rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=405/1/0x4000000000000000 softirq=28839/28844 fqs=2 
	(t=10502 jiffies g=34289 q=1307)
rcu: rcu_preempt kthread starved for 10498 jiffies! g34289 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:27536 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9348 Comm: syz.5.1183 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202
Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 30 c0 10 0c 48 89 de 5b e9 57 50 44 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d c4 26 89 7e 65 8b 15 c5 26 89 7e 81 e2 00
RSP: 0018:ffffc90000dd0498 EFLAGS: 00000093
RAX: ffffffff818123a6 RBX: 000000000000002c RCX: ffff88802a8b9dc0
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1b140de R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc90000dd0540 R15: 0000000000000001
FS:  00007ff4ac7546c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2c0402 CR3: 00000000520ef000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_trace_buf_alloc+0xa4/0x300 kernel/trace/trace_event_perf.c:419
 perf_trace_lock_acquire+0x1a0/0x3e0 include/trace/events/lock.h:13
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
 __debug_check_no_obj_freed lib/debugobjects.c:962 [inline]
 debug_check_no_obj_freed+0x136/0x530 lib/debugobjects.c:1003
 slab_free_hook mm/slub.c:1685 [inline]
 slab_free_freelist_hook+0x8b/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3520
 kfree_skb include/linux/skbuff.h:1118 [inline]
 __netif_receive_skb_core+0x3116/0x3690 net/core/dev.c:5525
 __netif_receive_skb_one_core net/core/dev.c:5549 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5665
 process_backlog+0x370/0x790 net/core/dev.c:6542
 __napi_poll+0xc0/0x430 net/core/dev.c:7101
 napi_poll net/core/dev.c:7168 [inline]
 net_rx_action+0x4d4/0xa10 net/core/dev.c:7258
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__unqueue_futex+0x0/0x160 kernel/futex/core.c:1517
Code: 0b 00 e9 80 fe ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 9e 4c 89 f7 e8 7e c4 50 00 eb 94 66 2e 0f 1f 84 00 00 00 00 00 66 90 <55> 41 57 41 56 41 55 41 54 53 48 89 fb 48 bd 00 00 00 00 00 fc ff
RSP: 0018:ffffc90002f0fb40 EFLAGS: 00000287
RAX: ffffffff816da010 RBX: ffffc90002f0fc00 RCX: 0000000000080000
RDX: ffffc900100af000 RSI: 0000000000003013 RDI: ffffc900030afb90
RBP: 0000000000000001 R08: ffff88802742bbab R09: 1ffff11004e85775
R10: dffffc0000000000 R11: ffffed1004e85776 R12: ffff88802742bba8
R13: dffffc0000000000 R14: ffffc900030afb90 R15: ffff88802742bb80
 mark_wake_futex+0xe8/0x150 kernel/futex/core.c:1543
 futex_wake+0x3c2/0x540 kernel/futex/core.c:1695
 do_futex+0xd73/0x12b0 kernel/futex/core.c:3988
 __do_sys_futex kernel/futex/core.c:4060 [inline]
 __se_sys_futex+0x389/0x420 kernel/futex/core.c:4041
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff4ae51be59
Code: 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 01 48
RSP: 002b:00007ff4ac7540e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007ff4ae795098 RCX: 00007ff4ae51be59
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007ff4ae79509c
RBP: 00007ff4ae795090 R08: 000a1e043f120db7 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff4ae795128 R14: 00007ffd152fd420 R15: 00007ffd152fd508
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 9302 Comm: syz.9.1175 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:___slab_alloc+0xcfa/0xdd0 mm/slub.c:3079
Code: 48 c7 44 24 38 00 00 00 00 9c 8f 44 24 38 f7 44 24 38 00 02 00 00 75 44 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 40 75 6a 4c 89 e8 48 83 c4 48 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc900000078f0 EFLAGS: 00000206
RAX: ba8f5d6bc2b14200 RBX: ffff8880b9043e70 RCX: ba8f5d6bc2b14200
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0
RBP: 0000000000000202 R08: ffffffff901d81c7 R09: 1ffffffff203b038
R10: dffffc0000000000 R11: fffffbfff203b039 R12: 0000000000000000
R13: ffff888051f3a000 R14: 0000000000000000 R15: ffff8880b9043e70
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 kmem_cache_alloc_node+0x1c3/0x2d0 mm/slub.c:3261
 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415
 alloc_skb include/linux/skbuff.h:1162 [inline]
 ndisc_alloc_skb+0xa6/0x420 net/ipv6/ndisc.c:422
 ndisc_send_rs+0x291/0x730 net/ipv6/ndisc.c:691
 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3956
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:stack_trace_consume_entry+0x9/0x270 kernel/stacktrace.c:83
Code: 00 00 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 78 75 09 48 8d 65 f0 5b 41 5e 5d c3 e8 71 b8 55 08 90 55 41 57 41 56 41 55 41 54 <53> 48 83 ec 18 48 ba 00 00 00 00 00 fc ff df 4c 8d 47 10 4c 89 c5
RSP: 0018:ffffc9000327f2b8 EFLAGS: 00000286
RAX: ffffffff81ed58fc RBX: ffffc9000327f3a0 RCX: 0000000080000001
RDX: ffffc9000327f301 RSI: ffffffff81ed58fc RDI: ffffc9000327f3a0
RBP: ffffc9000327f370 R08: ffffc9000327f347 R09: ffffc9000327f338
R10: dffffc0000000000 R11: fffff5200064fe69 R12: ffff888021401dc0
R13: ffff888016de9b40 R14: ffffffff8167c1b0 R15: ffffc9000327f2e8
 arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:728 [inline]
 __kernfs_new_node+0xe3/0x6c0 fs/kernfs/dir.c:593
 kernfs_new_node+0x148/0x250 fs/kernfs/dir.c:669
 __kernfs_create_file+0x47/0x2e0 fs/kernfs/file.c:985
 cgroup_add_file kernel/cgroup/cgroup.c:4091 [inline]
 cgroup_addrm_files+0xac5/0x1020 kernel/cgroup/cgroup.c:4153
 css_populate_dir+0x19b/0x2f0 kernel/cgroup/cgroup.c:1739
 cgroup_mkdir+0xca0/0xec0 kernel/cgroup/cgroup.c:5605
 kernfs_iop_mkdir+0x24c/0x3d0 fs/kernfs/dir.c:1175
 vfs_mkdir+0x387/0x570 fs/namei.c:4073
 do_mkdirat+0x1df/0x5b0 fs/namei.c:4098
 __do_sys_mkdirat fs/namei.c:4113 [inline]
 __se_sys_mkdirat fs/namei.c:4111 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc6d0e60e59
Code: 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 01 48
RSP: 002b:00007fc6cf0ba028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fc6d10d9fa0 RCX: 00007fc6d0e60e59
RDX: 00000000000001ff RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fc6d0ef6d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc6d10da038 R14: 00007fc6d10d9fa0 R15: 00007ffe3676ca38
 </TASK>