rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5803/1:b..l P5811/1:b..l P5814/1:b..l rcu: (detected by 0, t=10502 jiffies, g=108317, q=195 ncpus=2) task:syz-executor state:R running task stack:23384 pid:5814 tgid:5814 ppid:5800 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0x14f0/0x1ea0 arch/x86/kernel/unwind_orc.c:663 Code: 84 d2 0f 95 c0 40 84 c6 0f 85 cb 05 00 00 48 0f bf 69 02 ba 08 00 00 00 4c 89 ef 4d 8d 7d 34 4c 01 f5 48 89 ee e8 30 e9 ff ff <84> c0 0f 84 54 ee ff ff 48 89 ef e8 00 e3 ff ff 49 8d 7d 40 48 89 RSP: 0018:ffffc90003c27320 EFLAGS: 00000282 RAX: ffffc90003c28001 RBX: 0000000000000001 RCX: ffffffff922c9934 RDX: ffffc90003c27f01 RSI: ffffc90003c27f38 RDI: ffffc90003c273a0 RBP: ffffc90003c27f38 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 00000000000a8f51 R12: ffffc90003c273e0 R13: ffffc90003c27390 R14: ffffc90003c27f48 R15: ffffc90003c273c4 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:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xaea/0x1790 mm/page_alloc.c:3040 folios_put_refs+0x53c/0x840 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x39e/0xbd0 mm/shmem.c:1407 evict+0x3c2/0xad0 fs/inode.c:846 iput_final fs/inode.c:1966 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2015 iput+0x35/0x40 fs/inode.c:1981 filename_unlinkat+0x466/0x730 fs/namei.c:5544 __do_sys_unlink fs/namei.c:5575 [inline] __se_sys_unlink fs/namei.c:5572 [inline] __x64_sys_unlink+0x46/0x70 fs/namei.c:5572 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f682939b887 RSP: 002b:00007ffddf4338e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f682939b887 RDX: 00007ffddf433910 RSI: 00007ffddf4339a0 RDI: 00007ffddf4339a0 RBP: 00007ffddf4339a0 R08: 00007ffddf4349a0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffddf434a30 R13: 00007f6829432050 R14: 000000000015498c R15: 00007ffddf434a70 task:syz-executor state:R running task stack:24120 pid:5811 tgid:5811 ppid:5799 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5872 Code: 05 fb cd 28 12 83 f8 07 0f 87 f0 00 00 00 48 0f a3 05 c6 aa f4 0e 0f 82 c2 02 00 00 8b 35 ae de f4 0e 85 f6 0f 85 dd 00 00 00 <48> 8b 44 24 30 65 48 2b 05 9d cd 28 12 0f 85 02 03 00 00 48 83 c4 RSP: 0018:ffffc90003bf72a8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8de502df RDI: ffffffff8c1b0420 RBP: ffffffff8e7e75a0 R08: 00000000624db722 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xd1/0x1ea0 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:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xaea/0x1790 mm/page_alloc.c:3040 folios_put_refs+0x53c/0x840 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x39e/0xbd0 mm/shmem.c:1407 evict+0x3c2/0xad0 fs/inode.c:846 iput_final fs/inode.c:1966 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2015 iput+0x35/0x40 fs/inode.c:1981 filename_unlinkat+0x466/0x730 fs/namei.c:5544 __do_sys_unlink fs/namei.c:5575 [inline] __se_sys_unlink fs/namei.c:5572 [inline] __x64_sys_unlink+0x46/0x70 fs/namei.c:5572 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f49a979b887 RSP: 002b:00007ffcc0a22508 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f49a979b887 RDX: 00007ffcc0a22530 RSI: 00007ffcc0a225c0 RDI: 00007ffcc0a225c0 RBP: 00007ffcc0a225c0 R08: 00007ffcc0a235c0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffcc0a23650 R13: 00007f49a9832050 R14: 0000000000154689 R15: 00007ffcc0a23690 task:syz-executor state:R running task stack:23128 pid:5803 tgid:5803 ppid:5798 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7092 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+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:389 [inline] copy_pte_range mm/memory.c:1344 [inline] copy_pmd_range mm/memory.c:1405 [inline] copy_pud_range mm/memory.c:1442 [inline] copy_p4d_range mm/memory.c:1466 [inline] copy_page_range+0x1e72/0x6570 mm/memory.c:1552 dup_mmap+0xd25/0x2180 mm/mmap.c:1841 dup_mm kernel/fork.c:1530 [inline] copy_mm kernel/fork.c:1582 [inline] copy_process+0x73d7/0x7a10 kernel/fork.c:2223 kernel_clone+0xfc/0x9a0 kernel/fork.c:2654 __do_sys_clone+0xd9/0x120 kernel/fork.c:2795 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f97209c5212 RSP: 002b:00007ffe7f9e2c70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe7f9e2c70 RCX: 00007f97209c5212 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe7f9e2dfc R08: 0000000000000000 R09: 0000000000000001 R10: 0000555555fac7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000154e8a R15: 00007ffe7f9e2e50 rcu: rcu_preempt kthread starved for 10553 jiffies! g108317 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:27832 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 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 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: a8 82 02 c3 cc cc cc cc 0f 1f 00 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 03 a1 1b 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e407e00 EFLAGS: 00000246 RAX: 0000000007dee86f RBX: ffffffff8e4975c0 RCX: ffffffff8b8fec75 RDX: 0000000000000000 RSI: ffffffff8de763db RDI: ffffffff8c1b0420 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1017086795 R10: ffff8880b8433cab R11: 0000000000000000 R12: fffffbfff1c92eb8 R13: 0000000000000000 R14: ffffffff90d98d10 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124345000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000453000 CR3: 0000000097bf3000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x43a/0x550 kernel/sched/idle.c:341 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:439 rest_init+0x251/0x260 init/main.c:760 start_kernel+0x47f/0x480 init/main.c:1210 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148