rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8444/1:b..l P8484/1:b..l rcu: (detected by 0, t=10502 jiffies, g=39805, q=801 ncpus=2) task:syz.3.894 state:R running task stack:25296 pid:8484 tgid:8483 ppid:6308 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 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:rcu_is_watching+0x74/0xb0 kernel/rcu/tree.c:728 Code: 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 22 8b 03 65 ff 0d 71 25 8a 7e 74 10 83 e0 04 c1 e8 02 5b 41 5e 41 5f 22 8f 76 0a e8 92 04 87 ff eb e9 89 d9 80 e1 07 80 c1 03 38 c1 RSP: 0018:ffffc9000316eeb8 EFLAGS: 00000212 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88802a13bc00 RDX: ffff88802a13bc00 RSI: ffffffff8c606460 RDI: ffffffff8c606420 RBP: 0000000000000001 R08: ffffffff81a2285a R09: 1ffffffff26e5d00 R10: dffffc0000000000 R11: fffffbfff26e5d01 R12: ffff88802a13bc00 R13: ffffffff817f1e00 R14: 0000000000000001 R15: 00007f4de41764df rcu_read_lock include/linux/rcupdate.h:839 [inline] is_bpf_text_address+0x63/0x2a0 kernel/bpf/core.c:767 kernel_text_address+0xa7/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __set_page_owner+0x92/0x800 mm/page_owner.c:320 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3442 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4700 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263 folio_alloc_mpol_noprof+0x36/0x50 mm/mempolicy.c:2281 shmem_alloc_folio mm/shmem.c:1722 [inline] shmem_alloc_and_add_folio+0x2cf/0x14f0 mm/shmem.c:1782 shmem_get_folio_gfp+0x8dc/0x2370 mm/shmem.c:2188 shmem_get_folio mm/shmem.c:2293 [inline] shmem_write_begin+0x170/0x4d0 mm/shmem.c:2898 generic_perform_write+0x39b/0x840 mm/filemap.c:4019 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:3074 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa74/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 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: 0033:0x7f4de41764df RSP: 002b:00007f4de4fd6df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f4de41764df RDX: 0000000001000000 RSI: 00007f4dd9800000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005598 R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000004 R13: 00007f4de4fd6ef0 R14: 00007f4de4fd6eb0 R15: 00007f4dd9800000 task:syz.2.886 state:R running task stack:26288 pid:8444 tgid:8443 ppid:6310 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6708 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6732 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+0x3818/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3412 __mmput+0x115/0x390 kernel/fork.c:1345 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x16a1/0x1740 kernel/signal.c:2917 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: 0033:0x7fa9427779f9 RSP: 002b:00007fa9434d20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fa942905f88 RCX: 00007fa9427779f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa942905f88 RBP: 00007fa942905f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa942905f8c R13: 0000000000000000 R14: 00007ffe69ea20d0 R15: 00007ffe69ea21b8 rcu: rcu_preempt kthread starved for 10603 jiffies! g39805 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:26448 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 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: 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+0x21/0x30 drivers/acpi/processor_idle.c:111