rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8357/1:b..l rcu: (detected by 0, t=10502 jiffies, g=32541, q=703 ncpus=2) task:syz.2.589 state:R running task stack:26712 pid:8357 tgid:8352 ppid:5821 task_flags:0x40044c flags:0x00080001 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:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872 Code: 2f 12 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 e2 93 ed 0e 0f 82 74 02 00 00 8b 35 5a c4 ed 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 f9 2e 12 12 0f 85 ad 02 00 00 48 83 c4 RSP: 0018:ffffc90003566e68 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c92c0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8da9585e RDI: ffffffff8bf21180 RBP: 0000000000000002 R08: 000000005a44979c R09: 00000000ffffffff R10: ffff88802c0ad4b0 R11: 00000000ffffffff R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:311 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xa15/0x1600 mm/page_alloc.c:2958 folios_put_refs+0x4be/0x750 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x58f/0x1140 mm/shmem.c:1119 shmem_truncate_range mm/shmem.c:1231 [inline] shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1359 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:467 __dentry_kill+0x1d0/0x600 fs/dcache.c:670 dput.part.0+0x4b1/0x9b0 fs/dcache.c:912 dput+0x1f/0x30 fs/dcache.c:902 __fput+0x51c/0xb70 fs/file_table.c:476 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x87f/0x2bd0 kernel/exit.c:973 do_group_exit+0xd3/0x2a0 kernel/exit.c:1114 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f30ca38f749 RSP: 002b:00007f30cb2ad038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007f30ca5e6090 RCX: 00007f30ca38f749 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000006 RBP: 00007f30ca413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f30ca5e6128 R14: 00007f30ca5e6090 R15: 00007ffd49039838 rcu: rcu_preempt kthread starved for 10553 jiffies! g32541 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:28456 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8363 Comm: syz.7.590 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x26/0x60 kernel/locking/spinlock.c:162 Code: 90 90 90 90 f3 0f 1e fa 55 53 48 89 fb 9c 5d fa f7 c5 00 02 00 00 75 39 bf 01 00 00 00 e8 52 2b 22 f6 ff 74 24 10 48 8d 7b 18 <45> 31 c9 31 c9 41 b8 01 00 00 00 31 d2 31 f6 e8 26 52 31 f6 48 89 RSP: 0018:ffffc90000a08f10 EFLAGS: 00000097 RAX: 0000000000010002 RBX: ffff8880b8528340 RCX: 1ffffffff3575e50 RDX: 0000000000000000 RSI: ffffffff81aa4068 RDI: ffff8880b8528358 RBP: 0000000000000046 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffffc90000a08ff8 R12: ffff8880b85284a0 R13: ffff8880b852838c R14: 0000000000000000 R15: ffff8880b8528340 FS: 0000555590186500(0000) GS:ffff888124a68000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f930318bb4c CR3: 0000000067829000 CR4: 00000000003526f0 Call Trace: hrtimer_interrupt+0x10e/0x8e0 kernel/time/hrtimer.c:1884 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 4a 49 31 f6 48 89 df e8 c2 9c 31 f6 e8 2d 04 5e f6 fb bf 01 00 00 00 02 b7 21 f6 65 8b 05 2b 7f 43 08 85 c0 74 06 5b e9 51 4c 00 00 RSP: 0018:ffffc90003657ca0 EFLAGS: 00000206 RAX: 0000000009f6931b RBX: ffff88801eb48000 RCX: ffffffff81c6042f RDX: 0000000000000000 RSI: ffffffff8dabb765 RDI: 0000000000000001 RBP: ffff88801eb48200 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9086e4d7 R11: 00000000ffffffff R12: 0000000000000000 R13: 0000000000000011 R14: 0000000000000200 R15: ffff88801eb48000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1e6a/0x26d0 kernel/signal.c:3037 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f67d8f8f783 Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7 RSP: 002b:00007fffa2f47548 EFLAGS: 00000246 RAX: 00007f67d9e15000 RBX: 00007f67d79f76c0 RCX: 00007f67d8f8f783 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007fffa2f476a0 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000