Re: [syzbot] [net?] WARNING in __linkwatch_sync_dev

[syzbot <syzbot+48c14f61594bdfadb086@syzkaller.appspotmail.com>]

syzbot has found a reproducer for the following issue on:

HEAD commit:    7702d0130dc0 Add linux-next specific files for 20250408
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=138fa7e4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=91edf513888f57d7
dashboard link: https://syzkaller.appspot.com/bug?extid=48c14f61594bdfadb086
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11520398580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16b1323f980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0603dd3556b9/disk-7702d013.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d384baaee881/vmlinux-7702d013.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1ac172735b6c/bzImage-7702d013.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+48c14f61594bdfadb086@syzkaller.appspotmail.com

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RTNL: assertion failed at ./include/net/netdev_lock.h (56)
WARNING: CPU: 1 PID: 12 at ./include/net/netdev_lock.h:56 netdev_ops_assert_locked include/net/netdev_lock.h:56 [inline]
WARNING: CPU: 1 PID: 12 at ./include/net/netdev_lock.h:56 __linkwatch_sync_dev+0x30d/0x360 net/core/link_watch.c:279
Modules linked in:
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.15.0-rc1-next-20250408-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: bond0 bond_mii_monitor
RIP: 0010:netdev_ops_assert_locked include/net/netdev_lock.h:56 [inline]
RIP: 0010:__linkwatch_sync_dev+0x30d/0x360 net/core/link_watch.c:279
Code: 7c fe ff ff e8 f4 63 cc f7 c6 05 83 28 53 06 01 90 48 c7 c7 60 5c 51 8d 48 c7 c6 8a 9b 67 8e ba 38 00 00 00 e8 04 6b 8b f7 90 <0f> 0b 90 90 e9 4d fe ff ff 89 d9 80 e1 07 38 c1 0f 8c 19 fd ff ff
RSP: 0018:ffffc90000117710 EFLAGS: 00010246
RAX: 6875daac7c816500 RBX: 0000000000000000 RCX: ffff88801c685a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81824ed2 R09: fffffbfff1d7a700
R10: dffffc0000000000 R11: fffffbfff1d7a700 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888034096008 R15: ffff888034096000
FS:  0000000000000000(0000) GS:ffff888125089000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa9d1a29440 CR3: 0000000075fc0000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ethtool_op_get_link+0x15/0x60 net/ethtool/ioctl.c:63
 bond_check_dev_link+0x1fb/0x4b0 drivers/net/bonding/bond_main.c:864
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2734 [inline]
 bond_mii_monitor+0x49d/0x3170 drivers/net/bonding/bond_main.c:2956
 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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