[syzbot] WARNING: refcount bug in free_netdevs

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 591cd61541b9 Add linux-next specific files for 20221207
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1773a623880000
kernel config: https://syzkaller.appspot.com/x/.config?x=8b2d3e63e054c24f
dashboard link: https://syzkaller.appspot.com/bug?extid=a1ed8ffe3121380cd5dd
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bc862c01ec56/disk-591cd615.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8f9b93f8ed2f/vmlinux-591cd615.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9d5cb636d548/bzImage-591cd615.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a1ed8f...@syzkaller.appspotmail.com

------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 1 PID: 33 at lib/refcount.c:31 refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31
Modules linked in:
CPU: 1 PID: 33 Comm: kworker/u4:2 Not tainted 6.1.0-rc8-next-20221207-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: ib-unreg-wq ib_unregister_work
RIP: 0010:refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31
Code: 05 5a 60 51 0a 01 e8 35 0a b5 05 0f 0b e9 d3 fe ff ff e8 6c 9b 75 fd 48 c7 c7 c0 6d a6 8a c6 05 37 60 51 0a 01 e8 16 0a b5 05 <0f> 0b e9 b4 fe ff ff 48 89 ef e8 5a b5 c3 fd e9 5c fe ff ff 0f 1f
RSP: 0018:ffffc90000aa7b30 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880172f9d40 RSI: ffffffff8166b1dc RDI: fffff52000154f58
RBP: ffff88807906c600 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000001 R11: 0000000000000000 R12: 1ffff92000154f6b
R13: 0000000000000000 R14: ffff88807906c600 R15: ffff888046894000
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe350a8ff8 CR3: 000000007a9e7000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__refcount_dec include/linux/refcount.h:344 [inline]
refcount_dec include/linux/refcount.h:359 [inline]
ref_tracker_free+0x539/0x6b0 lib/ref_tracker.c:118
netdev_tracker_free include/linux/netdevice.h:4039 [inline]
netdev_put include/linux/netdevice.h:4056 [inline]
dev_put include/linux/netdevice.h:4082 [inline]
free_netdevs+0x1f8/0x470 drivers/infiniband/core/device.c:2204
__ib_unregister_device+0xa0/0x1a0 drivers/infiniband/core/device.c:1478
ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1586
process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
worker_thread+0x669/0x1090 kernel/workqueue.c:2436
kthread+0x2e8/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.