__x64_sys_mkdir+0xf3/0x140
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
------------[ cut here ]------------
percpu ref (css_release) <= 0 (-1) after switching to atomic
WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#1: kworker/u10:7/334
Modules linked in:
CPU: 1 UID: 0 PID: 334 Comm: kworker/u10:7 Tainted: G        W           6.17.0-rc3-next-20250829 #1 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Workqueue: kvfree_rcu_reclaim kfree_rcu_work
RIP: 0010:percpu_ref_switch_to_atomic_rcu+0x3cc/0x480
Code: 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 9e 00 00 00 49 8b 75 e8 48 c7 c7 80 97 e2 84 e8 75 c5 e9 fe 90 <0f> 0b 90 90 e9 2b ff ff ff e8 f6 de 5f ff e9 9e fe ff ff e8 7c df
RSP: 0018:ffff88806cf08e20 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8139de70
RDX: ffff888016399b80 RSI: ffffffff8139de7e RDI: 0000000000000001
RBP: 7fffffffffffffff R08: 0000000000000001 R09: ffffed100d9e4801
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88803c330780
R13: ffff88803c3307a0 R14: 0000000000000002 R15: 0000000000000003
FS:  0000000000000000(0000) GS:ffff8880e56dd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb3e797c700 CR3: 0000000013c15000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 rcu_core+0x7c8/0x1800
 handle_softirqs+0x1b1/0x770
 __irq_exit_rcu+0xc4/0x100
 irq_exit_rcu+0x9/0x20
 sysvec_apic_timer_interrupt+0x70/0x80
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:rcu_is_watching+0x30/0x70
Code: ff 05 a4 3d 29 06 65 48 8b 1d 94 3d 29 06 48 8d bb 50 48 85 87 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 26 8b 83 50 48 85
RSP: 0018:ffff888017b976d0 EFLAGS: 00000216
RAX: dffffc0000000000 RBX: ffff8880e56dd000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88806cf31850
RBP: ffffffff85c1c760 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000003be53 R11: 0000000000004433 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888017b977c8
 lock_acquire+0x18c/0x2f0
 unwind_next_frame+0xcd/0x2540
 arch_stack_walk+0x86/0xf0
 stack_trace_save+0x8e/0xc0
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_save_free_info+0x3a/0x60
 __kasan_slab_free+0x3f/0x50
 kmem_cache_free_bulk+0x2f8/0x610
 kvfree_rcu_bulk+0x1a3/0x250
 kfree_rcu_work+0xe8/0x160
 process_one_work+0x8e1/0x19c0
 worker_thread+0x67e/0xe90
 kthread+0x3c8/0x740
 ret_from_fork+0x34b/0x430
 ret_from_fork_asm+0x1a/0x30
 </TASK>
irq event stamp: 808588
hardirqs last  enabled at (808596): [<ffffffff81541b18>] __up_console_sem+0x78/0x80
hardirqs last disabled at (808605): [<ffffffff81541afd>] __up_console_sem+0x5d/0x80
softirqs last  enabled at (806536): [<ffffffff8488ae65>] ieee80211_ibss_work+0x2e5/0x1360
softirqs last disabled at (807623): [<ffffffff813bb364>] __irq_exit_rcu+0xc4/0x100
---[ end trace 0000000000000000 ]---
percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88803c330780 pointer offset 0 size 64
percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88801f7f6200 pointer offset 0 size 64
----------------
Code disassembly (best guess):
   0:	ff 05 a4 3d 29 06    	incl   0x6293da4(%rip)        # 0x6293daa
   6:	65 48 8b 1d 94 3d 29 	mov    %gs:0x6293d94(%rip),%rbx        # 0x6293da2
   d:	06
   e:	48 8d bb 50 48 85 87 	lea    -0x787ab7b0(%rbx),%rdi
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 fa             	mov    %rdi,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 f8             	mov    %rdi,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 26                	jne    0x61
  3b:	8b                   	.byte 0x8b
  3c:	83 50 48 85          	adcl   $0xffffff85,0x48(%rax)