------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: lib/refcount.c:31 at refcount_warn_saturate+0x70/0x110 lib/refcount.c:31, CPU#1: syz.0.17/5877
Modules linked in:
CPU: 1 UID: 0 PID: 5877 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:refcount_warn_saturate+0x70/0x110 lib/refcount.c:31
Code: c6 c0 fe 36 8f e8 90 e5 ee fc 83 fb 01 7e 22 83 fb 02 74 39 83 fb 03 74 47 83 fb 04 75 68 e8 f7 df ee fc 48 8d 3d b0 16 8b 0b <67> 48 0f b9 3a eb 66 85 db 74 3e 83 fb 01 75 4c e8 db df ee fc 48
RSP: 0018:ffffc900037a78c8 EFLAGS: 00010293
RAX: ffffffff84d8a429 RBX: 0000000000000004 RCX: ffff8880309bddc0
RDX: 0000000000000000 RSI: ffffffff8f36fec0 RDI: ffffffff9063bae0
RBP: ffffc900037a7a10 R08: ffff8880309bddc0 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000000 R12: ffff888077916700
R13: dffffc0000000000 R14: ffff888077916744 R15: 0000000000000001
FS:  0000555560ca5500(0000) GS:ffff888125012000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002020 CR3: 0000000074b88000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __refcount_dec include/linux/refcount.h:461 [inline]
 refcount_dec include/linux/refcount.h:476 [inline]
 ref_tracker_free+0x706/0x830 lib/ref_tracker.c:303
 netdev_tracker_free include/linux/netdevice.h:4545 [inline]
 netdev_put include/linux/netdevice.h:4562 [inline]
 io_close_queue io_uring/zcrx.c:582 [inline]
 zcrx_unregister_user+0x2d8/0x430 io_uring/zcrx.c:681
 zcrx_unregister io_uring/zcrx.c:688 [inline]
 io_register_zcrx+0x875/0xc00 io_uring/zcrx.c:1021
 __io_uring_register io_uring/register.c:942 [inline]
 __do_sys_io_uring_register io_uring/register.c:1040 [inline]
 __se_sys_io_uring_register+0xc23/0x1ab0 io_uring/register.c:1017
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0ac339e0d9
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:00007ffdd27167e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 00007f0ac3625fa0 RCX: 00007f0ac339e0d9
RDX: 0000200000000100 RSI: 0000000000000020 RDI: 0000000000000003
RBP: 00007f0ac3435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0ac3625fac R14: 00007f0ac3625fa0 R15: 00007f0ac3625fa0
 </TASK>
----------------
Code disassembly (best guess), 5 bytes skipped:
   0:	e8 90 e5 ee fc       	call   0xfceee595
   5:	83 fb 01             	cmp    $0x1,%ebx
   8:	7e 22                	jle    0x2c
   a:	83 fb 02             	cmp    $0x2,%ebx
   d:	74 39                	je     0x48
   f:	83 fb 03             	cmp    $0x3,%ebx
  12:	74 47                	je     0x5b
  14:	83 fb 04             	cmp    $0x4,%ebx
  17:	75 68                	jne    0x81
  19:	e8 f7 df ee fc       	call   0xfceee015
  1e:	48 8d 3d b0 16 8b 0b 	lea    0xb8b16b0(%rip),%rdi        # 0xb8b16d5
* 25:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2a:	eb 66                	jmp    0x92
  2c:	85 db                	test   %ebx,%ebx
  2e:	74 3e                	je     0x6e
  30:	83 fb 01             	cmp    $0x1,%ebx
  33:	75 4c                	jne    0x81
  35:	e8 db df ee fc       	call   0xfceee015
  3a:	48                   	rex.W