------------[ cut here ]------------
percpu ref (io_ring_ctx_ref_free) <= 0 (-4294967295) after switching to atomic
WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#1: modprobe/9806
Modules linked in:
CPU: 1 UID: 0 PID: 9806 Comm: modprobe 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
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: ffff88801a76d280 RSI: ffffffff8139de7e RDI: 0000000000000001
RBP: 7fffffff00000000 R08: 0000000000000001 R09: ffffed100d9e4801
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800d1d2180
R13: ffff88800d1d21a0 R14: 0000000000000002 R15: 0000000000000003
FS:  0000000000000000(0000) GS:ffff8880e56dd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005591099cf080 CR3: 000000000e334000 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:kfree+0x9d/0x550
Code: d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 6d 33 dc 03 48 8b 50 08 49 89 c7 f6 c2 01 0f 85 0c 03 00 00 0f 1f 44 00 00 41 80 7f 33 f5 <0f> 85 05 03 00 00 48 8b 45 08 4d 8b 67 08 4c 89 74 24 20 48 89 44
RSP: 0018:ffff88803eb6fe50 EFLAGS: 00000246
RAX: ffffea0000833a80 RBX: ffff888020cea85c RCX: ffffffff81b5d22a
RDX: ffffea0000833a01 RSI: ffffffff81b78e1f RDI: ffff88806cf31850
RBP: ffff88803eb6feb0 R08: 0000000000000001 R09: ffffed1002c4ba5c
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffff88801e248000 R14: ffff888020cea800 R15: ffffea0000833a00
 kernel_execve+0x30f/0x3d0
 call_usermodehelper_exec_async+0x25f/0x4e0
 ret_from_fork+0x34b/0x430
 ret_from_fork_asm+0x1a/0x30
 </TASK>
irq event stamp: 1154
hardirqs last  enabled at (1162): [<ffffffff81541b18>] __up_console_sem+0x78/0x80
hardirqs last disabled at (1171): [<ffffffff81541afd>] __up_console_sem+0x5d/0x80
softirqs last  enabled at (362): [<ffffffff813bafcc>] handle_softirqs+0x50c/0x770
softirqs last disabled at (649): [<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 ffff88800d1d2180 pointer offset 0 size 64
kmemleak: Found object by alias at 0x607f1a638c3c
CPU: 0 UID: 0 PID: 9848 Comm: syz-executor.4 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
Call Trace:
 <TASK>
 dump_stack_lvl+0xca/0x120
 __lookup_object+0x94/0xb0
 delete_object_full+0x27/0x70
 free_percpu+0x30/0x1160
 futex_hash_free+0x38/0xc0
 mmput+0x2d3/0x390
 do_exit+0x79d/0x2970
 do_group_exit+0xd3/0x2a0
 get_signal+0x2315/0x2340
 arch_do_signal_or_restart+0x80/0x790
 exit_to_user_mode_loop+0x8b/0x110
 do_syscall_64+0x2f7/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb91323fb19
Code: Unable to access opcode bytes at 0x7fb91323faef.
RSP: 002b:00007fb9107b5218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fb913352f68 RCX: 00007fb91323fb19
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fb913352f6c
RBP: 00007fb913352f60 R08: 000000000000000e R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fb913352f6c
R13: 00007ffebc7b94bf R14: 00007fb9107b5300 R15: 0000000000022000
 </TASK>
kmemleak: Object (percpu) 0x607f1a638c38 (size 8):
kmemleak:   comm "syz-executor.0", pid 9861, jiffies 4295735910
kmemleak:   min_count = 1
kmemleak:   count = 0
kmemleak:   flags = 0x21
kmemleak:   checksum = 0
kmemleak:   backtrace:
 pcpu_alloc_noprof+0x87a/0x1170
 percpu_ref_init+0x37/0x400
 io_uring_setup+0x44c/0x2000
 __x64_sys_io_uring_setup+0xc8/0x170
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	48 c1 e8 0c          	shr    $0xc,%rax
   4:	48 c1 e0 06          	shl    $0x6,%rax
   8:	48 03 05 6d 33 dc 03 	add    0x3dc336d(%rip),%rax        # 0x3dc337c
   f:	48 8b 50 08          	mov    0x8(%rax),%rdx
  13:	49 89 c7             	mov    %rax,%r15
  16:	f6 c2 01             	test   $0x1,%dl
  19:	0f 85 0c 03 00 00    	jne    0x32b
  1f:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  24:	41 80 7f 33 f5       	cmpb   $0xf5,0x33(%r15)
* 29:	0f 85 05 03 00 00    	jne    0x334 <-- trapping instruction
  2f:	48 8b 45 08          	mov    0x8(%rbp),%rax
  33:	4d 8b 67 08          	mov    0x8(%r15),%r12
  37:	4c 89 74 24 20       	mov    %r14,0x20(%rsp)
  3c:	48                   	rex.W
  3d:	89                   	.byte 0x89
  3e:	44                   	rex.R