rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5778/1:b..l rcu: (detected by 1, t=10502 jiffies, g=37405, q=129 ncpus=2) task:syz-executor state:R running task stack:20904 pid:5778 ppid:5773 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x30 kernel/rcu/update.c:318 Code: 73 04 04 00 75 e8 48 c7 c7 80 ca ca 8a 48 c7 c6 a0 ee ca 8a e8 31 ec c9 f6 0f 0b eb d1 cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1e fa 31 c0 83 3d 0f 40 04 04 00 74 1d 83 3d 86 73 04 04 00 RSP: 0018:ffffc900043d7630 EFLAGS: 00000282 RAX: 5d540ff604914700 RBX: ffffffff81ea42f2 RCX: 5d540ff604914700 RDX: 0000000000000000 RSI: ffffffff8acadd60 RDI: ffffffff8b1c9860 RBP: dffffc0000000000 R08: dffffc0000000000 R09: 1ffffffff2238ea0 R10: dffffc0000000000 R11: fffffbfff2238ea1 R12: 00fff00000000000 R13: dffffc0000000000 R14: ffffea00011e2000 R15: ffffea00011e2000 rcu_read_lock include/linux/rcupdate.h:787 [inline] page_ext_get+0x47/0x2b0 mm/page_ext.c:508 __page_table_check_zero+0x138/0x4b0 mm/page_table_check.c:148 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7c1/0x8c0 mm/page_alloc.c:2365 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2504 release_pages+0x1f7a/0x2200 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x630/0x1b20 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x245/0x9e0 mm/shmem.c:1264 evict+0x4ca/0x8d0 fs/inode.c:705 do_unlinkat+0x38c/0x590 fs/namei.c:4406 __do_sys_unlink fs/namei.c:4447 [inline] __se_sys_unlink fs/namei.c:4445 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4445 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8a1479bf47 RSP: 002b:00007ffdad4c84a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8a1479bf47 RDX: 00007ffdad4c84d0 RSI: 00007ffdad4c8560 RDI: 00007ffdad4c8560 RBP: 00007ffdad4c8560 R08: 00007ffdad4c9560 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffdad4c95f0 R13: 00007f8a148321ca R14: 00000000000947bf R15: 00007ffdad4c9630 rcu: rcu_preempt kthread starved for 10536 jiffies! g37405 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:26568 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: b9 20 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d c3 54 41 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6 RAX: a840d729b33e8e00 RBX: ffffffff8162aee1 RCX: a840d729b33e8e00 RDX: 0000000000000001 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9860 RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65 R10: dffffc0000000000 R11: ffffed10171e6d66 R12: 1ffff92000030fc8 R13: dffffc0000000000 R14: 1ffff110036cd780 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2092185fc0 CR3: 0000000031319000 CR4: 00000000003506e0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:178 [inline] do_idle+0x221/0x590 kernel/sched/idle.c:302 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b