From: Christian Brauner <brauner@kernel.org>
To: "Seth Forshee (DigitalOcean)" <sforshee@kernel.org>
Cc: Serge Hallyn <serge@hallyn.com>, Paul Moore <paul@paul-moore.com>,
Eric Paris <eparis@redhat.com>, James Morris <jmorris@namei.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jan Kara <jack@suse.cz>,
Stephen Smalley <stephen.smalley.work@gmail.com>,
Ondrej Mosnacek <omosnace@redhat.com>,
Casey Schaufler <casey@schaufler-ca.com>,
Mimi Zohar <zohar@linux.ibm.com>,
Roberto Sassu <roberto.sassu@huawei.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
Eric Snowberg <eric.snowberg@oracle.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Jonathan Corbet <corbet@lwn.net>,
Miklos Szeredi <miklos@szeredi.hu>,
Amir Goldstein <amir73il@gmail.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org, audit@vger.kernel.org,
selinux@vger.kernel.org, linux-integrity@vger.kernel.org,
linux-doc@vger.kernel.org, linux-unionfs@vger.kernel.org
Subject: Re: [PATCH v2 17/25] fs: add vfs_get_fscaps()
Date: Fri, 23 Feb 2024 09:28:01 +0100 [thread overview]
Message-ID: <20240223-unzutreffend-streng-40cc6bcbc222@brauner> (raw)
In-Reply-To: <20240221-idmap-fscap-refactor-v2-17-3039364623bd@kernel.org>
On Wed, Feb 21, 2024 at 03:24:48PM -0600, Seth Forshee (DigitalOcean) wrote:
> Provide a type-safe interface for retrieving filesystem capabilities and
> a generic implementation suitable for most filesystems. Also add an
> internal interface, vfs_get_fscaps_nosec(), which skips security checks
> for later use from the capability code.
>
> Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
> ---
> fs/xattr.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/fs.h | 4 ++++
> 2 files changed, 68 insertions(+)
>
> diff --git a/fs/xattr.c b/fs/xattr.c
> index 06290e4ebc03..10d1b1f78fc2 100644
> --- a/fs/xattr.c
> +++ b/fs/xattr.c
> @@ -181,6 +181,70 @@ xattr_supports_user_prefix(struct inode *inode)
> }
> EXPORT_SYMBOL(xattr_supports_user_prefix);
>
> +static int generic_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
> + struct vfs_caps *caps)
> +{
> + struct inode *inode = d_inode(dentry);
> + struct vfs_ns_cap_data nscaps;
> + int ret;
> +
> + ret = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, &nscaps, sizeof(nscaps));
> +
> + if (ret >= 0)
> + ret = vfs_caps_from_xattr(idmap, i_user_ns(inode), caps, &nscaps, ret);
> +
> + return ret;
> +}
> +
> +/**
> + * vfs_get_fscaps_nosec - get filesystem capabilities without security checks
> + * @idmap: idmap of the mount the inode was found from
> + * @dentry: the dentry from which to get filesystem capabilities
> + * @caps: storage in which to return the filesystem capabilities
> + *
> + * This function gets the filesystem capabilities for the dentry and returns
> + * them in @caps. It does not perform security checks.
> + *
> + * Return: 0 on success, a negative errno on error.
> + */
> +int vfs_get_fscaps_nosec(struct mnt_idmap *idmap, struct dentry *dentry,
> + struct vfs_caps *caps)
> +{
> + struct inode *inode = d_inode(dentry);
> +
> + if (inode->i_op->get_fscaps)
> + return inode->i_op->get_fscaps(idmap, dentry, caps);
> + return generic_get_fscaps(idmap, dentry, caps);
> +}
> +
> +/**
> + * vfs_get_fscaps - get filesystem capabilities
> + * @idmap: idmap of the mount the inode was found from
> + * @dentry: the dentry from which to get filesystem capabilities
> + * @caps: storage in which to return the filesystem capabilities
> + *
> + * This function gets the filesystem capabilities for the dentry and returns
> + * them in @caps.
> + *
> + * Return: 0 on success, a negative errno on error.
> + */
> +int vfs_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
> + struct vfs_caps *caps)
> +{
> + int error;
> +
> + /*
> + * The VFS has no restrictions on reading security.* xattrs, so
> + * xattr_permission() isn't needed. Only LSMs get a say.
