rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6000/1:b..l rcu: (detected by 1, t=10502 jiffies, g=7689, q=1251 ncpus=2) task:syz.4.12 state:R running task stack:26120 pid:6000 tgid:5983 ppid:5825 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x70 kernel/kcov.c:217 Code: a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 6c 16 00 00 85 c0 74 2b 8b 82 48 16 00 00 <83> f8 02 75 20 48 8b 8a 50 16 00 00 8b 92 4c 16 00 00 48 8b 01 48 RSP: 0018:ffffc90004bef508 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888024164582 RCX: ffffffff8b65dd38 RDX: ffff88802ef524c0 RSI: ffffffff8b65dd47 RDI: 0000000000000001 RBP: ffffc90004bef580 R08: 0000000000000001 R09: 000000000000003f R10: 0000000000000006 R11: 00000000f9f0d9a0 R12: 0000000000000225 R13: ffff888024164580 R14: 0000000000000006 R15: 0000000000000225 get_offset lib/xarray.c:147 [inline] xas_descend lib/xarray.c:207 [inline] xas_load+0x127/0x5b0 lib/xarray.c:246 filemap_get_entry+0x109/0x3b0 mm/filemap.c:1895 shmem_get_folio_gfp+0x221/0x1610 mm/shmem.c:2478 shmem_fault+0x1fe/0xa00 mm/shmem.c:2755 __do_fault+0x10d/0x490 mm/memory.c:5320 do_read_fault mm/memory.c:5755 [inline] do_fault+0xae4/0x1ce0 mm/memory.c:5889 do_pte_missing mm/memory.c:4401 [inline] handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault+0x1768/0x2cf0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x605/0x33a0 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x1d8/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3701 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f379438f749 RSP: 002b:00007f3795278038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f37945e6090 RCX: 00007f379438f749 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f3794413f91 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f37945e6128 R14: 00007f37945e6090 R15: 00007ffc8f958838 rcu: rcu_preempt kthread starved for 10322 jiffies! g7689 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:29112 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:clockevents_program_event+0x26e/0x370 kernel/time/clockevents.c:336 Code: 00 00 00 00 fc ff df 48 89 fa 48 d3 ed 48 c1 ea 03 80 3c 02 00 0f 85 f7 00 00 00 48 89 ef 48 89 de 48 8b 43 08 2e 2e 2e ff d0 <31> ff 89 c5 89 c6 e8 67 f5 0f 00 85 ed 74 2c e8 ae fa 0f 00 31 ff RSP: 0018:ffffc90000007e48 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880b8423f40 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 0000000000001e00 RDI: 0000000000000038 RBP: 0000000000001e00 R08: 0000000000000005 R09: 000000000000003f R10: 0000000000000020 R11: 0000000037609dba R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000020 R15: 000000295c2b4a00 FS: 0000000000000000(0000) GS:ffff888124956000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c572259ea0 CR3: 000000002888a000 CR4: 00000000003526f0 Call Trace: tick_program_event+0xa9/0x140 kernel/time/tick-oneshot.c:48 __hrtimer_reprogram kernel/time/hrtimer.c:678 [inline] __hrtimer_reprogram kernel/time/hrtimer.c:652 [inline] hrtimer_reprogram+0x27b/0x450 kernel/time/hrtimer.c:861 hrtimer_update_softirq_timer kernel/time/hrtimer.c:1207 [inline] hrtimer_run_softirq+0x262/0x350 kernel/time/hrtimer.c:1861 handle_softirqs+0x219/0x8b0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: e6 6e 02 c3 cc cc cc cc 0f 1f 00 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 65 22 00 fb f4 cc 2f 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 0000000000c4fae1 RBX: 0000000000000000 RCX: ffffffff8b67f6d9 RDX: 0000000000000000 RSI: ffffffff8dabfef6 RDI: ffffffff8bf22980 RBP: fffffbfff1c12f50 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: 00000000ffffffff R12: 0000000000000000 R13: ffffffff8e097a80 R14: ffffffff908743d0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4d0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148