EXT4-fs (loop9): initial error at time 1776234214: ext4_orphan_get:1423 EXT4-fs (loop9): last error at time 1776234214: ext4_orphan_get:1423 rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5191/1:b..l rcu: (detected by 0, t=10503 jiffies, g=62825, q=918 ncpus=2) task:udevd state:R running task stack:22360 pid:5191 tgid:5191 ppid:1 task_flags:0x400140 flags:0x00080800 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7507 irqentry_exit+0x5e4/0x700 kernel/entry/common.c:240 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline] RIP: 0010:lock_acquire+0x8b/0x350 kernel/locking/lockdep.c:5844 Code: 0f 84 ca 01 00 00 83 3d 52 af 70 0e 00 0f 84 d3 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 bc ec 8d 00 83 3d 35 af 70 0e 00 <0f> 84 ce 00 00 00 65 8b 05 48 30 7b 11 85 c0 0f 85 bf 00 00 00 65 RSP: 0018:ffffc90003b17710 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff826f0368 RDI: 1ffffffff1ceba04 RBP: ffffffff826f034c R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff826f16e0 R12: 0000000000000002 R13: ffffffff8e75d020 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:847 [inline] class_rcu_constructor include/linux/rcupdate.h:1190 [inline] kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:74 kernfs_iop_permission+0x6c/0x430 fs/kernfs/inode.c:286 do_inode_permission fs/namei.c:578 [inline] inode_permission+0x46f/0x5f0 fs/namei.c:648 lookup_inode_permission_may_exec fs/namei.c:-1 [inline] may_lookup fs/namei.c:1972 [inline] link_path_walk+0x1149/0x18d0 fs/namei.c:2600 path_openat+0x2c3/0x3860 fs/namei.c:4854 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6410ca7407 RSP: 002b:00007ffe2c216e40 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f641146d880 RCX: 00007f6410ca7407 RDX: 0000000000080000 RSI: 00007ffe2c216fc0 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000056076d3517f5 R13: 000056076d3517f5 R14: 0000000000000001 R15: 00007ffe2c21b630 rcu: rcu_preempt kthread starved for 10493 jiffies! g62825 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11570 Comm: syz.7.1599 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_release+0x25e/0x3c0 kernel/locking/lockdep.c:5891 Code: 89 c5 7f d0 4c 89 ff 4c 89 f6 48 8b 54 24 18 e8 28 2f 00 00 48 8b 5c 24 08 48 c7 c7 a4 f2 16 8e e8 67 88 0b 0a b8 ff ff ff ff <65> 0f c1 05 9a fd 7a 11 83 f8 01 75 2e 9c 58 a9 00 02 00 00 75 42 RSP: 0018:ffffc90002f67a20 EFLAGS: 00000006 RAX: 00000000ffffffff RBX: 0000000000000006 RCX: 0000000080000003 RDX: 0000000000000002 RSI: ffffffff8e16f2a4 RDI: ffffffff8c27e080 RBP: ffff888054afc960 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520005ecf40 R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff9a53dbc8 R15: ffff888054afbd80 FS: 00007fd3334156c0(0000) GS:ffff88812555a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000200 CR3: 000000007c9d9000 CR4: 0000000000350ef0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:198 debug_object_activate+0x320/0x580 lib/debugobjects.c:853 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] remove_and_enqueue_same_base kernel/time/hrtimer.c:1259 [inline] __hrtimer_start_range_ns kernel/time/hrtimer.c:1396 [inline] hrtimer_start_range_ns+0x579/0xed0 kernel/time/hrtimer.c:1491 __posixtimer_deliver_signal kernel/time/posix-timers.c:314 [inline] posixtimer_deliver_signal+0x1ce/0x3f0 kernel/time/posix-timers.c:340 dequeue_signal+0x249/0x370 kernel/signal.c:660 get_signal+0x55d/0x1330 kernel/signal.c:2918 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd33259c817 Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 RSP: 002b:00007fd3334150e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fd332815fa8 RCX: 00007fd33259c819 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd332815fa8 RBP: 00007fd332815fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd332816038 R14: 00007ffcd1aac800 R15: 00007ffcd1aac8e8