rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6217/1:b..l rcu: (detected by 0, t=10502 jiffies, g=22865, q=865 ncpus=1) task:syz.1.113 state:R running task stack:22984 pid:6217 tgid:6217 ppid:5604 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7592 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa10 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5913 Code: 05 4f cd a4 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 5e da 5d 0f 0f 82 c9 02 00 00 8b 35 fe 0b 5e 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 ed cc a4 12 0f 85 09 03 00 00 48 83 c4 RSP: 0018:ffffc90004e26ea8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e3c4c52 RDI: ffffffff8c620e80 RBP: ffffffff8edec060 R08: 00000000ef9d33e4 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] class_rcu_constructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:183 __reset_page_owner+0x84/0x190 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] free_unref_folios+0xa4a/0x1790 mm/page_alloc.c:3022 folios_put_refs+0x585/0xaa0 mm/folio.c:1034 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1161 shmem_truncate_range mm/shmem.c:1289 [inline] shmem_evict_inode+0x3b1/0xca0 mm/shmem.c:1420 evict+0x3c2/0xad0 fs/inode.c:822 iput_final fs/inode.c:2015 [inline] iput.part.0+0x989/0x1050 fs/inode.c:2064 iput+0x35/0x40 fs/inode.c:2030 dentry_unlink_inode+0x284/0x470 fs/dcache.c:479 dentry_kill+0x25d/0xc20 fs/dcache.c:826 finish_dput fs/dcache.c:1001 [inline] dput.part.0+0xd7/0x240 fs/dcache.c:1042 dput+0x1f/0x30 fs/dcache.c:1037 __fput+0x519/0xb50 fs/file_table.c:520 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x951/0x2ae0 kernel/exit.c:1008 do_group_exit+0xd5/0x2a0 kernel/exit.c:1151 get_signal+0x1ec7/0x21e0 kernel/signal.c:3039 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop kernel/entry/common.c:101 [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:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x402/0xa10 kernel/entry/common.c:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fab76453bd7 RSP: 002b:00007fab774be1a0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fab7659e159 RDX: 00007fab774be1c0 RSI: 00007fab774be2f0 RDI: 000000000000000b RBP: 00007fab76635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fab76826038 R14: 00007fab76825fa0 R15: 00007ffe5736b6c8 rcu: rcu_preempt kthread starved for 10502 jiffies! g22865 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:28984 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7362 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 6395 Comm: syz.0.164 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:220 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:229 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 2a de 14 f6 48 89 df e8 52 34 15 f6 e8 7d f4 41 f6 fb bf 01 00 00 00 32 3b 04 f6 65 48 83 3d f1 a5 b9 08 00 74 06 5b c3 cc cc cc cc RSP: 0018:ffffc90003857c90 EFLAGS: 00000206 RAX: 000000000953c22d RBX: ffff888021fe9280 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff8e3eb021 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000021 R13: ffff888021fe9680 R14: dffffc0000000000 R15: ffff88802b3b8000 FS: 00007febc1c2a6c0(0000) GS:ffff888123b61000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33004ff8 CR3: 000000002ce6b000 CR4: 00000000003526f0 Call Trace: spin_unlock_irq include/linux/spinlock.h:413 [inline] get_signal+0x195a/0x21e0 kernel/signal.c:3042 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x700 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:336 [inline] do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7febc0d9e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007febc1c2a0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007febc1025fa8 RCX: 00007febc0d9e159 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007febc1025fa8 RBP: 00007febc1025fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007febc1026038 R14: 00007ffd96e435f0 R15: 00007ffd96e436d8