rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5197/1:b..l rcu: (detected by 1, t=10502 jiffies, g=67953, q=417 ncpus=2) task:udevd state:R running task stack:22712 pid:5197 tgid:5197 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline] RIP: 0010:is_bpf_text_address+0x1f5/0x2b0 kernel/bpf/core.c:746 Code: ff 31 db eb 09 e8 8b c1 f0 ff 4c 8b 24 24 8b 05 11 25 f0 0b 44 39 e0 74 0a e8 77 c1 f0 ff e9 e1 fe ff ff e8 bd 58 8a 09 89 c5 <31> ff 89 c6 e8 a2 c5 f0 ff 85 ed 74 10 e8 99 aa d6 ff 84 c0 74 0e RSP: 0018:ffffc90003e778b0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff88807e571e80 RDX: 0000000000000000 RSI: 00007fb9ea515a67 RDI: ffffffffa00051c0 RBP: 0000000000000001 R08: ffffffff81d0ed76 R09: ffffffff8df419e0 R10: dffffc0000000000 R11: ffffffff81ad9fb0 R12: 00000000000007ba R13: dffffc0000000000 R14: 00007fb9ea515a67 R15: 0000000000000000 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x1c0/0x660 mm/slub.c:6876 seq_release+0x54/0x70 fs/seq_file.c:355 kernfs_fop_release+0x133/0x190 fs/kernfs/file.c:784 __fput+0x44c/0xa70 fs/file_table.c:468 fput_close_sync+0x113/0x220 fs/file_table.c:573 __do_sys_close fs/open.c:1573 [inline] __se_sys_close fs/open.c:1558 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1558 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb9ea515a67 RSP: 002b:00007ffc6dd02cd8 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000564ab476f7a0 RCX: 00007fb9ea515a67 RDX: 00007fb9ea5efea0 RSI: 0000564ab4788650 RDI: 000000000000000c RBP: 00007fb9ea5efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544 rcu: rcu_preempt kthread starved for 10535 jiffies! g67953 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:27136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: be 03 b5 f5 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 f3 10 0d 00 f3 0f 1e fa fb f4 93 03 b5 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: 35de0cdbc791c900 RBX: ffffffff81978eba RCX: 35de0cdbc791c900 RDX: 0000000000000001 RSI: ffffffff8d790209 RDI: ffffffff8bc07b60 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f81fa70 R13: 1ffff110038d6b70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125f3a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c38f7d5 CR3: 0000000034ec3000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147