rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5095/1:b..l rcu: (detected by 1, t=10502 jiffies, g=44561, q=376 ncpus=2) task:udevd state:R running task stack:22048 pid:5095 tgid:5095 ppid:4535 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 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:__preempt_count_add kernel/rcu/tree.c:720 [inline] RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:723 Code: 63 03 e9 2b ff ff ff e8 68 ef 00 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 38 7e 87 7e e8 9b 0d 01 0a 89 c3 83 f8 08 73 7a RSP: 0018:ffffc900036079c0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffea00013b8c00 RCX: ffff888027febc00 RDX: ffff888027febc00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff82044981 R09: 1ffffffff25ee2b0 R10: dffffc0000000000 R11: fffffbfff25ee2b1 R12: ffffea00013b8c00 R13: 0000000000000003 R14: ffffffff82044950 R15: ffffea00013b8c08 rcu_read_lock include/linux/rcupdate.h:782 [inline] page_ext_get+0x5a/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_page+0xd2d/0xea0 mm/page_alloc.c:2588 discard_slab mm/slub.c:2527 [inline] __put_partials+0xeb/0x130 mm/slub.c:2995 put_cpu_partial+0x17c/0x250 mm/slub.c:3070 __slab_free+0x2ea/0x3d0 mm/slub.c:4308 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3940 [inline] slab_alloc_node mm/slub.c:4002 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4009 getname_flags+0xbd/0x4f0 fs/namei.c:139 vfs_fstatat+0x11c/0x190 fs/stat.c:303 __do_sys_newfstatat fs/stat.c:468 [inline] __se_sys_newfstatat fs/stat.c:462 [inline] __x64_sys_newfstatat+0x125/0x1b0 fs/stat.c:462 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: 0033:0x7fa2867165f4 RSP: 002b:00007ffdc06a1288 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000000000000000e RCX: 00007fa2867165f4 RDX: 00007ffdc06a1298 RSI: 00007ffdc06a1367 RDI: 00000000ffffff9c RBP: 00007ffdc06a23a0 R08: 0000000000000000 R09: 00007ffdc06a2158 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc06a27c8 R13: 0000000000000000 R14: 00007ffdc06a27c8 R15: 0000556dcaeb8910 rcu: rcu_preempt kthread starved for 10457 jiffies! g44561 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:26008 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 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+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 PID: 0 Comm: swapper/1 Not tainted 6.10.0-rc5-syzkaller-00175-g6d6444ba8205 #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:113 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 80 d4 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 95 28 ab 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: ffff888017e98000 RBX: ffff88801b684064 RCX: 000000000076b449 RDX: 0000000000000001 RSI: ffff88801b684000 RDI: ffff88801b684064 RBP: 000000000003a538 R08: ffff8880b9537ccb R09: 1ffff110172a6f99 R10: dffffc0000000000 R11: ffffffff8b7d78e0 R12: ffff888019b4e800 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8eabb9a0 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f01024ecf5e CR3: 000000000e132000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:707 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: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