[v6.1] kernel BUG in register_netdevice

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14155499580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=776b30276cd46661e9b1
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+776b30...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at net/core/dev.c:10148!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 5335 Comm: syz.0.202 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:register_netdevice+0x1b58/0x1b80 net/core/dev.c:10148
Code: ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c 29 fc ff ff 4c 89 f7 e8 19 8b 9c f9 e9 1c fc ff ff e8 6f 5e 4b f9 0f 0b e8 68 5e 4b f9 <0f> 0b e8 61 5e 4b f9 0f 0b e8 5a 5e 4b f9 41 bd 42 00 00 00 e9 41
RSP: 0018:ffffc90004c6f600 EFLAGS: 00010287
RAX: ffffffff8836cfb8 RBX: 1ffff9200098ded0 RCX: 0000000000080000
RDX: ffffc9000c549000 RSI: 000000000000069b RDI: 000000000000069c
RBP: ffffc90004c6f760 R08: ffffffff8dd5b907 R09: 1ffffffff1bab720
R10: dffffc0000000000 R11: fffffbfff1bab721 R12: dffffc0000000000
R13: ffffffff97033600 R14: 0000000000000003 R15: ffff888077964000
FS: 00007f108ab566c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f108ab35d58 CR3: 0000000088876000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
register_netdev+0x37/0x50 net/core/dev.c:10371
gether_register_netdev+0x81/0x150 drivers/usb/gadget/function/u_ether.c:886
ecm_bind+0x196/0x950 drivers/usb/gadget/function/f_ecm.c:712
usb_add_function+0x2d9/0x980 drivers/usb/gadget/composite.c:337
configfs_composite_bind+0xa02/0xf60 drivers/usb/gadget/configfs.c:1409
gadget_bind_driver+0x2af/0x760 drivers/usb/gadget/udc/core.c:1651
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x24a/0xb40 drivers/base/dd.c:638
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
__driver_attach+0x43d/0x6c0 drivers/base/dd.c:1220
bus_for_each_dev+0x182/0x1f0 drivers/base/bus.c:303
bus_add_driver+0x324/0x5d0 drivers/base/bus.c:620
driver_register+0x32d/0x430 drivers/base/driver.c:246
usb_gadget_register_driver_owner+0xf5/0x260 drivers/usb/gadget/udc/core.c:1730
gadget_dev_desc_UDC_store+0x1c3/0x2e0 drivers/usb/gadget/configfs.c:290
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1089b9e019
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:00007f108ab56028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1089e25fa0 RCX: 00007f1089b9e019
RDX: 000000000000000b RSI: 0000200000000b00 RDI: 0000000000000003
RBP: 00007f1089c3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1089e26038 R14: 00007f1089e25fa0 R15: 00007ffc63894e28
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:register_netdevice+0x1b58/0x1b80 net/core/dev.c:10148
Code: ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c 29 fc ff ff 4c 89 f7 e8 19 8b 9c f9 e9 1c fc ff ff e8 6f 5e 4b f9 0f 0b e8 68 5e 4b f9 <0f> 0b e8 61 5e 4b f9 0f 0b e8 5a 5e 4b f9 41 bd 42 00 00 00 e9 41
RSP: 0018:ffffc90004c6f600 EFLAGS: 00010287
RAX: ffffffff8836cfb8 RBX: 1ffff9200098ded0 RCX: 0000000000080000
RDX: ffffc9000c549000 RSI: 000000000000069b RDI: 000000000000069c
RBP: ffffc90004c6f760 R08: ffffffff8dd5b907 R09: 1ffffffff1bab720
R10: dffffc0000000000 R11: fffffbfff1bab721 R12: dffffc0000000000
R13: ffffffff97033600 R14: 0000000000000003 R15: ffff888077964000
FS: 00007f108ab566c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f108aaf2ff8 CR3: 0000000088876000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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