From: Christian Brauner <christian.brauner@ubuntu.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jens Axboe <axboe@kernel.dk>, Tejun Heo <tj@kernel.org>,
linux-block@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 07/13] sysfs: add ->seq_show support to sysfs_ops
Date: Mon, 13 Sep 2021 15:30:57 +0200 [thread overview]
Message-ID: <20210913133057.jecjno7uswlvfdu2@wittgenstein> (raw)
In-Reply-To: <20210913054121.616001-8-hch@lst.de>
On Mon, Sep 13, 2021 at 07:41:15AM +0200, Christoph Hellwig wrote:
> Allow attributes to directly use the seq_file method instead of
> carving out a buffer that can easily lead to buffer overflows.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
> fs/sysfs/file.c | 19 ++++++++++++++-----
> include/linux/sysfs.h | 9 +++++++--
> 2 files changed, 21 insertions(+), 7 deletions(-)
>
> diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
> index 42dcf96881b68..12e0bfe40a2b4 100644
> --- a/fs/sysfs/file.c
> +++ b/fs/sysfs/file.c
> @@ -45,6 +45,9 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
> ssize_t count;
> char *buf;
>
> + if (ops->seq_show)
> + return ops->seq_show(kobj, of->kn->priv, sf);
> +
> if (WARN_ON_ONCE(!ops->show))
> return -EINVAL;
>
> @@ -268,6 +271,10 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent,
> return -EINVAL;
>
> if (mode & SYSFS_PREALLOC) {
> + if (WARN(sysfs_ops->seq_show, KERN_ERR
> + "seq_show not supported on prealloc file: %s\n",
> + kobject_name(kobj)))
> + return -EINVAL;
> if (sysfs_ops->show && sysfs_ops->store)
> ops = &sysfs_prealloc_kfops_rw;
> else if (sysfs_ops->show)
> @@ -275,12 +282,14 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent,
> else if (sysfs_ops->store)
> ops = &sysfs_prealloc_kfops_wo;
> } else {
> - if (sysfs_ops->show && sysfs_ops->store)
> - ops = &sysfs_file_kfops_rw;
> - else if (sysfs_ops->show)
> - ops = &sysfs_file_kfops_ro;
> - else if (sysfs_ops->store)
> + if (sysfs_ops->seq_show || sysfs_ops->show) {
> + if (sysfs_ops->store)
> + ops = &sysfs_file_kfops_rw;
> + else
> + ops = &sysfs_file_kfops_ro;
> + } else if (sysfs_ops->store) {
> ops = &sysfs_file_kfops_wo;
> + }
> }
>
> if (!ops)
> diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
> index e3f1e8ac1f85b..e1ab4da716730 100644
> --- a/include/linux/sysfs.h
> +++ b/include/linux/sysfs.h
> @@ -236,8 +236,13 @@ struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size)
> struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
>
> struct sysfs_ops {
> - ssize_t (*show)(struct kobject *, struct attribute *, char *);
> - ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t);
> + int (*seq_show)(struct kobject *kobj, struct attribute *attr,
> + struct seq_file *sf);
> + ssize_t (*store)(struct kobject *kobj, struct attribute *attr,
> + const char *buf, size_t size);
> +
> + /* deprecated except for preallocated attributes: */
> + ssize_t (*show)(struct kobject *kob, struct attribute *attr, char *buf);
> };
>
> #ifdef CONFIG_SYSFS
> --
> 2.30.2
>
next prev parent reply other threads:[~2021-09-13 13:44 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 5:41 start switching sysfs attributes to expose the seq_file Christoph Hellwig
2021-09-13 5:41 ` [PATCH 01/13] seq_file: mark seq_get_buf as deprecated Christoph Hellwig
2021-09-13 13:19 ` Christian Brauner
2021-09-13 16:22 ` Daniel Wagner
2021-09-13 16:29 ` Tejun Heo
2021-09-13 5:41 ` [PATCH 02/13] kernfs: remove kernfs_create_file and kernfs_create_file_ns Christoph Hellwig
2021-09-13 13:20 ` Christian Brauner
2021-09-13 5:41 ` [PATCH 03/13] kernfs: remove the unused lockdep_key field in struct kernfs_ops Christoph Hellwig
2021-09-13 13:21 ` Christian Brauner
2021-09-13 16:30 ` Tejun Heo
2021-09-13 5:41 ` [PATCH 04/13] sysfs: split out binary attribute handling from sysfs_add_file_mode_ns Christoph Hellwig
2021-09-13 13:26 ` Christian Brauner
2021-09-13 5:41 ` [PATCH 05/13] sysfs: refactor sysfs_add_file_mode_ns Christoph Hellwig
2021-09-13 13:27 ` Christian Brauner
2021-09-13 5:41 ` [PATCH 06/13] sysfs: simplify sysfs_kf_seq_show Christoph Hellwig
2021-09-13 5:41 ` [PATCH 07/13] sysfs: add ->seq_show support to sysfs_ops Christoph Hellwig
2021-09-13 13:30 ` Christian Brauner [this message]
2021-09-13 5:41 ` [PATCH 08/13] block: convert the blk_mq_hw_ctx attrs to use ->seq_show Christoph Hellwig
2021-09-13 5:41 ` [PATCH 09/13] block: convert the blk_integrity " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 10/13] block: convert the request_queue " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 11/13] block: convert the elevator_queue " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 12/13] xfs: convert xfs_errortag " Christoph Hellwig
2021-09-13 5:41 ` [PATCH 13/13] xfs: convert xfs_sysfs " Christoph Hellwig
2021-09-13 6:27 ` Greg Kroah-Hartman
2021-09-14 1:20 ` Dave Chinner
2021-09-14 5:12 ` Greg Kroah-Hartman
2021-09-14 10:56 ` Dave Chinner
2021-09-14 7:30 ` Christoph Hellwig
2021-09-14 15:28 ` Greg Kroah-Hartman
2021-09-14 15:30 ` Christoph Hellwig
2021-09-14 15:41 ` Greg Kroah-Hartman
2021-09-15 7:04 ` Christoph Hellwig
2021-09-15 7:07 ` Greg Kroah-Hartman
2021-09-13 16:39 ` start switching sysfs attributes to expose the seq_file Bart Van Assche
2021-09-13 16:46 ` Greg Kroah-Hartman
2021-09-14 2:53 ` Bart Van Assche
2021-09-13 16:46 ` Tejun Heo
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