From: "Seth Forshee (DigitalOcean)" <sforshee@kernel.org>
To: Christian Brauner <brauner@kernel.org>,
Seth Forshee <sforshee@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>,
Amir Goldstein <amir73il@gmail.com>
Cc: 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: [PATCH v2 19/25] fs: add vfs_remove_fscaps()
Date: Wed, 21 Feb 2024 15:24:50 -0600 [thread overview]
Message-ID: <20240221-idmap-fscap-refactor-v2-19-3039364623bd@kernel.org> (raw)
In-Reply-To: <20240221-idmap-fscap-refactor-v2-0-3039364623bd@kernel.org>
Provide a type-safe interface for removing filesystem capabilities and a
generic implementation suitable for most filesystems. Also add an
internal interface, vfs_remove_fscaps_nosec(), which is called with the
inode lock held and skips security checks for later use from the
capability code.
Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
---
fs/xattr.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/fs.h | 2 ++
2 files changed, 83 insertions(+)
diff --git a/fs/xattr.c b/fs/xattr.c
index 96de43928a51..8b0f7384cbc9 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -324,6 +324,87 @@ int vfs_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
}
EXPORT_SYMBOL(vfs_set_fscaps);
+static int generic_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry)
+{
+ return __vfs_removexattr(idmap, dentry, XATTR_NAME_CAPS);
+}
+
+/**
+ * vfs_remove_fscaps_nosec - remove filesystem capabilities without
+ * security checks
+ * @idmap: idmap of the mount the inode was found from
+ * @dentry: the dentry from which to remove filesystem capabilities
+ *
+ * This function removes any filesystem capabilities from the specified
+ * dentry. Does not perform any security checks, and callers must hold the
+ * inode lock.
+ *
+ * Return: 0 on success, a negative errno on error.
+ */
+int vfs_remove_fscaps_nosec(struct mnt_idmap *idmap, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ if (inode->i_op->set_fscaps)
+ error = inode->i_op->set_fscaps(idmap, dentry, NULL,
+ XATTR_REPLACE);
+ else
+ error = generic_remove_fscaps(idmap, dentry);
+
+ return error;
+}
+
+/**
+ * vfs_remove_fscaps - remove filesystem capabilities
+ * @idmap: idmap of the mount the inode was found from
+ * @dentry: the dentry from which to remove filesystem capabilities
+ *
+ * This function removes any filesystem capabilities from the specified
+ * dentry.
+ *
+ * Return: 0 on success, a negative errno on error.
+ */
+int vfs_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ struct inode *delegated_inode = NULL;
+ int error;
+
+retry_deleg:
+ inode_lock(inode);
+
+ error = xattr_permission(idmap, inode, XATTR_NAME_CAPS, MAY_WRITE);
+ if (error)
+ goto out_inode_unlock;
+
+ error = security_inode_remove_fscaps(idmap, dentry);
+ if (error)
+ goto out_inode_unlock;
+
+ error = try_break_deleg(inode, &delegated_inode);
+ if (error)
+ goto out_inode_unlock;
+
+ error = vfs_remove_fscaps_nosec(idmap, dentry);
+ if (!error) {
+ fsnotify_xattr(dentry);
+ evm_inode_post_remove_fscaps(dentry);
+ }
+
+out_inode_unlock:
+ inode_unlock(inode);
+
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
+
+ return error;
+}
+EXPORT_SYMBOL(vfs_remove_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 4f5d7ed44644..c07427d2fc71 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2122,6 +2122,8 @@ extern int vfs_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
struct vfs_caps *caps);
extern int vfs_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry,
const struct vfs_caps *caps, int setxattr_flags);
+extern int vfs_remove_fscaps_nosec(struct mnt_idmap *idmap, struct dentry *dentry);
+extern int vfs_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry);
/**
* enum freeze_holder - holder of the freeze
--
2.43.0
next prev parent reply other threads:[~2024-02-21 21:25 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 ` Seth Forshee (DigitalOcean) [this message]
2024-02-23 8:40 ` [PATCH v2 19/25] fs: add vfs_remove_fscaps() 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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