rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7781/1:b..l rcu: (detected by 1, t=10502 jiffies, g=27913, q=883 ncpus=2) task:syz.4.520 state:R running task stack:25776 pid:7781 tgid:7780 ppid:5086 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 0a 84 89 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000480f260 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000901e58 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaccc0 RDI: ffffffff8c202900 RBP: ffffc9000480f3b8 R08: ffffffff92fad587 R09: 1ffffffff25f5ab0 R10: dffffc0000000000 R11: fffffbfff25f5ab1 R12: 1ffff92000901e54 R13: dffffc0000000000 R14: ffffc9000480f2c0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:521 __page_table_check_zero+0xb1/0x350 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:1094 [inline] free_unref_folios+0xf37/0x19e0 mm/page_alloc.c:2637 folios_put_refs+0x93a/0xa60 mm/swap.c:1024 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:329 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 unmap_region+0x2df/0x350 mm/mmap.c:2370 do_vmi_align_munmap+0x1122/0x18c0 mm/mmap.c:2683 do_vmi_munmap+0x261/0x2f0 mm/mmap.c:2759 __vm_munmap+0x1fc/0x400 mm/mmap.c:3038 __do_sys_munmap mm/mmap.c:3055 [inline] __se_sys_munmap mm/mmap.c:3052 [inline] __x64_sys_munmap+0x68/0x80 mm/mmap.c:3052 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7930b75c67 RSP: 002b:00007f79319dbe28 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f7930b75c67 RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007f7926800000 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000609b R10: 0000000000000772 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f79319dbf00 R14: 00007f79319dbec0 R15: 00007f7926800000 rcu: rcu_preempt kthread starved for 10323 jiffies! g27913 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:25328 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.10.0-rc7-syzkaller-00266-g4d145e3f830b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 c0 d4 03 00 48 f7 00 08 00 00 00 75 10 eb 07 0f 00 2d 35 2a a3 00 f3 0f 1e fa fb f4 e9 d4 b3 29 00 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d08 EFLAGS: 00000246 RAX: ffff888017ae0000 RBX: ffff88801ae84864 RCX: 0000000000285c11 RDX: 0000000000000001 RSI: ffff88801ae84800 RDI: ffff88801ae84864 RBP: 000000000003a578 R08: ffff8880b9537ccb R09: 1ffff110172a6f99 R10: dffffc0000000000 R11: ffffffff8b8688e0 R12: ffff88801c358000 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8ead1560 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020048000 CR3: 000000002a354000 CR4: 0000000000350ef0 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x114/0x480 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:332 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:430 start_secondary+0x100/0x100 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x147