From: Al Viro <viro@zeniv.linux.org.uk>
To: Christian Brauner <brauner@kernel.org>
Cc: Dmitry Antipov <dmantipov@yandex.ru>,
Catalin Marinas <catalin.marinas@arm.com>,
Joel Fernandes <joel@joelfernandes.org>,
linux-fsdevel@vger.kernel.org, lvc-project@linuxtesting.org
Subject: Re: [PATCH] [RFC] fs: prefer kfree_rcu() in fasync_remove_entry()
Date: Fri, 9 Feb 2024 16:36:46 +0000 [thread overview]
Message-ID: <20240209163646.GD608142@ZenIV> (raw)
In-Reply-To: <20240209-hierzu-getrunken-0b1a3bfc7d16@brauner>
On Fri, Feb 09, 2024 at 03:22:15PM +0100, Christian Brauner wrote:
> On Fri, Feb 09, 2024 at 03:52:19PM +0300, Dmitry Antipov wrote:
> > In 'fasync_remove_entry()', prefer 'kfree_rcu()' over 'call_rcu()' with dummy
> > 'fasync_free_rcu()' callback. This is mostly intended in attempt to fix weird
> > https://syzkaller.appspot.com/bug?id=6a64ad907e361e49e92d1c4c114128a1bda2ed7f,
> > where kmemleak may consider 'fa' as unreferenced during RCU grace period. See
> > https://lore.kernel.org/stable/20230930174657.800551-1-joel@joelfernandes.org
> > as well. Comments are highly appreciated.
> >
> > Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
> > ---
>
> Yeah, according to commit ae65a5211d90 ("mm/slab: document kfree() as
> allowed for kmem_cache_alloc() objects") this is now guaranteed to work
> for kmem_cache_alloc() objects since slab is gone. So independent of
> syzbot this seems like a decent enough cleanup.
Sure, but we'd better make very sure that it does *NOT* get picked by any
-stable prior to 6.4.
next prev parent reply other threads:[~2024-02-09 16:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-09 12:52 [PATCH] [RFC] fs: prefer kfree_rcu() in fasync_remove_entry() Dmitry Antipov
2024-02-09 14:21 ` Christian Brauner
2024-02-09 14:22 ` Christian Brauner
2024-02-09 16:36 ` Al Viro [this message]
2024-02-12 9:59 ` Christian Brauner
2024-02-09 16:35 ` Al Viro
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=20240209163646.GD608142@ZenIV \
--to=viro@zeniv.linux.org.uk \
--cc=brauner@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=dmantipov@yandex.ru \
--cc=joel@joelfernandes.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=lvc-project@linuxtesting.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.