rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5630/1:b..l P7521/1:b..l rcu: (detected by 0, t=10502 jiffies, g=30581, q=1275 ncpus=2) task:syz.1.381 state:R running task stack:25864 pid:7521 tgid:7520 ppid:5607 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] finish_fault+0xf7a/0x1220 mm/memory.c:5730 do_read_fault mm/memory.c:5864 [inline] do_fault mm/memory.c:5994 [inline] do_pte_missing+0x223d/0x34b0 mm/memory.c:4566 handle_pte_fault mm/memory.c:6379 [inline] __handle_mm_fault mm/memory.c:6517 [inline] handle_mm_fault+0x1b36/0x3080 mm/memory.c:6686 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1678/0x2720 mm/gup.c:1428 populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860 __mm_populate+0x25f/0x390 mm/gup.c:1963 mm_populate include/linux/mm.h:4171 [inline] vm_mmap_pgoff+0x353/0x4e0 mm/util.c:586 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe72999e0d9 RSP: 002b:00007fe72a783028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fe729c25fa0 RCX: 00007fe72999e0d9 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fe729a35024 R08: ffffffffffffffff R09: 000000001b5cb000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe729c26038 R14: 00007fe729c25fa0 R15: 00007ffcd87fe078 task:syz-executor state:R running task stack:22408 pid:5630 tgid:5630 ppid:5605 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:xa_is_internal include/linux/xarray.h:175 [inline] RIP: 0010:xa_is_sibling include/linux/xarray.h:1293 [inline] RIP: 0010:xas_reload+0x1d9/0x470 include/linux/xarray.h:1625 Code: 01 00 00 e8 c9 f2 c0 ff 48 bd 00 00 00 00 00 fc ff df 41 89 dc 41 83 e4 03 bf 02 00 00 00 4c 89 e6 e8 8b f7 c0 ff 49 83 fc 02 <0f> 94 c0 48 81 fb fe 00 00 00 0f 92 c1 84 c1 0f 84 91 00 00 00 c1 RSP: 0018:ffffc90002e1f508 EFLAGS: 00000293 RAX: ffffffff82060eb5 RBX: ffffea0000f566c0 RCX: ffff888012281f00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: dffffc0000000000 R08: ffffea0000f566f7 R09: 1ffffd40001eacde R10: dffffc0000000000 R11: fffff940001eacdf R12: 0000000000000000 R13: 1ffff920005c3ebc R14: ffffc90002e1f5e0 R15: ffff8880541918c0 find_get_entry mm/filemap.c:2102 [inline] find_lock_entries+0x483/0xad0 mm/filemap.c:2189 shmem_undo_range+0x2c7/0x15d0 mm/shmem.c:1141 shmem_truncate_range mm/shmem.c:1287 [inline] shmem_evict_inode+0x280/0xa80 mm/shmem.c:1417 evict+0x624/0xb50 fs/inode.c:825 dentry_kill+0x1b9/0x880 fs/dcache.c:826 finish_dput+0x1a/0x260 fs/dcache.c:1001 __fput+0x675/0xa50 fs/file_table.c:520 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f73f115e90e RSP: 002b:00007fff3e851448 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000555588075500 RCX: 00007f73f115e90e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fff3e8514ec R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000003a R13: 00000000000927c0 R14: 000000000004569c R15: 00007fff3e851540 rcu: rcu_preempt kthread starved for 10595 jiffies! g30581 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 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 07/16/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: bb 7e 02 e9 9e 8f 3f f5 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 b3 be 18 00 fb f4 77 8f 3f f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e807de0 EFLAGS: 00000242 RAX: 0000000000fb9cb3 RBX: ffffffff819b4450 RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8e228abd RDI: ffffffff8c4bbe80 RBP: ffffffff8e807eb8 R08: ffff8880b86338db R09: 1ffff110170c671b R10: dffffc0000000000 R11: ffffed10170c671c R12: 0000000000000000 R13: 1ffffffff1d11de8 R14: 1ffffffff1d00fc4 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888124f55000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2feba15338 CR3: 0000000077b7a000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x2e0/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 rest_init+0x2de/0x300 init/main.c:717 start_kernel+0x392/0x3e0 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x157