rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10520/1:b..l P9917/2:b..l rcu: (detected by 1, t=10502 jiffies, g=62781, q=601 ncpus=2) task:udevd state:R running task stack:25680 pid:9917 tgid:9917 ppid:4670 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5727 Code: c1 05 aa 11 9a 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90003e8f830 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920007d1f08 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b4cc800 RDI: ffffffff8bb08a80 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff28c5ad8 R10: ffffffff9462d6c7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb5ca0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] prepend_path+0x26d/0xf50 fs/d_path.c:168 d_absolute_path+0xff/0x1b0 fs/d_path.c:234 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x36a/0x720 security/tomoyo/realpath.c:271 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x273/0x450 security/tomoyo/file.c:822 tomoyo_path_symlink+0x98/0xe0 security/tomoyo/tomoyo.c:212 security_path_symlink+0x108/0x170 security/security.c:1876 do_symlinkat+0x10e/0x310 fs/namei.c:4592 __do_sys_symlink fs/namei.c:4615 [inline] __se_sys_symlink fs/namei.c:4613 [inline] __x64_sys_symlink+0x75/0x90 fs/namei.c:4613 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f014f517ce7 RSP: 002b:00007fff8578a408 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fff8578a4a8 RCX: 00007f014f517ce7 RDX: 000055e0fca5e23c RSI: 00007fff8578adc8 RDI: 00007fff8578a4a8 RBP: 00007fff8578adc8 R08: 0000000000000005 R09: a4952ee03b05affc R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000005 R13: 000055e5a2fe28b0 R14: 000055e5a3024760 R15: 00007fff8578add6 task:syz.3.1456 state:R running task stack:25648 pid:10520 tgid:10519 ppid:9790 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x1c90/0x23a0 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 save_stack+0x162/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x8d/0x400 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_folios+0x9e9/0x1390 mm/page_alloc.c:2660 folios_put_refs+0x560/0x760 mm/swap.c:1039 free_pages_and_swap_cache+0x36d/0x510 mm/swap_state.c:332 __tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0xe9/0x590 mm/mmu_gather.c:373 zap_pte_range mm/memory.c:1697 [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+0x1c88/0x3c10 mm/memory.c:1807 unmap_single_vma+0x194/0x2b0 mm/memory.c:1853 unmap_vmas+0x22f/0x490 mm/memory.c:1897 exit_mmap+0x1b8/0xb20 mm/mmap.c:3412 __mmput+0x12a/0x480 kernel/fork.c:1345 mmput+0x62/0x70 kernel/fork.c:1367 exit_mm kernel/exit.c:571 [inline] do_exit+0x9bf/0x2bb0 kernel/exit.c:869 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 get_signal+0x25fd/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f61885779f9 RSP: 002b:00007f6189380038 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: 00000000003ffb80 RBX: 00007f6188705f80 RCX: 00007f61885779f9 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 0000000000000060 RBP: 00007f61885e58ee R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6188705f80 R15: 00007ffd3f2aa508 rcu: rcu_preempt kthread starved for 8932 jiffies! g62781 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:27680 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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-rc2-syzkaller-00111-gee9a43b7cfe2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 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+0x1a/0x20 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 28 b7 f1 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d d8 ce a9 00 fb f4 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d58 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b1206f9 RDX: 0000000000000001 RSI: ffff88801a2e3000 RDI: ffff88801a2e3064 RBP: ffff88801a2e3064 R08: 0000000000000001 R09: ffffed1017266fd9 R10: ffff8880b9337ecb R11: 0000000000000000 R12: ffff8880183af000 R13: ffffffff8e9518c0 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f809ff8 CR3: 0000000022878000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x85/0x500 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:388 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x313/0x3f0 kernel/sched/idle.c:326 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:424 start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x148