rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6392/1:b..l P4534/1:b..l rcu: (detected by 0, t=10502 jiffies, g=43449, q=226 ncpus=2) task:udevd state:R running task stack:25152 pid:4534 tgid:4534 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6924 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] __d_lookup+0x246/0x4c0 fs/dcache.c:2323 lookup_fast+0x17b/0x540 fs/namei.c:1650 walk_component+0x5b/0x5b0 fs/namei.c:2000 link_path_walk.part.0.constprop.0+0x77f/0xcd0 fs/namei.c:2331 link_path_walk fs/namei.c:2255 [inline] path_lookupat+0x93/0x770 fs/namei.c:2492 filename_lookup+0x1e5/0x5b0 fs/namei.c:2522 vfs_statx+0x13e/0x550 fs/stat.c:244 vfs_fstatat+0xb3/0x150 fs/stat.c:304 __do_sys_newfstatat+0xa6/0x130 fs/stat.c:468 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: 0033:0x7f767ff165f4 RSP: 002b:00007ffe66404f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000055bbeb2de2c0 RCX: 00007f767ff165f4 RDX: 00007ffe66404f88 RSI: 00007ffe66405418 RDI: 00000000ffffff9c RBP: 00007ffe66405018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe66405418 R13: 00007ffe66404f88 R14: 000055bbeb2a22c0 R15: 0000000000000000 task:kworker/u8:10 state:R running task stack:24304 pid:6392 tgid:6392 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7067 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:get_stack_info+0x63/0x150 arch/x86/kernel/dumpstack_64.c:207 Code: 5d 00 4c 89 e7 4c 89 ea 48 89 de e8 27 92 b6 09 31 ff 41 89 c4 89 c6 e8 2b 4c 5d 00 45 84 e4 0f 84 cd 00 00 00 e8 7d 51 5d 00 <48> 85 ed 74 52 e8 73 51 5d 00 45 8b 75 00 bf 3f 00 00 00 44 89 f6 RSP: 0018:ffffc90003367268 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff88807e635a00 RCX: ffffffff81309305 RDX: ffff88807e635a00 RSI: ffffffff81309313 RDI: 0000000000000001 RBP: ffffc90003367320 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000005 R12: 0000000000000001 R13: ffffc90003367300 R14: ffffc90003367328 R15: ffffc90003367320 __unwind_start+0x49c/0x880 arch/x86/kernel/unwind_orc.c:729 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xb2/0x170 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:541 kvfree_call_rcu+0x74/0xbe0 kernel/rcu/tree.c:3781 sctp_inet6addr_event+0x429/0x900 net/sctp/ipv6.c:115 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 atomic_notifier_call_chain+0x71/0x1c0 kernel/notifier.c:231 addrconf_ifdown.isra.0+0xf03/0x1b40 net/ipv6/addrconf.c:3980 addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline] call_netdevice_notifiers net/core/dev.c:2044 [inline] dev_close_many+0x333/0x6a0 net/core/dev.c:1585 unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11194 cleanup_net+0x58c/0xbf0 net/core/net_namespace.c:635 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3248 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x6c8/0xf30 kernel/workqueue.c:3409 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: rcu_preempt kthread starved for 10244 jiffies! g43449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28464 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2000 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2202 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: 0 PID: 0 Comm: swapper/0 Not tainted 6.10.0-rc6-syzkaller-00163-g661e504db04c #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+0x1a/0x20 drivers/acpi/processor_idle.c:113 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 68 54 1c 75 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 38 af b3 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:ffffffff8d807d70 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8ae767b9 RDX: 0000000000000001 RSI: ffff88801a2b9800 RDI: ffff88801a2b9864 RBP: ffff88801a2b9864 R08: 0000000000000001 R09: ffffed1017246fdd R10: ffff8880b9237eeb R11: 0000000000000000 R12: ffff88801af54000 R13: ffffffff8e742280 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020048000 CR3: 00000000660a0000 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:707 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:236 [inline] do_idle+0x313/0x3f0 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:747 start_kernel+0x3df/0x4c0 init/main.c:1103 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148