Re: [syzbot] [rdma?] WARNING in ib_dealloc_device

[Jiri Pirko]

Mon, Apr 13, 2026 at 05:43:53PM +0200, leon@xxxxxxxxxx wrote:
>On Sun, Apr 12, 2026 at 05:04:32PM -0700, syzbot wrote:
>> 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+03393ff6c35fd2cc43de@xxxxxxxxxxxxxxxxxxxxxxxxx
>> 
>> ------------[ 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
>
>I think that we have only one patch in this area https://patch.msgid.link/20260127093839.126291-1-jiri@xxxxxxxxxxx

Unable to find a link to this patch. But I don't see a scenario on which
this WARN can happen either. Very odd.


>
>Thanks
>
>
>> 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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>