[syzbot] [rdma?] WARNING in ib_dealloc_device

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7f87a5ea75f0 Merge tag 'hid-for-linus-2026040801' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11778eba580000
kernel config: https://syzkaller.appspot.com/x/.config?x=45cb3c58fd963c27
dashboard link: https://syzkaller.appspot.com/bug?extid=03393ff6c35fd2cc43de
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0f5deca1373e/disk-7f87a5ea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6aea6c1c6b6e/vmlinux-7f87a5ea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/61444b289e96/bzImage-7f87a5ea.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+03393f...@syzkaller.appspotmail.com

------------[ cut here ]------------
!xa_empty(&device->compat_devs)
WARNING: drivers/infiniband/core/device.c:682 at ib_dealloc_device+0x187/0x200 drivers/infiniband/core/device.c:682, CPU#0: kworker/u8:37/4856
Modules linked in:
CPU: 0 UID: 0 PID: 4856 Comm: kworker/u8:37 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: ib-unreg-wq ib_unregister_work
RIP: 0010:ib_dealloc_device+0x187/0x200 drivers/infiniband/core/device.c:682
Code: e8 de ec ad f9 48 89 df e8 56 59 07 00 48 81 c3 30 08 00 00 48 89 df 5b 41 5c 41 5e 41 5f 5d e9 0f 09 60 fd e8 ba ec ad f9 90 <0f> 0b 90 e9 72 ff ff ff e8 ac ec ad f9 90 0f 0b 90 eb 8f e8 a1 ec
RSP: 0018:ffffc9000f49fa18 EFLAGS: 00010293
RAX: ffffffff88169536 RBX: ffff888039d40000 RCX: ffff88806a691e80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888039d41308 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1ed4eb7 R12: 1ffff110073a81fd
R13: dffffc0000000000 R14: ffff888039d41268 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126332000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff6d2897e9c CR3: 0000000022382000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000f1ffffdf
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__ib_unregister_device+0x393/0x3f0 drivers/infiniband/core/device.c:1545
ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1639
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>


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