/3:b..l rcu: (detected by 0, t=10506 jiffies, g=28177, q=165 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9004 Comm: syz.0.1027 Not tainted 6.15.0-rc1-syzkaller-00025-gbec7dcbc242c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:lock_release+0xb/0x3e0 kernel/locking/lockdep.c:5874 Code: f9 ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 30 48 89 f5 49 89 ff 48 c7 c3 20 a0 68 93 65 48 RSP: 0018:ffffc90000a08b18 EFLAGS: 00000082 RAX: f3f3f300f1f1f1f1 RBX: ffffffff9a9faaf0 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff850c1d76 RDI: ffffffff9a9fab08 RBP: ffffc90000a08bd0 R08: 0000000000000003 R09: fffff52000141158 R10: dffffc0000000000 R11: fffff52000141158 R12: 1ffff92000141168 R13: dffffc0000000000 R14: ffffc90000a08b60 R15: 0000000000000046 FS: 00007f9df40cb6c0(0000) GS:ffff888125096000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f726783bf98 CR3: 000000004ae0c000 CR4: 0000000000350ef0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x7a/0x140 kernel/locking/spinlock.c:194 debug_object_activate+0x3f6/0x5c0 lib/debugobjects.c:836 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x6d6/0xd40 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 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:lock_release+0x244/0x3e0 arch/x86/include/asm/irqflags.h:-1 Code: 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 0f 85 c3 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 03 <48> 3b 44 24 28 0f 85 82 01 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000300e9a0 EFLAGS: 00000206 RAX: 985f57626af1df00 RBX: ffffffff9368a020 RCX: 0000000000000001 RDX: ffffc9000b871000 RSI: ffffffff8e4fd53d RDI: ffffffff8ca1b6a0 RBP: ffff888027f04718 R08: ffffffff82394c69 R09: 1ffff11003c06323 R10: dffffc0000000000 R11: ffffed1003c06324 R12: 0000000000000001 R13: ffff888027f03c00 R14: 0000000000000206 R15: ffffffff8ed3dfe0 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] __page_table_check_zero+0x3e2/0x510 mm/page_table_check.c:145 page_table_check_alloc include/linux/page_table_check.h:33 [inline] post_alloc_hook+0x207/0x240 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1725 [inline] get_page_from_freelist+0x352b/0x36c0 mm/page_alloc.c:3652 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301 folio_alloc_mpol_noprof+0x36/0x70 mm/mempolicy.c:2320 shmem_alloc_folio mm/shmem.c:1854 [inline] shmem_alloc_and_add_folio+0x490/0x1070 mm/shmem.c:1893 shmem_get_folio_gfp+0x655/0x1800 mm/shmem.c:2533 shmem_fault+0x223/0x5c0 mm/shmem.c:2734 __do_fault+0x137/0x390 mm/memory.c:5098 do_read_fault mm/memory.c:5518 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0x3f0c/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 faultin_page mm/gup.c:1193 [inline] __get_user_pages+0x1adc/0x4180 mm/gup.c:1491 populate_vma_page_range+0x266/0x340 mm/gup.c:1929 __mm_populate+0x27d/0x460 mm/gup.c:2032 mm_populate include/linux/mm.h:3470 [inline] vm_mmap_pgoff+0x390/0x530 mm/util.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9df318d169 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:00007f9df40cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f9df33a5fa0 RCX: 00007f9df318d169 RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f9df320e2a0 R08: ffffffffffffffff R09: 000000006a855000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9df33a5fa0 R15: 00007ffc6b49ca18 task:syz.6.1032 state:R running task stack:26728 pid:9018 tgid:9018 ppid:6630 task_flags:0x400040 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 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] filemap_map_pages+0x13d4/0x1900 mm/filemap.c:3747 do_fault_around mm/memory.c:5476 [inline] do_read_fault mm/memory.c:5509 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0x3d6f/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x45b/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f726686d4cd RSP: 002b:00007fff15d829a0 EFLAGS: 00010212 RAX: 000000110c38c000 RBX: 00007f72676d5720 RCX: 0000000000000004 RDX: 0000000000001de6 RSI: 00000000000001f7 RDI: 0000000000000010 RBP: ffffffff85407de6 R08: 00007f7266ba6038 R09: 00007f7266b92000 R10: 00007f7265fff008 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff85407c66 R15: 0000000000000097 rcu: rcu_preempt kthread starved for 10506 jiffies! g28177 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:26520 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 9014 Comm: syz.3.1030 Not tainted 6.15.0-rc1-syzkaller-00025-gbec7dcbc242c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bb6/0x2d40 kernel/smp.c:885 Code: 89 e6 83 e6 01 31 ff e8 18 e3 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 c8 de 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 01 00 00 00 74 1e e8 a3 de 0b RSP: 0018:ffffc9001ea074a0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff110170e7e91 RCX: 0000000000080000 RDX: ffffc9000c474000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9001ea076a0 R08: ffffffff81b77698 R09: 1ffffffff20bfc0e R10: dffffc0000000000 R11: fffffbfff20bfc0f R12: ffff8880b863ad08 R13: ffff8880b873f488 R14: ffff8880b863ad00 R15: 0000000000000001 FS: 00007fb5414796c0(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb535e3f000 CR3: 000000004ab64000 CR4: 0000000000350ef0 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:1275 [inline] flush_tlb_mm_range+0xb8d/0x13f0 arch/x86/mm/tlb.c:1365 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline] tlb_flush_mmu+0x1aa/0x690 mm/mmu_gather.c:403 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:496 vms_clear_ptes+0x431/0x540 mm/vma.c:1158 vms_complete_munmap_vmas+0x210/0x8f0 mm/vma.c:1200 do_vmi_align_munmap+0x5b9/0x6c0 mm/vma.c:1459 do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1507 __vm_munmap+0x37b/0x520 mm/vma.c:2970 __do_sys_munmap mm/mmap.c:1084 [inline] __se_sys_munmap mm/mmap.c:1081 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb54058d1f7 Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 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:00007fb541478e18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007fb54058d1f7 RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007fb535e00000 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000045a R10: 00000000000003ba R11: 0000000000000246 R12: 0000000000000004 R13: 00007fb541478ef0 R14: 00007fb541478eb0 R15: 00007fb535e00000