[syzbot] [net?] WARNING in ipv6_add_dev

[syzbot <syzbot+3ab016dc5f28b32452c1@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    0af2f6be1b42 Linux 6.15-rc1
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=166dffb0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=66996a2350ef05e0
dashboard link: https://syzkaller.appspot.com/bug?extid=3ab016dc5f28b32452c1
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2bd38b4e51ec/disk-0af2f6be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/928b4d433463/vmlinux-0af2f6be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9c0fa5febc31/bzImage-0af2f6be.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3ab016dc5f28b32452c1@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 813 at ./include/net/netdev_lock.h:54 netdev_ops_assert_locked include/net/netdev_lock.h:54 [inline]
WARNING: CPU: 1 PID: 813 at ./include/net/netdev_lock.h:54 ipv6_add_dev+0x104c/0x1430 net/ipv6/addrconf.c:381
Modules linked in:
CPU: 1 UID: 0 PID: 813 Comm: kworker/u8:1 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound linkwatch_event
RIP: 0010:netdev_ops_assert_locked include/net/netdev_lock.h:54 [inline]
RIP: 0010:ipv6_add_dev+0x104c/0x1430 net/ipv6/addrconf.c:381
Code: ff ff e8 67 5d fe f6 48 bd 00 00 00 00 00 fc ff df 48 8b 3c 24 4c 8b 6c 24 18 4c 8b 64 24 28 e9 7f fc ff ff e8 45 5d fe f6 90 <0f> 0b 90 e9 64 f1 ff ff e8 37 5d fe f6 c6 05 16 e3 84 05 01 90 48
RSP: 0018:ffffc9001cbbf3d8 EFLAGS: 00010293
RAX: ffffffff8ac4f7db RBX: 0000000000000000 RCX: ffff88807a275a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8ac4e8fb R09: 1ffffffff201fa64
R10: dffffc0000000000 R11: fffffbfff201fa65 R12: ffff88805d942000
R13: ffff88805d942000 R14: dffffc0000000000 R15: ffff88805d942000
FS:  0000000000000000(0000) GS:ffff888125096000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f5045ffc CR3: 0000000032240000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ipv6_find_idev+0xc2/0x1e0 net/ipv6/addrconf.c:496
 addrconf_add_dev+0xbe/0x530 net/ipv6/addrconf.c:2560
 addrconf_dev_config net/ipv6/addrconf.c:3479 [inline]
 addrconf_init_auto_addrs+0x8f1/0xfe0 net/ipv6/addrconf.c:3567
 addrconf_notify+0xaff/0x1020 net/ipv6/addrconf.c:3740
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 netdev_state_change+0x123/0x1a0 net/core/dev.c:1536
 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:186
 __linkwatch_run_queue+0x451/0x6c0 net/core/link_watch.c:243
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:286
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>


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