------------[ cut here ]------------
WARNING: CPU: 0 PID: 8423 at net/core/dev.c:9600 dev_index_reserve+0x1a2/0x1c0 net/core/dev.c:9600
Modules linked in:
CPU: 0 PID: 8423 Comm: syz-executor.2 Not tainted 6.6.0-rc6-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:dev_index_reserve+0x1a2/0x1c0 net/core/dev.c:9600
Code: 00 31 d2 4d 8d 45 50 b9 ff ff ff 7f 48 8d 74 24 20 e8 22 48 03 02 4c 89 e7 89 c3 e8 78 52 12 02 e9 48 ff ff ff e8 9e 68 56 f9 <0f> 0b bb ea ff ff ff e9 52 ff ff ff e8 6d 9a 0e 02 66 66 2e 0f 1f
RSP: 0018:ffffc90006ef7c00 EFLAGS: 00010283
RAX: 00000000000032ce RBX: 00000000db19bdeb RCX: ffffc90007721000
RDX: 0000000000040000 RSI: ffffffff883161a2 RDI: 0000000000000005
RBP: 1ffff92000ddef80 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000db19bdeb R11: ffffffff81dd0bf6 R12: ffff88801df2c010
R13: ffff88805d851d40 R14: ffff88801df2c000 R15: ffff88801df2c0f8
FS:  0000000000000000(0000) GS:ffff88802c600000(0063) knlGS:00000000f7fd3b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000030222000 CR3: 000000001dbb0000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 register_netdevice+0x69a/0x1490 net/core/dev.c:10088
 tun_set_iff drivers/net/tun.c:2850 [inline]
 __tun_chr_ioctl+0x3091/0x4700 drivers/net/tun.c:3118
 __do_compat_sys_ioctl+0x2bf/0x330 fs/ioctl.c:972
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x70/0x82
RIP: 0023:0xf7fd8579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f7fd35ac EFLAGS: 00000292 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000400454ca
RDX: 0000000020000200 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi