rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10922/1:b..l rcu: (detected by 0, t=10502 jiffies, g=36765, q=347 ncpus=2) task:syz.9.1151 state:R running task stack:23400 pid:10922 tgid:10922 ppid:9513 task_flags:0x40064c 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:orc_find arch/x86/kernel/unwind_orc.c:220 [inline] RIP: 0010:unwind_next_frame+0x2bb/0x20a0 arch/x86/kernel/unwind_orc.c:494 Code: 20 44 8b 5c 24 18 89 cf 8b 14 95 ec 93 dc 91 48 8d 04 7f 48 8d 84 00 f4 a2 1a 91 83 c2 01 48 3d ec 93 dc 91 0f 83 4d 08 00 00 <41> 89 d0 4f 8d 04 40 4f 8d 84 00 f4 a2 1a 91 49 81 f8 ec 93 dc 91 RSP: 0018:ffffc9000527ef38 EFLAGS: 00000293 RAX: ffffffff91261306 RBX: 0000000000000001 RCX: 000000000001e803 RDX: 000000000001e80d RSI: 00000000000a7c05 RDI: 000000000001e803 RBP: ffffc9000527eff0 R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000002 R11: 000000000000a961 R12: ffffc9000527eff8 R13: ffffc9000527efa8 R14: ffffc9000527efdd R15: ffffffff81a9616d arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] free_unref_folios+0xa22/0x1610 mm/page_alloc.c:3000 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:1137 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x39e/0xbe0 mm/shmem.c:1379 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 finish_dput+0x76/0x480 fs/dcache.c:879 dput.part.0+0x451/0x570 fs/dcache.c:928 dput+0x1f/0x30 fs/dcache.c:920 __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:971 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 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 kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x38a/0x8c0 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x0 RSP: 002b:0000200000000708 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007ff1e13e6180 RCX: 00007ff1e118f749 RDX: 0000000000000000 RSI: 0000200000000700 RDI: 0000000006004400 RBP: 00007ff1e1213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff1e13e6218 R14: 00007ff1e13e6180 R15: 00007ffe8d72fd88 rcu: rcu_preempt kthread starved for 10456 jiffies! g36765 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:27992 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: 11042 Comm: syz.8.1184 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:__lock_acquire+0xbc6/0x2890 kernel/locking/lockdep.c:5233 Code: 8b 4c 24 08 4c 8b 5c 24 10 85 c0 0f 85 f8 f7 ff ff e9 e1 f8 ff ff 41 0f b7 46 f8 66 25 ff 1f 0f b7 c0 48 0f a3 05 aa a2 1f 14 <0f> 83 56 08 00 00 48 8d 04 80 48 8d 04 80 48 8d 04 c5 60 7a b9 95 RSP: 0018:ffffc9000477f938 EFLAGS: 00000003 RAX: 0000000000000937 RBX: 0000000000000000 RCX: 00000000bf91ebc4 RDX: 000000000000092f RSI: 0000000000000000 RDI: ffff888027fe0000 RBP: 0000000000000001 R08: 00000000aa8cfb84 R09: 000000004aa8cfb8 R10: 0000000000000002 R11: ffff888027fe0b30 R12: ffff888027fe0000 R13: 0000000000000000 R14: ffff888027fe0b58 R15: 4aa8cfb8bf91ebc4 FS: 00007f0f634df6c0(0000) GS:ffff8881249f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000035b1f000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 srcu_lock_acquire include/linux/srcu.h:185 [inline] srcu_read_lock include/linux/srcu.h:277 [inline] kvm_vcpu_srcu_read_lock include/linux/kvm_host.h:963 [inline] vcpu_enter_guest arch/x86/kvm/x86.c:11448 [inline] vcpu_run+0x3329/0x5a80 arch/x86/kvm/x86.c:11632 kvm_arch_vcpu_ioctl_run+0xfd3/0x1860 arch/x86/kvm/x86.c:11977 kvm_vcpu_ioctl+0x76d/0x16d0 virt/kvm/kvm_main.c:4477 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 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: 0033:0x7f0f6258f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0f634df038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0f627e5fa0 RCX: 00007f0f6258f749 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000008 RBP: 00007f0f62613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0f627e6038 R14: 00007f0f627e5fa0 R15: 00007ffc6aff13b8