rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23250/3:b..l P23044/1:b..l rcu: (detected by 1, t=10502 jiffies, g=152617, q=756 ncpus=2) task:syz.2.4226 state:R running task stack:21464 pid:23044 tgid:23044 ppid:20851 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x44/0x3c0 kernel/locking/lockdep.c:5879 Code: 8b 05 50 50 97 11 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 53 50 97 11 83 f8 08 0f 83 56 02 00 00 89 c0 48 0f a3 05 fc cd 8e 0e <73> 0d e8 45 f7 08 00 84 c0 0f 84 94 02 00 00 83 3d b6 00 8f 0e 00 RSP: 0018:ffffc9000465ed50 EFLAGS: 00000297 RAX: 0000000000000001 RBX: ffffffff90c5b701 RCX: 0000000080000001 RDX: ffffc9000465ee01 RSI: ffffffff8176f256 RDI: ffffffff8e95cd60 RBP: dffffc0000000000 R08: ffffc9000465fcc0 R09: ffffc9000465eed8 R10: dffffc0000000000 R11: fffff520008cbddd R12: ffffc9000465fcd0 R13: ffffffff8176f256 R14: ffffffff8e95cd60 R15: ffffffff8176f256 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] free_unref_folios+0xcec/0x1480 mm/page_alloc.c:3004 folios_put_refs+0x9ff/0xb40 mm/swap.c:1008 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x289/0xae0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:841 __dentry_kill+0x1a2/0x690 fs/dcache.c:718 finish_dput+0xc9/0x480 fs/dcache.c:927 __fput+0x691/0xa60 fs/file_table.c:518 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline] irqentry_exit+0x284/0x730 kernel/entry/common.c:162 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x0 RSP: 002b:00002000000000b8 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fd04e215fa0 RCX: 00007fd04df9cdd9 RDX: 00002000000000c0 RSI: 00002000000000b0 RDI: 0000000040000000 RBP: 00007fd04e032d69 R08: 00002000000002c0 R09: 00002000000002c0 R10: 0000200000000100 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fd04e216038 R14: 00007fd04e215fa0 R15: 00007fff46c0f088 task:modprobe state:R running task stack:25288 pid:23250 tgid:23250 ppid:37 task_flags:0x400000 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 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] filemap_map_pages+0x1a2a/0x2100 mm/filemap.c:3942 do_fault_around mm/memory.c:5851 [inline] do_read_fault mm/memory.c:5884 [inline] do_fault mm/memory.c:6027 [inline] do_pte_missing+0x1f38/0x33f0 mm/memory.c:4550 handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x1bd7/0x3170 mm/memory.c:6718 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f9a40d334c0 RSP: 002b:00007fff12382708 EFLAGS: 00010246 RAX: 0000000000000001 RBX: 00007f9a40d2fb20 RCX: 00007f9a40d46300 RDX: 0000000000000000 RSI: 0000000000001430 RDI: 0000000000000000 RBP: 00007fff123827f0 R08: 00007f9a40d47730 R09: 0000000000000000 R10: 0000000000000009 R11: 00007fff123821e0 R12: 0000000000000025 R13: 00007f9a40d48da0 R14: 0000000000000000 R15: 00007f9a40d13000 rcu: rcu_preempt kthread starved for 10327 jiffies! g152617 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:28096 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 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: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: bb 7d 02 e9 fe 9f 67 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 53 c1 20 00 fb f4 d7 9f 67 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000242 RAX: 000000000234b849 RBX: ffffffff819a91ea RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dfa6610 RDI: ffffffff8c28ade0 RBP: ffffc90000197f10 R08: ffff8880b87339db R09: 1ffff110170e673b R10: dffffc0000000000 R11: ffffed10170e673c R12: 0000000000000001 R13: 1ffff11003b54000 R14: 0000000000000001 R15: 1ffff11003b54000 FS: 0000000000000000(0000) GS:ffff88812538d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2966fa CR3: 0000000032816000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147