> + */
> + error = security_inode_get_fscaps(idmap, dentry);
> + if (error)
> + return error;
> +
> + return vfs_get_fscaps_nosec(idmap, dentry, caps);
> +}
> +EXPORT_SYMBOL(vfs_get_fscaps);
> +
> int
> __vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
> struct inode *inode, const char *name, const void *value,
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 89163e0f7aad..d7cd2467e1ea 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2116,6 +2116,10 @@ extern int vfs_dedupe_file_range(struct file *file,
> extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
> struct file *dst_file, loff_t dst_pos,
> loff_t len, unsigned int remap_flags);
> +extern int vfs_get_fscaps_nosec(struct mnt_idmap *idmap, struct dentry *dentry,
> + struct vfs_caps *caps);
> +extern int vfs_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
> + struct vfs_caps *caps);
Please drop the externs. Other than my usual complaing about this
falling back to the legacy vfs_*xattr() interfaces,
Reviewed-by: Christian Brauner <brauner@kernel.org>
next prev parent reply other threads:[~2024-02-23 8:28 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-21 21:24 [PATCH v2 00/25] fs: use type-safe uid representation for filesystem capabilities Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 01/25] mnt_idmapping: split out core vfs[ug]id_t definitions into vfsid.h Seth Forshee (DigitalOcean)
2024-02-22 14:09 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 02/25] mnt_idmapping: include cred.h Seth Forshee (DigitalOcean)
2024-02-22 14:12 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 03/25] capability: add static asserts for comapatibility of vfs_cap_data and vfs_ns_cap_data Seth Forshee (DigitalOcean)
2024-02-22 14:23 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 04/25] capability: rename cpu_vfs_cap_data to vfs_caps Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 05/25] capability: use vfsuid_t for vfs_caps rootids Seth Forshee (DigitalOcean)
2024-02-22 14:25 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 06/25] capability: provide helpers for converting between xattrs and vfs_caps Seth Forshee (DigitalOcean)
2024-02-22 15:20 ` Christian Brauner
2024-02-22 15:38 ` Seth Forshee (DigitalOcean)
2024-02-23 8:08 ` Christian Brauner
2024-03-01 16:30 ` Roberto Sassu
2024-03-01 19:00 ` Seth Forshee (DigitalOcean)
2024-03-04 8:33 ` Roberto Sassu
2024-03-04 14:24 ` Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 07/25] capability: provide a helper for converting vfs_caps to xattr for userspace Seth Forshee (DigitalOcean)
2024-02-22 15:22 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 08/25] xattr: add is_fscaps_xattr() helper Seth Forshee (DigitalOcean)
2024-02-23 8:09 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 09/25] commoncap: use is_fscaps_xattr() Seth Forshee (DigitalOcean)
2024-02-23 8:10 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 10/25] xattr: " Seth Forshee (DigitalOcean)
2024-02-23 8:10 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 11/25] security: add hooks for set/get/remove of fscaps Seth Forshee (DigitalOcean)
2024-02-21 23:31 ` Paul Moore
2024-02-22 0:07 ` Seth Forshee (DigitalOcean)
2024-02-23 8:23 ` Christian Brauner
2024-03-01 15:59 ` Roberto Sassu
2024-03-01 18:50 ` Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 12/25] selinux: add hooks for fscaps operations Seth Forshee (DigitalOcean)
2024-02-21 23:38 ` Paul Moore
2024-02-22 0:10 ` Seth Forshee (DigitalOcean)
2024-02-22 0:19 ` Paul Moore
2024-02-22 0:28 ` Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 13/25] smack: " Seth Forshee (DigitalOcean)
2024-02-21 22:52 ` Casey Schaufler
2024-02-22 0:11 ` Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 14/25] evm: add support for fscaps security hooks Seth Forshee (DigitalOcean)
2024-03-01 9:19 ` Roberto Sassu
2024-03-01 12:54 ` Christian Brauner
2024-03-01 13:19 ` Roberto Sassu
2024-03-01 13:39 ` Christian Brauner
2024-03-01 14:39 ` Seth Forshee (DigitalOcean)
2024-03-01 15:04 ` Roberto Sassu
2024-03-04 15:01 ` Roberto Sassu
2024-02-21 21:24 ` [PATCH v2 15/25] security: call evm fscaps hooks from generic " Seth Forshee (DigitalOcean)
2024-02-21 23:43 ` Paul Moore
2024-02-22 0:20 ` Seth Forshee (DigitalOcean)
2024-02-22 0:37 ` Paul Moore
2024-02-21 21:24 ` [PATCH v2 16/25] fs: add inode operations to get/set/remove fscaps Seth Forshee (DigitalOcean)
2024-02-23 8:25 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 17/25] fs: add vfs_get_fscaps() Seth Forshee (DigitalOcean)
2024-02-23 8:28 ` Christian Brauner [this message]
2024-02-21 21:24 ` [PATCH v2 18/25] fs: add vfs_set_fscaps() Seth Forshee (DigitalOcean)
2024-02-23 8:38 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 19/25] fs: add vfs_remove_fscaps() Seth Forshee (DigitalOcean)
2024-02-23 8:40 ` Christian Brauner
2024-02-21 21:24 ` [PATCH v2 20/25] ovl: add fscaps handlers Seth Forshee (DigitalOcean)
2024-02-23 9:04 ` Christian Brauner
2024-02-27 13:28 ` Amir Goldstein
2024-02-27 14:57 ` Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 21/25] ovl: use vfs_{get,set}_fscaps() for copy-up Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 22/25] fs: use vfs interfaces for capabilities xattrs Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 23/25] commoncap: remove cap_inode_getsecurity() Seth Forshee (DigitalOcean)
2024-02-21 21:24 ` [PATCH v2 24/25] commoncap: use vfs fscaps interfaces Seth Forshee (DigitalOcean)
2024-03-04 10:19 ` Roberto Sassu
2024-03-04 15:31 ` Seth Forshee (DigitalOcean)
2024-03-04 16:17 ` Roberto Sassu
2024-03-04 16:56 ` Seth Forshee (DigitalOcean)
2024-03-05 9:12 ` Christian Brauner
2024-03-05 12:46 ` Roberto Sassu
2024-03-05 16:26 ` Christian Brauner
2024-03-05 16:35 ` Roberto Sassu
2024-03-05 17:03 ` Seth Forshee (DigitalOcean)
2024-03-05 17:08 ` Roberto Sassu
2024-03-05 17:11 ` Roberto Sassu
2024-03-05 20:17 ` Seth Forshee (DigitalOcean)
2024-03-06 8:30 ` Roberto Sassu
2024-03-06 2:17 ` Mimi Zohar
2024-03-06 8:25 ` Roberto Sassu
2024-03-06 12:56 ` Mimi Zohar
2024-02-21 21:24 ` [PATCH v2 25/25] vfs: return -EOPNOTSUPP for fscaps from vfs_*xattr() Seth Forshee (DigitalOcean)
2024-02-22 15:27 ` [PATCH v2 00/25] fs: use type-safe uid representation for filesystem capabilities Christian Brauner
2024-02-22 16:28 ` Seth Forshee (DigitalOcean)
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