rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6154/1:b..l rcu: (detected by 0, t=10502 jiffies, g=12677, q=1060 ncpus=2) task:syz.1.49 state:R running task stack:25896 pid:6154 tgid:6150 ppid:5821 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x17df/0x2390 arch/x86/kernel/unwind_orc.c:664 Code: 24 48 01 c6 4c 89 f7 48 89 da e8 4c 0e 00 00 84 c0 0f 84 47 01 00 00 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 20 0f b6 04 28 <84> c0 0f 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 39 06 4c 8b RSP: 0018:ffffc9000b5c6d38 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff90165942 RCX: 0000000000000001 RDX: ffffc9000b5c6e48 RSI: dffffc0000000000 RDI: ffffc9000b5c7850 RBP: dffffc0000000000 R08: ffffc9000b5c7850 R09: ffffc9000b5c6e58 R10: dffffc0000000000 R11: fffff520016b8dcd R12: ffffc9000b5c7850 R13: ffffc9000b5c6e58 R14: ffffc9000b5c6e08 R15: 1ffffffff202cb28 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:332 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2435 shmem_alloc_folio mm/shmem.c:1871 [inline] shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1910 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2533 shmem_fault+0x179/0x390 mm/shmem.c:2734 __do_fault+0x138/0x390 mm/memory.c:5280 do_read_fault mm/memory.c:5698 [inline] do_fault mm/memory.c:5832 [inline] do_pte_missing mm/memory.c:4361 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x35e3/0x5400 mm/memory.c:6318 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x165c/0x2a00 mm/gup.c:1428 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860 __mm_populate+0x24c/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3471 [inline] vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb2fa18efc9 RSP: 002b:00007fb2fb066038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fb2fa3e5fa0 RCX: 00007fb2fa18efc9 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fb2fa211f91 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb2fa3e6038 R14: 00007fb2fa3e5fa0 R15: 00007fffa4891fc8 rcu: rcu_preempt kthread starved for 10557 jiffies! g12677 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245