Re: [PATCH 1/3] md/raid10: fix null-ptr-deref of mreplace in raid10_sync_request

[Li Nan]

在 2023/5/22 21:01, Yu Kuai 写道:
> Hi,
>
> 在 2023/05/22 19:54, linan666@xxxxxxxxxxxxxxx 写道:
> > From: Li Nan <linan122@xxxxxxxxxx>
> >
> > need_replace will be set to 1 if no-Faulty mreplace exists, and mreplace
> > will be deref later. However, the latter check of mreplace might set
> > mreplace to NULL, null-ptr-deref occurs if need_replace is 1 at this 
> > time.
> >
> > Fix it by merging two checks into one. And replace 'need_replace' with
> > 'mreplace' because their values are always the same.
> >
> > Fixes: ee37d7314a32 ("md/raid10: Fix raid10 replace hang when new 
> > added disk faulty")
> > Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
> > ---
> >   drivers/md/raid10.c | 13 +++++--------
> >   1 file changed, 5 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> > index 4fcfcb350d2b..e21502c03b45 100644
> > --- a/drivers/md/raid10.c
> > +++ b/drivers/md/raid10.c
> > @@ -3438,7 +3438,6 @@ static sector_t raid10_sync_request(struct mddev 
> > *mddev, sector_t sector_nr,
> >               int must_sync;
> >               int any_working;
> >               int need_recover = 0;
>
> need_recover can be removed as well. Otherwise, this patch looks good to
> me.

I agree. Let me improve this in v2.
--
Thanks,
Nan