LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: "Tobin C. Harding" <tobin@kernel.org>
Cc: Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
	David Sterba <dsterba@suse.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] fs: btrfs: Don't leak memory when failing add fsid
Date: Mon, 13 May 2019 09:12:21 +0200	[thread overview]
Message-ID: <20190513071221.GE2868@kroah.com> (raw)
In-Reply-To: <20190513033912.3436-3-tobin@kernel.org>

On Mon, May 13, 2019 at 01:39:12PM +1000, Tobin C. Harding wrote:
> A failed call to kobject_init_and_add() must be followed by a call to
> kobject_put().  Currently in the error path when adding fs_devices we
> are missing this call.  This could be fixed by calling
> btrfs_sysfs_remove_fsid() if btrfs_sysfs_add_fsid() returns an error or
> by adding a call to kobject_put() directly in btrfs_sysfs_add_fsid().
> Here we choose the second option because it prevents the slightly
> unusual error path handling requirements of kobject from leaking out
> into btrfs functions.
> 
> Add a call to kobject_put() in the error path of kobject_add_and_init().
> This causes the release method to be called if kobject_init_and_add()
> fails.  open_tree() is the function that calls btrfs_sysfs_add_fsid()
> and the error code in this function is already written with the
> assumption that the release method is called during the error path of
> open_tree() (as seen by the call to btrfs_sysfs_remove_fsid() under the
> fail_fsdev_sysfs label).
> 
> Signed-off-by: Tobin C. Harding <tobin@kernel.org>
> ---
>  fs/btrfs/sysfs.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
> index 5a5930e3d32b..2f078b77fe14 100644
> --- a/fs/btrfs/sysfs.c
> +++ b/fs/btrfs/sysfs.c
> @@ -825,7 +825,12 @@ int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
>  	fs_devs->fsid_kobj.kset = btrfs_kset;
>  	error = kobject_init_and_add(&fs_devs->fsid_kobj,
>  				&btrfs_ktype, parent, "%pU", fs_devs->fsid);
> -	return error;
> +	if (error) {
> +		kobject_put(&fs_devs->fsid_kobj);
> +		return error;
> +	}
> +
> +	return 0;
>  }
>  
>  int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

  parent reply	other threads:[~2019-05-13  7:12 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-13  3:39 [PATCH 0/2] Fix kobject error path memleaks Tobin C. Harding
2019-05-13  3:39 ` [PATCH 1/2] fs: btrfs: Fix error path kobject memory leak Tobin C. Harding
2019-05-13  5:59   ` Nikolay Borisov
2019-05-13  7:11     ` Greg Kroah-Hartman
2019-05-13  3:39 ` [PATCH 2/2] fs: btrfs: Don't leak memory when failing add fsid Tobin C. Harding
2019-05-13  6:04   ` Nikolay Borisov
2019-05-13 10:57     ` Tobin C. Harding
2019-05-13  7:12   ` Greg Kroah-Hartman [this message]
2019-05-13 17:47 ` [PATCH 0/2] Fix kobject error path memleaks David Sterba

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=20190513071221.GE2868@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=clm@fb.com \
    --cc=dsterba@suse.com \
    --cc=josef@toxicpanda.com \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rafael@kernel.org \
    --cc=tobin@kernel.org \
    --subject='Re: [PATCH 2/2] fs: btrfs: Don'\''t leak memory when failing add fsid' \
    /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

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).