Re: [PATCH] ublk_drv: fix NULL pointer dereference in ublk_ctrl_start_recovery()

[Li Nan]

在 2024/6/6 21:43, Changhui Zhong 写道:
> On Thu, Jun 6, 2024 at 4:05 PM Li Nan <linan666@xxxxxxxxxxxxxxx> wrote:
> > 在 2024/6/6 12:48, Changhui Zhong 写道:
> >
> > [...]
> >
> > > > Hi Changhui,
> > > >
> > > > The hang is actually expected because recovery fails.
> > > >
> > > > Please pull the latest ublksrv and check if the issue can still be
> > > > reproduced:
> > > >
> > > > https://github.com/ublk-org/ublksrv
> > > >
> > > > BTW, one ublksrv segfault and two test cleanup issues are fixed.
> > > >
> > > > Thanks,
> > > > Ming
> > >
> > > Hi,Ming and Nan
> > >
> > > after applying the new patch and pulling the latest ublksrv,
> > > I ran the test for 4 hours and did not observe any task hang.
> > > the test results looks good！
> > >
> > > Thanks，
> > > Changhui
> > >
> > >
> > > .
> >
> > Thanks for you test!
> >
> > However, I got a NULL pointer dereference bug with ublksrv. It is not
> > introduced by this patch. It seems io was issued after deleting disk. And
> > it can be reproduced by:
> >
> >     while true; do make test T=generic/004; done
>
> Hi,Nan
>
> I can not reproduce this issue with repo
> https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/log/?h=for-next
> ,
> which kernel repo do you using for test?
>
> Thanks,
> Changhui

I tested with the latest block code, commit
2ab79514109578fc4b6df90633d500cf281eb689, this issue also can be
reproduced.

The space of the root path has been filled up by
ublksrv(tests/tmpublk_loop_data_xxx), which may the issue be related to this?

--
Thanks,
Nan