rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=6544/0/0x1 softirq=61973/61974 fqs=184 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4989/1:b..l.. rcu: (detected by 0, t=10502 jiffies, g=64521, q=298 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L Y syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP, [Y]=FORCED_BIND Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 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:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_is_held_type+0x53/0x140 kernel/locking/lockdep.c:6012 Code: 56 41 55 41 54 55 53 48 83 ec 08 65 48 8b 2d 5c bf d0 09 8b 95 a4 0b 00 00 85 d2 0f 85 a7 00 00 00 48 89 fb 41 89 f4 9c 41 5d 48 c7 c7 73 84 70 8e e8 e0 1a 00 00 65 ff 05 b1 08 d1 09 8b 85 RSP: 0018:ffffc90000a08e20 EFLAGS: 00000046 RAX: 00000000ffffffff RBX: ffff8880b8128858 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8880b8128858 RBP: ffff88801fe8a580 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffff R13: 0000000000000046 R14: 0000000000000001 R15: ffff8880b8128840 FS: 0000000000000000(0000) GS:ffff8881225ba000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33ffdff8 CR3: 0000000038719000 CR4: 00000000003526f0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] enqueue_hrtimer+0x24f/0x2f0 kernel/time/hrtimer.c:1135 __run_hrtimer kernel/time/hrtimer.c:2091 [inline] __hrtimer_run_queues+0x6d3/0x9a0 kernel/time/hrtimer.c:2132 hrtimer_interrupt+0x441/0xaa0 kernel/time/hrtimer.c:2251 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 77 a8 02 e9 c3 63 03 00 0f 1f 00 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 c3 0d 26 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197e00 EFLAGS: 00000246 RAX: 0000000002778fed RBX: ffff88801fe8a580 RCX: ffffffff8be5b325 RDX: 0000000000000001 RSI: ffffffff8e613628 RDI: ffffffff8c831080 RBP: ffffed1003fd14b0 R08: 0000000000000001 R09: ffffed1017026825 R10: ffff8880b813412b R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x158 task:udevd state:R running task stack:24568 pid:4989 tgid:4989 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x125e/0x6990 kernel/sched/core.c:7382 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7662 irqentry_exit_cond_resched arch/x86/include/asm/fred.h:105 [inline] irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:453 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline] irqentry_exit+0x33f/0xab0 kernel/entry/common.c:154 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x2ec/0x2090 arch/x86/kernel/unwind_orc.c:510 Code: 4f 8d 84 00 f0 b5 02 93 49 81 f8 6a f7 cd 93 0f 87 8f 08 00 00 29 ca 48 8d 3c bd f4 34 7b 92 4c 89 f9 48 89 c6 e8 34 f5 ff ff <48> 89 c1 48 85 c9 0f 85 c5 01 00 00 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc9000463f918 EFLAGS: 00000292 RAX: ffffffff931b4260 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff928b9294 RBP: ffffc9000463f9d0 R08: ffffffff931b4266 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000017afd R12: ffffc9000463f9d8 R13: ffffc9000463f988 R14: ffffc9000463f9bd R15: ffffffff827afd86 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2780 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x127/0x6c0 mm/slub.c:6757 free_filename fs/namei.c:152 [inline] putname+0xb1/0x110 fs/namei.c:311 class_filename_destructor include/linux/fs.h:2589 [inline] class_filename_flags_destructor include/linux/fs.h:2591 [inline] do_sys_openat2+0x100/0x1d0 fs/open.c:1441 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1459 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f72750a7407 RSP: 002b:00007ffce97f2c10 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f7275750880 RCX: 00007f72750a7407 RDX: 0000000000080141 RSI: 0000558630d1f02e RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001a4 R11: 0000000000000202 R12: 00000000ffffffff R13: 00000000ffffffff R14: ffffffffffffffff R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10134 jiffies! g64521 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:28696 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x125e/0x6990 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7474 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x930 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x179/0x260 kernel/rcu/tree.c:2330 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L Y syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP, [Y]=FORCED_BIND Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 77 a8 02 e9 c3 63 03 00 0f 1f 00 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 c3 0d 26 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8fc07cf0 EFLAGS: 00000246 RAX: 000000000284744b RBX: ffffffff8fc91580 RCX: ffffffff8be5b325 RDX: 0000000000000001 RSI: ffffffff8e613628 RDI: ffffffff8c831080 RBP: fffffbfff1f922b0 R08: 0000000000000001 R09: ffffed1017006825 R10: ffff8880b803412b R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1f80fa2 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881224ba000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f34893f62f8 CR3: 0000000058d4f000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x2d3/0x2e0 init/main.c:793 start_kernel+0x48e/0x490 init/main.c:1251 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158