Re: [syzbot] Monthly rdma report (Nov 2024)

From: Zhu Yanjun
Date: Fri Nov 29 2024 - 06:31:01 EST


On 29.11.24 09:55, syzbot wrote:
Hello rdma maintainers/developers,

This is a 31-day syzbot report for the rdma subsystem.
All related reports/information can be found at:
https://syzkaller.appspot.com/upstream/s/rdma

During the period, 2 new issues were detected and 0 were fixed.
In total, 8 issues are still open and 61 have already been fixed.

Some of the still happening issues:

Ref Crashes Repro Title
<1> 350 No INFO: task hung in disable_device
https://syzkaller.appspot.com/bug?extid=4d0c396361b5dc5d610f
<2> 231 No INFO: task hung in rdma_dev_change_netns
https://syzkaller.appspot.com/bug?extid=73c5eab674c7e1e7012e
<3> 51 No WARNING in rxe_pool_cleanup
https://syzkaller.appspot.com/bug?extid=221e213bf17f17e0d6cd

To this rxe problem, I found the following bug reports.
"
[syzbot] Monthly rdma report (Nov 2024) 0 (1) 2024/11/29 08:55
[syzbot] Monthly rdma report (Oct 2024) 0 (1) 2024/10/28 20:45
[syzbot] Monthly rdma report (Sep 2024) 0 (1) 2024/09/27 13:28
[syzbot] Monthly rdma report (Aug 2024) 1 (2) 2024/08/31 04:02
[syzbot] [rdma?] WARNING in rxe_pool_cleanup 0 (1) 2024/05/13 02:22
"
It means that pd_pool is not empty when rxe link is removed in many testcases.

But to the pd, the caller should call the following to allocate a pd and destroy a pd.

"
.alloc_pd = rxe_alloc_pd,
...
.dealloc_pd = rxe_dealloc_pd,
"

That is, the caller should create a pd when rdma link is created. And the caller should destroy a pd when rdma link is removed.

When pd pool is not empty, it seems that at least one pd is not removed when rdma link is removed. The caller should check the application to remove this pd before a rdma link is removed.

It is the caller to create and destroy pd, not rxe.

I am not sure whether we should add logs into rxe_alloc_pd and rxe_dealloc_pd to notify the caller or not.

Zhu Yanjun

<4> 46 No INFO: task hung in add_one_compat_dev (3)
https://syzkaller.appspot.com/bug?extid=6dee15fdb0606ef7b6ba
<5> 12 Yes possible deadlock in sock_set_reuseaddr
https://syzkaller.appspot.com/bug?extid=af5682e4f50cd6bce838

---
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