rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10077/1:b..l rcu: (detected by 1, t=10502 jiffies, g=42241, q=317 ncpus=2) task:syz.6.1042 state:R running task stack:25576 pid:10077 tgid:10056 ppid:8895 task_flags:0x400140 flags:0x00080002 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:deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] RIP: 0010:unwind_next_frame+0xc3c/0x2390 arch/x86/kernel/unwind_orc.c:585 Code: 3c 01 0f 85 f9 0c 00 00 48 8d 43 08 4c 39 f8 0f 97 c1 4c 39 e0 0f 96 c0 20 c8 3c 01 0f 85 df 0c 00 00 48 89 df e8 84 23 00 00 <48> 89 c3 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 RSP: 0018:ffffc9001304ebf8 EFLAGS: 00000202 RAX: ffffffff8222ed42 RBX: ffffc9001304f3b8 RCX: 1ffff92002609d01 RDX: ffffffff9038f4fa RSI: 0000000000000002 RDI: ffffc9001304f3b8 RBP: 1ffff92002609d9a R08: 0000000000000001 R09: ffffffff8173cd25 R10: ffffc9001304ed18 R11: ffffffff81ac8570 R12: ffffc90013050000 R13: 1ffff92002609d9b R14: ffffc9001304ecc8 R15: ffffc90013048000 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:165 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341 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:2418 alloc_frozen_pages_noprof mm/mempolicy.c:2489 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2509 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2519 filemap_alloc_folio_noprof+0x112/0x490 mm/filemap.c:1025 filemap_create_folio mm/filemap.c:2560 [inline] filemap_get_pages+0x780/0x1df0 mm/filemap.c:2650 filemap_splice_read+0x581/0xc60 mm/filemap.c:3033 do_splice_read fs/splice.c:982 [inline] splice_direct_to_actor+0x4a9/0xcc0 fs/splice.c:1086 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x181/0x270 fs/splice.c:1230 do_sendfile+0x4da/0x7e0 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1431 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417 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: 0033:0x7f6860f8eec9 RSP: 002b:00007f685f1d5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f68611e6180 RCX: 00007f6860f8eec9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000008 RBP: 00007f6861011f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0001000000201005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f68611e6218 R14: 00007f68611e6180 R15: 00007ffd7a1916e8 rcu: rcu_preempt kthread starved for 9755 jiffies! g42241 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: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 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 b1 19 00 f3 0f 1e fa fb f4 48 e7 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0000:ffffc90000197de0 EFLAGS: 000002c6 RAX: 1b202e5ec6852400 RBX: ffffffff8196d367 RCX: 1b202e5ec6852400 RDX: 0000000000000001 RSI: ffffffff8d7eeef8 RDI: ffffffff8bc07ce0 RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8f9e3170 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d3b58 FS: 0000000000000000(0000) GS:ffff888125e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb4a20e7001 CR3: 000000005f96a000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147