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From: Will Rosenberg <whrosenb@asu.edu>
To: Paul Moore <paul@paul-moore.com>
Cc: Oliver Rosenberg <olrose55@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Tejun Heo <tj@kernel.org>,
	Casey Schaufler <casey@schaufler-ca.com>,
	Ondrej Mosnacek <omosnace@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] kernfs: fix memory leak of kernfs_iattrs in __kernfs_new_node
Date: Tue, 25 Nov 2025 08:11:40 -0700	[thread overview]
Message-ID: <aSXHLOdujmeUDELo@gmail.com> (raw)
In-Reply-To: <CAHC9VhRwBmC+8iMk8rFbDdwCy+=_unNMybC=HQN=+v5v-nkE8g@mail.gmail.com>

On Mon, Nov 24, 2025 at 03:41:51PM -0500, Paul Moore wrote:
>
> Should this be kmem_cache_free(kernfs_iattrs_cache, kn->iattr)
> instead?  I suspect it would also probably be a good idea to call
> simple_xattrs_free() first.
>
> I also noticed there is a reasonable amount of duplicated kernfs
> cleanup code spread around fs/kernfs/dir.c, we could probably benefit
> from some helper functions here, but that would be a follow-on patch;
> keeping a small bugfix patch to ease stable tree backporting is a good
> thing.

I agree. Helper functions could also help prevent this type of bug from
re-emerging.

> [HINT FOR THE FUTURE: for patches like this, look for a function that
> normally does resource cleanup for the object and do what it does, in
> this case kernfs_free_rcu() is a good example.]

Thank you for all the help. I updated kfree to kmem_cache_free() and
added simple_xattrs_free() just to be safe for future changes.

--
will rosenberg

  reply	other threads:[~2025-11-25 15:11 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-24 16:02 [PATCH v2] kernfs: fix memory leak of kernfs_iattrs in __kernfs_new_node Will Rosenberg
2025-11-24 16:15 ` Greg Kroah-Hartman
2025-11-24 18:37   ` [PATCH v3] " Will Rosenberg
2025-11-24 20:41     ` Paul Moore
2025-11-25 15:11       ` Will Rosenberg [this message]
2025-11-25 15:13       ` [PATCH v4] " Will Rosenberg
2025-12-07 21:45         ` Paul Moore
2025-12-07 22:28           ` Will Rosenberg
2025-12-07 22:38             ` Paul Moore

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