rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8653/1:b..l P8055/1:b..l rcu: (detected by 0, t=10502 jiffies, g=82905, q=397 ncpus=2) task:syz-executor state:R running task stack:24128 pid:8055 tgid:8055 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 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:1688 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0xbb8/0x3c10 mm/memory.c:1807 unmap_single_vma+0x194/0x2b0 mm/memory.c:1853 unmap_vmas+0x22f/0x490 mm/memory.c:1897 exit_mmap+0x1b8/0xb20 mm/mmap.c:3412 __mmput+0x12a/0x480 kernel/fork.c:1345 mmput+0x62/0x70 kernel/fork.c:1367 exit_mm kernel/exit.c:571 [inline] do_exit+0x9bf/0x2bb0 kernel/exit.c:869 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 get_signal+0x25fd/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f504016dc57 RSP: 002b:00007fff8c405b60 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000000000000128 RCX: 00007f504016dc57 RDX: 0000000040000000 RSI: 00007fff8c405bbc RDI: 00000000ffffffff RBP: 00007fff8c405bbc R08: 0000000000000000 R09: 00007f5040f25080 R10: 0000000000000000 R11: 0000000000000293 R12: 000055556f9a45eb R13: 000055556f9a4590 R14: 00000000000a337b R15: 00007fff8c405c10 task:udevd state:R running task stack:26960 pid:8653 tgid:8653 ppid:4674 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:207 Code: c3 cc cc cc cc 66 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 65 48 8b 15 c4 5f 79 7e <65> 8b 05 c5 5f 79 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0018:ffffc900034ff438 EFLAGS: 00000286 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff813cf0ff RDX: ffff88807b9ebc00 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffffc900034ffb78 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000000 R12: ffffc900034f8000 R13: ffffc90003500000 R14: ffffc900034ffb80 R15: ffffc900034ff900 unwind_next_frame+0x51/0x23a0 arch/x86/kernel/unwind_orc.c:476 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 save_stack+0x162/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x8d/0x400 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_folios+0x9e9/0x1390 mm/page_alloc.c:2660 folios_put_refs+0x560/0x760 mm/swap.c:1039 free_pages_and_swap_cache+0x36d/0x510 mm/swap_state.c:332 __tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu mm/mmu_gather.c:373 [inline] tlb_finish_mmu+0x168/0x7b0 mm/mmu_gather.c:465 exit_mmap+0x3d1/0xb20 mm/mmap.c:3425 __mmput+0x12a/0x480 kernel/fork.c:1345 mmput+0x62/0x70 kernel/fork.c:1367 exit_mm kernel/exit.c:571 [inline] do_exit+0x9bf/0x2bb0 kernel/exit.c:869 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1040 x64_sys_call+0x14a9/0x16a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe0ec6fca90 RSP: 002b:00007ffcbf7917b8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe0ec6fca90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000007 R09: ab092f88939895e0 R10: 00000000ffffffff R11: 0000000000000206 R12: 0000560555ef02f0 R13: 00007ffcbf7917f8 R14: 0000000000000001 R15: 0000560555ebb2c0 rcu: rcu_preempt kthread starved for 10359 jiffies! g82905 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:27584 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111