linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Kent Overstreet <kent.overstreet@linux.dev>
To: Youling Tang <youling.tang@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-mm@kvack.org,  linux-kernel@vger.kernel.org,
	Youling Tang <tangyouling@kylinos.cn>
Subject: Re: [PATCH] mm: list_lru: Fix NULL pointer dereference in list_lru_add()
Date: Fri, 12 Jul 2024 00:07:32 -0400	[thread overview]
Message-ID: <sd32qchit33aafht27utinrz5dizw62qbtwdmwbtugqrlglmtx@6aitsotgqnpi> (raw)
In-Reply-To: <20240712032554.444823-1-youling.tang@linux.dev>

On Fri, Jul 12, 2024 at 11:25:54AM GMT, Youling Tang wrote:
> From: Youling Tang <tangyouling@kylinos.cn>
> 
> Note that list_lru_from_memcg_idx() may return NULL, so it is necessary
> to error handle the return value to avoid triggering NULL pointer
> dereference BUG.
> 
> The issue was triggered for discussion [1],
> Link [1]: https://lore.kernel.org/linux-bcachefs/84de6cb1-57bd-42f7-8029-4203820ef0b4@linux.dev/T/#m901bb26cdb1d9d4bacebf0d034f0a5a712cc93a6

I see no explanation for why this is the correct fix, and I doubt it is.
What's the real reason for the NULL lru_list_one, and why doesn't this
come up on other filesystems?


  reply	other threads:[~2024-07-12  4:07 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-12  3:25 Youling Tang
2024-07-12  4:07 ` Kent Overstreet [this message]
2024-07-12  4:28   ` Youling Tang
2024-07-12 15:49     ` Kent Overstreet
2024-07-16  2:28       ` Youling Tang
2024-07-16  2:30         ` Kent Overstreet
2024-07-15  3:27   ` Qi Zheng
2024-07-17  2:25     ` Youling Tang
2024-07-17  2:37       ` Qi Zheng

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=sd32qchit33aafht27utinrz5dizw62qbtwdmwbtugqrlglmtx@6aitsotgqnpi \
    --to=kent.overstreet@linux.dev \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=tangyouling@kylinos.cn \
    --cc=youling.tang@linux.dev \
    /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