rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=931/1/0x4000000000000000 softirq=99448/99449 fqs=5035 
	(t=10502 jiffies g=131273 q=1549)
NMI backtrace for cpu 0
CPU: 0 PID: 32362 Comm: syz.7.7159 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/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+0x6ec/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+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 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:kmem_cache_free+0x129/0x210 mm/slub.c:3521
Code: 0f 85 f9 00 00 00 48 8d 4f 08 48 89 fe 48 83 ce 08 48 39 ce 0f 85 e7 00 00 00 48 8d 4a 08 65 48 0f c7 0f 0f 94 c0 a8 01 74 ab <49> 8b 4f 60 66 90 65 8b 05 42 94 44 7e 83 f8 08 73 3f 89 c0 48 0f
RSP: 0018:ffffc90000007980 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: aada1cfa5854e100
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a48c0
RBP: 0000000000000001 R08: ffffffff901f1197 R09: 1ffffffff203e232
R10: dffffc0000000000 R11: fffffbfff203e233 R12: ffffffff8820846f
R13: ffffea0001e41a80 R14: ffff88807906ac80 R15: ffff888144bf1140
 netlink_broadcast_filtered+0x107f/0x1170 net/netlink/af_netlink.c:1535
 netlink_broadcast net/netlink/af_netlink.c:1557 [inline]
 nlmsg_multicast include/net/netlink.h:1044 [inline]
 nlmsg_notify+0xdf/0x190 net/netlink/af_netlink.c:2562
 __neigh_notify+0x191/0x2e0 net/core/neighbour.c:3390
 neigh_update_notify net/core/neighbour.c:2531 [inline]
 neigh_timer_handler+0xb01/0xff0 net/core/neighbour.c:1106
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 3f b1 87 f7 65 8b 05 70 c7 37 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000384f5a0 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: aada1cfa5854e100
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001
RBP: ffffc9000384f630 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: dffffc0000000000
R13: 0000000000000100 R14: ffffffff8c44fda0 R15: 1ffff92000709eb4
 spin_unlock_irqrestore include/linux/spinlock.h:419 [inline]
 kernfs_path_from_node+0xb0e/0xb70 fs/kernfs/dir.c:226
 kernfs_path include/linux/kernfs.h:547 [inline]
 cgroup_path include/linux/cgroup.h:663 [inline]
 get_mm_memcg_path+0xba/0x330 mm/mmap_lock.c:82
 __mmap_lock_do_trace_start_locking+0xe2/0x2f0 mm/mmap_lock.c:95
 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline]
 mmap_read_lock include/linux/mmap_lock.h:116 [inline]
 acct_collect+0x6c7/0x710 kernel/acct.c:577
 do_exit+0x53e/0x2110 kernel/exit.c:860
 do_group_exit+0x12c/0x2f0 kernel/exit.c:1004
 get_signal+0x7eb/0x12e0 kernel/signal.c:2913
 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:157 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f3d1f09c159
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:00007f3d1d2b2028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000097 RBX: 00007f3d1f324180 RCX: 00007f3d1f09c159
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007f3d1f13306b R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3d1f324218 R14: 00007f3d1f324180 R15: 00007fffd0b8fc78
 </TASK>