rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3756/1:b..l P3806/1:b..l P3810/1:b..l (detected by 0, t=10502 jiffies, g=7009, q=21 ncpus=2) task:syz.2.18 state:R running task stack:21688 pid:3810 ppid:3799 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] filemap_map_pages+0xffa/0x12c0 mm/filemap.c:3470 do_fault_around mm/memory.c:4581 [inline] do_read_fault mm/memory.c:4607 [inline] do_fault mm/memory.c:4741 [inline] handle_pte_fault mm/memory.c:5012 [inline] __handle_mm_fault mm/memory.c:5154 [inline] handle_mm_fault+0x33e0/0x5340 mm/memory.c:5275 faultin_page mm/gup.c:1009 [inline] __get_user_pages+0x4f3/0x1190 mm/gup.c:1233 __get_user_pages_locked mm/gup.c:1437 [inline] get_dump_page+0x1ad/0x8a0 mm/gup.c:1935 dump_user_range+0x111/0x8e0 fs/coredump.c:906 elf_core_dump+0x3d2b/0x4590 fs/binfmt_elf.c:2313 do_coredump+0x18b7/0x2700 fs/coredump.c:755 get_signal+0x1454/0x17d0 kernel/signal.c:2856 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x1c0/0x620 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7fef06040397 RSP: 002b:00007fef06f88120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fef0617def9 RDX: 00007fef06f88140 RSI: 00007fef06f88270 RDI: 000000000000000b RBP: 00007fef061f0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fef06336130 R15: 00007ffdae1ea718 task:syz.3.21 state:R running task stack:25016 pid:3806 ppid:3638 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 unwind_next_frame+0x1a55/0x2220 arch/x86/kernel/unwind_orc.c:629 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x52/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1444 [inline] free_pcp_prepare mm/page_alloc.c:1494 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3510 release_pages+0x2836/0x2b40 mm/swap.c:1055 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261 zap_pte_range mm/memory.c:1525 [inline] zap_pmd_range mm/memory.c:1574 [inline] zap_pud_range mm/memory.c:1603 [inline] zap_p4d_range mm/memory.c:1624 [inline] unmap_page_range+0x217c/0x2740 mm/memory.c:1645 unmap_vmas+0x48b/0x640 mm/memory.c:1730 exit_mmap+0x252/0x9f0 mm/mmap.c:3227 __mmput+0x115/0x3c0 kernel/fork.c:1199 exit_mm+0x226/0x300 kernel/exit.c:565 do_exit+0x9f6/0x26a0 kernel/exit.c:858 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 get_signal+0x16f7/0x17d0 kernel/signal.c:2870 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f951e57def9 RSP: 002b:00007f951f28f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: 00000000005f7b80 RBX: 00007f951e735f80 RCX: 00007f951e57def9 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 0000000000000015 RBP: 00007f951e5f0b76 R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f951e735f80 R15: 00007ffe0e71da98 task:syz.1.2 state:R running task stack:21592 pid:3756 ppid:3635 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:lock_is_held_type+0x137/0x180 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90004646530 EFLAGS: 00000206 RAX: da8a849b4903e500 RBX: 0000000000000002 RCX: 0000000080000000 RDX: ffff88802e609dc0 RSI: ffffffff8b0c14c0 RDI: ffffffff8b5d6dc0 RBP: 0000000000000001 R08: ffffffff8aa302f9 R09: fffffbfff223b845 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246 R13: ffff88802e609dc0 R14: 00000000ffffffff R15: ffffffff8d32b000 xa_entry include/linux/xarray.h:1198 [inline] xas_descend+0x120/0x470 lib/xarray.c:204 xas_load lib/xarray.c:242 [inline] xa_load+0x288/0x480 lib/xarray.c:1463 __readahead_folio include/linux/pagemap.h:1287 [inline] readahead_page include/linux/pagemap.h:1305 [inline] ext4_mpage_readpages+0x49d/0x2eb0 fs/ext4/readpage.c:256 read_pages+0x17f/0x830 mm/readahead.c:161 page_cache_ra_unbounded+0x68b/0x7b0 mm/readahead.c:270 do_async_mmap_readahead mm/filemap.c:3135 [inline] filemap_fault+0x797/0x17e0 mm/filemap.c:3189 __do_fault+0x136/0x4f0 mm/memory.c:4261 do_read_fault mm/memory.c:4612 [inline] do_fault mm/memory.c:4741 [inline] handle_pte_fault mm/memory.c:5012 [inline] __handle_mm_fault mm/memory.c:5154 [inline] handle_mm_fault+0x3410/0x5340 mm/memory.c:5275 faultin_page mm/gup.c:1009 [inline] __get_user_pages+0x4f3/0x1190 mm/gup.c:1233 __get_user_pages_locked mm/gup.c:1437 [inline] get_dump_page+0x1ad/0x8a0 mm/gup.c:1935 dump_user_range+0x111/0x8e0 fs/coredump.c:906 elf_core_dump+0x3d2b/0x4590 fs/binfmt_elf.c:2313 do_coredump+0x18b7/0x2700 fs/coredump.c:755 get_signal+0x1454/0x17d0 kernel/signal.c:2856 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x1c0/0x620 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7fa4dc040397 RSP: 002b:00007fa4dd034120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fa4dc17def9 RDX: 00007fa4dd034140 RSI: 00007fa4dd034270 RDI: 000000000000000b RBP: 00007fa4dc1f0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa4dc335f80 R15: 00007ffeb9f08858 rcu: rcu_preempt kthread starved for 10635 jiffies! g7009 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:26144 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567 sched: RT throttling activated