From: Amir Goldstein <amir73il@gmail.com>
To: "Seth Forshee (DigitalOcean)" <sforshee@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>,
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>,
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 20/25] ovl: add fscaps handlers
Date: Tue, 27 Feb 2024 15:28:18 +0200 [thread overview]
Message-ID: <CAOQ4uxjvrFuz2iCiO9dsOnear+qN=M+GFW-eEOZU5uCzBkTwLQ@mail.gmail.com> (raw)
In-Reply-To: <20240221-idmap-fscap-refactor-v2-20-3039364623bd@kernel.org>
On Wed, Feb 21, 2024 at 11:25 PM Seth Forshee (DigitalOcean)
<sforshee@kernel.org> wrote:
>
> Add handlers which read fs caps from the lower or upper filesystem and
> write/remove fs caps to the upper filesystem, performing copy-up as
> necessary.
>
> While fscaps only really make sense on regular files, the general policy
> is to allow most xattr namespaces on all different inode types, so
> fscaps handlers are installed in the inode operations for all types of
> inodes.
>
> Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
> ---
> fs/overlayfs/dir.c | 2 ++
> fs/overlayfs/inode.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
> fs/overlayfs/overlayfs.h | 5 ++++
> 3 files changed, 79 insertions(+)
>
> diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
> index 0f8b4a719237..4ff360fe10c9 100644
> --- a/fs/overlayfs/dir.c
> +++ b/fs/overlayfs/dir.c
> @@ -1307,6 +1307,8 @@ const struct inode_operations ovl_dir_inode_operations = {
> .get_inode_acl = ovl_get_inode_acl,
> .get_acl = ovl_get_acl,
> .set_acl = ovl_set_acl,
> + .get_fscaps = ovl_get_fscaps,
> + .set_fscaps = ovl_set_fscaps,
> .update_time = ovl_update_time,
> .fileattr_get = ovl_fileattr_get,
> .fileattr_set = ovl_fileattr_set,
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index c63b31a460be..7a8978ea6fe1 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -568,6 +568,72 @@ int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
> }
> #endif
>
> +int ovl_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
> + struct vfs_caps *caps)
> +{
> + int err;
> + const struct cred *old_cred;
> + struct path realpath;
> +
> + ovl_path_real(dentry, &realpath);
> + old_cred = ovl_override_creds(dentry->d_sb);
> + err = vfs_get_fscaps(mnt_idmap(realpath.mnt), realpath.dentry, caps);
> + revert_creds(old_cred);
> + return err;
> +}
> +
> +int ovl_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
> + const struct vfs_caps *caps, int setxattr_flags)
> +{
> + int err;
> + struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
> + struct dentry *upperdentry = ovl_dentry_upper(dentry);
> + struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry);
> + const struct cred *old_cred;
> +
> + /*
> + * If the fscaps are to be remove from a lower file, check that they
> + * exist before copying up.
> + */
Don't you need to convert -ENODATA to 0 return value in this case?
> + if (!caps && !upperdentry) {
> + struct path realpath;
> + struct vfs_caps lower_caps;
> +
> + ovl_path_lower(dentry, &realpath);
> + old_cred = ovl_override_creds(dentry->d_sb);
> + err = vfs_get_fscaps(mnt_idmap(realpath.mnt), realdentry,
> + &lower_caps);
> + revert_creds(old_cred);
> + if (err)
> + goto out;
> + }
> +
> + err = ovl_want_write(dentry);
> + if (err)
> + goto out;
> +
ovl_want_write() should after ovl_copy_up(), see:
162d06444070 ("ovl: reorder ovl_want_write() after ovl_inode_lock()")
> + err = ovl_copy_up(dentry);
> + if (err)
> + goto out_drop_write;
> + upperdentry = ovl_dentry_upper(dentry);
> +
> + old_cred = ovl_override_creds(dentry->d_sb);
> + if (!caps)
> + err = vfs_remove_fscaps(ovl_upper_mnt_idmap(ofs), upperdentry);
> + else
> + err = vfs_set_fscaps(ovl_upper_mnt_idmap(ofs), upperdentry,
> + caps, setxattr_flags);
> + revert_creds(old_cred);
> +
> + /* copy c/mtime */
> + ovl_copyattr(d_inode(dentry));
> +
> +out_drop_write:
> + ovl_drop_write(dentry);
> +out:
> + return err;
> +}
> +
> int ovl_update_time(struct inode *inode, int flags)
> {
> if (flags & S_ATIME) {
> @@ -747,6 +813,8 @@ static const struct inode_operations ovl_file_inode_operations = {
> .get_inode_acl = ovl_get_inode_acl,
> .get_acl = ovl_get_acl,
> .set_acl = ovl_set_acl,
> + .get_fscaps = ovl_get_fscaps,
> + .set_fscaps = ovl_set_fscaps,
> .update_time = ovl_update_time,
> .fiemap = ovl_fiemap,
> .fileattr_get = ovl_fileattr_get,
> @@ -758,6 +826,8 @@ static const struct inode_operations ovl_symlink_inode_operations = {
> .get_link = ovl_get_link,
> .getattr = ovl_getattr,
> .listxattr = ovl_listxattr,
> + .get_fscaps = ovl_get_fscaps,
> + .set_fscaps = ovl_set_fscaps,
> .update_time = ovl_update_time,
> };
>
> @@ -769,6 +839,8 @@ static const struct inode_operations ovl_special_inode_operations = {
> .get_inode_acl = ovl_get_inode_acl,
> .get_acl = ovl_get_acl,
> .set_acl = ovl_set_acl,
> + .get_fscaps = ovl_get_fscaps,
> + .set_fscaps = ovl_set_fscaps,
> .update_time = ovl_update_time,
> };
>
Sorry, I did not understand the explanation why fscaps ops are needed
for non regular files. It does not look right to me.
Thanks,
Amir.
next prev parent reply other threads:[~2024-02-27 13:28 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
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 [this message]
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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