On 5/11/22 2:02 AM, Song Liu wrote:
> On Tue, May 10, 2022 at 5:35 AM Donald Buczek <buczek@molgen.mpg.de> wrote:
>> On 5/10/22 2:09 PM, Guoqing Jiang wrote:
>>>
>>> On 5/10/22 8:01 PM, Donald Buczek wrote:
>>>>> I guess v2 is the best at the moment. I pushed a slightly modified v2 to
>>>>> md-next.
>>>> I think, this can be used to get a double-free from md_unregister_thread.
>>>>
>>>> Please review
>>>>
>>>> https://lore.kernel.org/linux-raid/8312a154-14fb-6f07-0cf1-8c970187cc49@molgen.mpg.de/
>>> That is supposed to be addressed by the second one, pls consider it too.
>> Right, but this has not been pulled into md-next. I just wanted to note, that the current state of md-next has this problem.

Thanks for reminder.

>> If the other patch is taken, too, and works as intended, that would be solved.
>>
>>> [PATCH 2/2] md: protect md_unregister_thread from reentrancy
> Good catch!
>
> Guoqing, current 2/2 doesn't apply cleanly. Could you please resend it on top of
> md-next?

Hmm, no issue from my side.

~/source/md> git am 
0001-md-protect-md_unregister_thread-from-reentrancy.patch
Applying: md: protect md_unregister_thread from reentrancy

~/source/md> git log --oneline |head -5
dc7147a88766 md: protect md_unregister_thread from reentrancy
5a36c493dc82 md: don't unregister sync_thread with reconfig_mutex held
49c3b9266a71 block: null_blk: Improve device creation with configfs
db060f54e0c5 block: null_blk: Cleanup messages
b3a0a73e8a79 block: null_blk: Cleanup device creation and deletion

Anyway, it is attached. I will rebase it to your latest tree if 
something gets wrong.

Thanks,
Guoqing