rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20804/1:b..l P13870/1:b..l rcu: (detected by 1, t=10502 jiffies, g=125481, q=182 ncpus=2) task:syz-executor state:R running task stack:23680 pid:13870 tgid:13870 ppid:5212 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 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_release+0x658/0xa30 kernel/locking/lockdep.c:5784 Code: 3c 3b 00 74 08 4c 89 f7 e8 05 b5 87 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc90003f9f420 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920007f3e96 RCX: ffffc90003f9f403 RDX: 0000000000000001 RSI: ffffffff8beae6e0 RDI: ffffffff8c3fb980 RBP: ffffc90003f9f548 R08: ffffffff8ff7436f R09: 1ffffffff1fee86d R10: dffffc0000000000 R11: fffffbfff1fee86e R12: 1ffff920007f3e90 R13: 0000000000000246 R14: ffffc90003f9f4b0 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:336 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] page_ext_put+0xa3/0xc0 mm/page_ext.c:550 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1102 [inline] free_unref_folios+0x1023/0x1ac0 mm/page_alloc.c:2667 folios_put_refs+0x76e/0x860 mm/swap.c:1039 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:332 __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 exit_mmap+0x44f/0xc80 mm/mmap.c:3425 __mmput+0x115/0x380 kernel/fork.c:1345 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f49f937cef9 RSP: 002b:00007ffe1c41e8c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000043 RCX: 00007f49f937cef9 RDX: 00007f49f937b9a0 RSI: 0000000000000004 RDI: 0000000000000043 RBP: 00007f49f9536a38 R08: 00007ffe1c41c666 R09: 000000000000000c R10: 000000000000001a R11: 0000000000000246 R12: 000000000000000c R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:syz.4.5037 state:R running task stack:24672 pid:20804 tgid:20804 ppid:18902 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6708 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6732 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1688 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0x3818/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3412 __mmput+0x115/0x380 kernel/fork.c:1345 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7fcf1c17cef9 RSP: 002b:00007ffd01d8b458 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf1c17cef9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd01d8b4ac R08: 00007ffd01d8b53f R09: 0000000000165198 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000032 R13: 0000000000165198 R14: 000000000016512c R15: 00007ffd01d8b500 rcu: rcu_preempt kthread starved for 10286 jiffies! g125481 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:26448 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.11.0-rc6-syzkaller-00070-gc763c4339688 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 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:92 [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 d6 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 25 2e 98 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d08 EFLAGS: 00000246 RAX: ffff88801cef0000 RBX: ffff888020abe064 RCX: 0000000002132b71 RDX: 0000000000000001 RSI: ffff888020abe000 RDI: ffff888020abe064 RBP: 000000000003a638 R08: ffff8880b8937c7b R09: 1ffff11017126f8f R10: dffffc0000000000 R11: ffffffff8bb13c50 R12: ffff888020322000 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8eed1cc0 FS: 0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1c718fb972 CR3: 000000002f2ba000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x112/0x480 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:230 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:326 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424 start_secondary+0x100/0x100 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x147