rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5352/1:b..l P4541/1:b..l rcu: (detected by 1, t=10502 jiffies, g=9425, q=1296 ncpus=2) task:udevd state:R running task stack:25040 pid:4541 tgid:4541 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6924 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6948 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] zap_pte_range mm/memory.c:1682 [inline] zap_pmd_range mm/memory.c:1730 [inline] zap_pud_range mm/memory.c:1759 [inline] zap_p4d_range mm/memory.c:1780 [inline] unmap_page_range+0x40f7/0x4bf0 mm/memory.c:1801 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1891 exit_mmap+0x264/0xc80 mm/mmap.c:3341 __mmput+0x115/0x3c0 kernel/fork.c:1346 exit_mm+0x220/0x310 kernel/exit.c:565 do_exit+0x9aa/0x27e0 kernel/exit.c:861 do_group_exit+0x207/0x2c0 kernel/exit.c:1023 get_signal+0x16a1/0x1740 kernel/signal.c:2909 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1dc06fca12 RSP: 002b:00007ffccdac19a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 0000555765020901 RCX: 00007f1dc06fca12 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000004 R08: 0000000000000000 R09: 0000555764fd4910 R10: 00007f1dc0b8ff50 R11: 0000000000000246 R12: 00005557650213b0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000555764fd4910 task:syz-executor.0 state:R running task stack:25632 pid:5352 tgid:5350 ppid:5120 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rol32 include/linux/bitops.h:122 [inline] RIP: 0010:jhash2 include/linux/jhash.h:129 [inline] RIP: 0010:hash_stack lib/stackdepot.c:514 [inline] RIP: 0010:stack_depot_save_flags+0x84/0x830 lib/stackdepot.c:614 Code: 04 72 75 44 89 f3 44 89 f0 4c 8b 44 24 08 4c 89 c2 03 02 03 5a 04 44 03 72 08 44 89 f7 c1 c7 04 44 29 f0 31 c7 41 01 de 29 fb <89> fd c1 c5 06 31 dd 44 01 f7 89 e9 c1 c1 08 41 29 ee 44 31 f1 01 RSP: 0018:ffffc90004627440 EFLAGS: 00000283 RAX: 00000000ff4e88e8 RBX: 00000000a836a8b9 RCX: 00000000a0acd20b RDX: ffffc900046274f8 RSI: 000000000000000a RDI: 00000000f5c99a06 RBP: 00000000b818f3b2 R08: ffffc900046274e0 R09: 0000000000000008 R10: dffffc0000000000 R11: fffffbfff1f5a9be R12: dffffc0000000000 R13: 1ffff920008c4e98 R14: 000000007ea8b3ed R15: 1ffff110045e4bf0 save_stack+0x109/0x1f0 mm/page_owner.c:157 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_folios+0xf23/0x19e0 mm/page_alloc.c:2632 folios_put_refs+0x93a/0xa60 mm/swap.c:1024 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x6de/0x1df0 mm/shmem.c:1005 shmem_fallocate+0x1071/0x11f0 mm/shmem.c:3183 vfs_fallocate+0x566/0x6c0 fs/open.c:330 ksys_fallocate fs/open.c:353 [inline] __do_sys_fallocate fs/open.c:361 [inline] __se_sys_fallocate fs/open.c:359 [inline] __x64_sys_fallocate+0xbd/0x110 fs/open.c:359 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: 0033:0x7f4f47c7cea9 RSP: 002b:00007f4f489d30c8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f4f47db3f80 RCX: 00007f4f47c7cea9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f4f47cebff4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008000007 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f4f47db3f80 R15: 00007ffd53741198 rcu: rcu_preempt kthread starved for 10583 jiffies! g9425 f0x0 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:24176 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.10.0-rc3-syzkaller-00022-gcea2a26553ac #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:113 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 00 d5 03 00 48 f7 00 08 00 00 00 75 10 eb 07 0f 00 2d e5 c5 a2 00 f3 0f 1e fa fb f4 e9 84 82 29 00 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d08 EFLAGS: 00000246 RAX: ffff888017ae0000 RBX: ffff88801b6a2064 RCX: 00000000000566f9 RDX: 0000000000000001 RSI: ffff88801b6a2000 RDI: ffff88801b6a2064 RBP: 000000000003a5b8 R08: ffff8880b9537d0b R09: 1ffff110172a6fa1 R10: dffffc0000000000 R11: ffffffff8b86ba30 R12: ffff88801b37c000 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8eace4e0 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000063e80 CR3: 000000002cfcc000 CR4: 0000000000350ef0 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:707 cpuidle_enter_state+0x114/0x480 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:332 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:430 start_secondary+0x100/0x100 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x147