From: Andrew Morton <akpm@linux-foundation.org>
To: Rafael Aquini <aquini@redhat.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, ying.huang@intel.com
Subject: Re: [PATCH] mm: swapfile: avoid split_swap_cluster() NULL pointer dereference
Date: Thu, 24 Sep 2020 19:59:14 -0700 [thread overview]
Message-ID: <20200924195914.d240877a10e22b457bd9b45d@linux-foundation.org> (raw)
In-Reply-To: <20200923134251.GN795820@optiplex-lnx>
On Wed, 23 Sep 2020 09:42:51 -0400 Rafael Aquini <aquini@redhat.com> wrote:
> On Tue, Sep 22, 2020 at 12:47:50PM -0700, Andrew Morton wrote:
> > On Tue, 22 Sep 2020 14:48:38 -0400 Rafael Aquini <aquini@redhat.com> wrote:
> >
> > > The swap area descriptor only gets struct swap_cluster_info *cluster_info
> > > allocated if the swapfile is backed by non-rotational storage.
> > > When the swap area is laid on top of ordinary disk spindles, lock_cluster()
> > > will naturally return NULL.
> > >
> > > CONFIG_THP_SWAP exposes cluster_info infrastructure to a broader number of
> > > use cases, and split_swap_cluster(), which is the counterpart of split_huge_page()
> > > for the THPs in the swapcache, misses checking the return of lock_cluster before
> > > operating on the cluster_info pointer.
> > >
> > > This patch addresses that issue by adding a proper check for the pointer
> > > not being NULL in the wrappers cluster_{is,clear}_huge(), in order to avoid
> > > crashes similar to the one below:
> > >
> > > ...
> > >
> > > Fixes: 59807685a7e77 ("mm, THP, swap: support splitting THP for THP swap out")
> > > Signed-off-by: Rafael Aquini <aquini@redhat.com>
> >
> > Did you consider cc:stable?
> >
>
> UGH! I missed adding it to my cc list. Shall I just forward it, now, or
> do you prefer a fresh repost?
I added the cc:stable to my copy.
next prev parent reply other threads:[~2020-09-25 2:59 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 18:48 [PATCH] mm: swapfile: avoid split_swap_cluster() NULL pointer dereference Rafael Aquini
2020-09-22 19:47 ` Andrew Morton
2020-09-23 13:42 ` Rafael Aquini
2020-09-25 2:59 ` Andrew Morton [this message]
2020-09-25 3:06 ` Huang, Ying
2020-09-25 3:10 ` Andrew Morton
2020-09-23 2:21 ` Huang, Ying
2020-09-23 4:34 ` Rafael Aquini
2020-09-23 5:13 ` Huang, Ying
2020-09-23 13:01 ` Rafael Aquini
2020-09-24 0:59 ` Huang, Ying
2020-09-24 2:09 ` Rafael Aquini
2020-09-24 3:51 ` Huang, Ying
2020-09-24 6:30 ` Rafael Aquini
2020-09-24 6:57 ` Huang, Ying
2020-09-24 7:45 ` Huang, Ying
2020-09-24 15:08 ` Rafael Aquini
2020-09-25 3:21 ` Huang, Ying
2020-09-26 15:16 ` Rafael Aquini
2020-09-27 5:33 ` Huang, Ying
2020-10-01 14:31 ` Rafael Aquini
2020-10-05 13:39 ` Rafael Aquini
2020-10-09 0:18 ` Huang, Ying
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200924195914.d240877a10e22b457bd9b45d@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=aquini@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ying.huang@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).