rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6411/1:b..l P13126/2:b..l (detected by 1, t=10502 jiffies, g=131949, q=55 ncpus=2) task:syz-executor.1 state:R running task stack:21400 pid:13126 ppid:13118 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:433 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:seqcount_lockdep_reader_access+0x1d2/0x220 include/linux/seqlock.h:105 Code: 5e e8 22 20 8b ff 4d 85 f6 48 bb 00 00 00 00 00 fc ff df 75 07 e8 0e 20 8b ff eb 06 e8 07 20 8b ff fb 48 c7 04 24 0e 36 e0 45 <4a> c7 04 23 00 00 00 00 66 42 c7 44 23 09 00 00 42 c6 44 23 0b 00 RSP: 0018:ffffc90003dbf780 EFLAGS: 00000293 RAX: ffffffff81ff52b9 RBX: dffffc0000000000 RCX: ffff888084698000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003dbf830 R08: ffffffff81ff5294 R09: fffffbfff2092259 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920007b7ef0 R13: ffffc90003dbf7a0 R14: 0000000000000200 R15: 0000000000000046 read_seqbegin include/linux/seqlock.h:836 [inline] read_seqbegin_or_lock include/linux/seqlock.h:1140 [inline] prepend_path+0x2d6/0xbe0 fs/d_path.c:170 d_absolute_path+0x175/0x300 fs/d_path.c:233 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x2aa/0x5d0 security/tomoyo/realpath.c:271 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x29f/0x710 security/tomoyo/file.c:822 tomoyo_path_unlink+0xcc/0x100 security/tomoyo/tomoyo.c:149 security_path_unlink+0xd7/0x130 security/security.c:1189 do_unlinkat+0x3e0/0x820 fs/namei.c:4394 __do_sys_unlink fs/namei.c:4446 [inline] __se_sys_unlink fs/namei.c:4444 [inline] __x64_sys_unlink+0x45/0x50 fs/namei.c:4444 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f8ee727c557 RSP: 002b:00007ffe564a2538 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8ee727c557 RDX: 00007ffe564a2560 RSI: 00007ffe564a25f0 RDI: 00007ffe564a25f0 RBP: 00007ffe564a25f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe564a36b0 R13: 00007f8ee72c83b9 R14: 00000000001e0599 R15: 0000000000000006 task:kworker/u4:72 state:R running task stack:23032 pid:6411 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:433 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline] RIP: 0010:write_comp_data kernel/kcov.c:236 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x30/0x80 kernel/kcov.c:284 Code: 8b 0d 94 fa 77 7e 65 8b 05 95 fa 77 7e a9 00 01 ff 00 74 10 a9 00 01 00 00 74 57 83 b9 1c 16 00 00 00 74 4e 8b 81 f8 15 00 00 <83> f8 03 75 43 48 8b 91 00 16 00 00 44 8b 89 fc 15 00 00 49 c1 e1 RSP: 0018:ffffc9000d14fa58 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000055fd0 RCX: ffff888023dc5940 RDX: 0000000000000000 RSI: 0000000000055fd0 RDI: 0000000000055fd0 RBP: ffffc9000d14fb70 R08: ffffffff8908673e R09: fffffbfff2092245 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000055fd0 R14: ffffffff920e32c0 R15: ffff88814baafe80 inet_twsk_purge+0x71e/0xb60 net/ipv4/inet_timewait_sock.c:337 ops_exit_list net/core/net_namespace.c:174 [inline] cleanup_net+0x763/0xb60 net/core/net_namespace.c:601 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: rcu_preempt kthread starved for 9696 jiffies! g131949 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:25176 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x2d2/0x1120 kernel/rcu/tree.c:1674 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1873 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.74-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline] RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572 Code: bf f5 f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 c4 7a fc f6 0f 1f 44 00 00 e8 6a bb f5 f6 0f 00 2d 43 53 b2 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 1b 0e 4d f7 RSP: 0018:ffffc90000177b80 EFLAGS: 000002d3 RAX: ffffffff8a94b756 RBX: 0000000000000000 RCX: ffff88813fef9dc0 RDX: 0000000000000000 RSI: ffffffff8aebe640 RDI: ffffffff8b3cfa80 RBP: ffffc90000177c10 R08: ffffffff8a94b738 R09: ffffed1027fdf3b9 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200002ef70 R13: ffff8881456a7004 R14: ffffc90000177ba0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0750bc46c0 CR3: 000000002972d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:709 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3ce/0x680 kernel/sched/idle.c:303 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xcf/0xdb