rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5926/1:b..l P7434/1:b..l rcu: (detected by 0, t=10502 jiffies, g=24893, q=242 ncpus=2) task:udevd state:R running task stack:24888 pid:7434 tgid:7434 ppid:5206 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:109 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x2b4/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: 00 00 fc ff df 0f 84 03 02 00 00 4a 8d 14 ad e8 7a ae 8f 45 29 e8 4a 8d 1c 82 48 83 c3 fc 49 89 d5 48 39 da 0f 86 1c 10 00 00 <49> 29 d5 e9 80 00 00 00 31 db e9 eb 16 00 00 49 81 fc 00 a0 05 91 RSP: 0018:ffffc9000455f138 EFLAGS: 00000212 RAX: ffffffff8fd610f8 RBX: ffffffff8fd610fc RCX: ffffffff8fd61100 RDX: ffffffff8fd610fc RSI: ffffffff90627126 RDI: ffffffff8be1b9e0 RBP: ffffffff8fd61100 R08: 0000000000000001 R09: ffffffff8172aae5 R10: ffffc9000455f258 R11: ffffffff81acfd40 R12: ffffffff84776289 R13: ffffffff8fd610fc R14: ffffc9000455f208 R15: ffffffff8fd610fc arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 tomoyo_path_number_perm+0x47a/0x5a0 security/tomoyo/file.c:736 tomoyo_path_mknod+0x142/0x190 security/tomoyo/tomoyo.c:252 security_path_mknod+0x17e/0x3a0 security/security.c:1899 may_o_create fs/namei.c:3536 [inline] lookup_open fs/namei.c:3680 [inline] open_last_lookups fs/namei.c:3816 [inline] path_openat+0xd56/0x3830 fs/namei.c:4052 do_filp_open+0x1fa/0x410 fs/namei.c:4082 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc803aa7407 RSP: 002b:00007ffe2591d670 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc804171880 RCX: 00007fc803aa7407 RDX: 0000000000080241 RSI: 00007ffe2591dbd0 RDI: ffffffffffffff9c RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000202 R12: 0000560f5ffd5dfc R13: 0000560f5ffd5dfc R14: 0000000000000001 R15: 0000560f5fff0140 task:kworker/0:6 state:R running task stack:22744 pid:5926 tgid:5926 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217 Code: 24 65 48 8b 0c 25 08 90 9c 92 65 8b 15 58 6a dc 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c <8b> 91 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 RSP: 0018:ffffc90004a67918 EFLAGS: 00000246 RAX: ffffffff8997e804 RBX: ffff888023e00000 RCX: ffff888021bb3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004a67a70 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e R10: dffffc0000000000 R11: fffffbfff1f4167f R12: ffff8880b8639580 R13: ffff888033599018 R14: ffff888023f4aa38 R15: 0000000000052a8f gc_worker+0xb14/0x1380 net/netfilter/nf_conntrack_core.c:1557 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 8985 jiffies! g24893 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:27296 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 de 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 ad 21 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2 RAX: 0862c2f84b5bd000 RBX: ffffffff81976918 RCX: 0862c2f84b5bd000 RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40 RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa0b3f0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50 FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557b89f5c8 CR3: 000000005e41a000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:745 start_kernel+0x47d/0x500 init/main.c:1102 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147