linux-stable/fs/hfsplus/xattr_security.c
Christian Brauner 39f60c1cce
fs: port xattr to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00

79 lines
2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/hfsplus/xattr_trusted.c
*
* Vyacheslav Dubeyko <slava@dubeyko.com>
*
* Handler for storing security labels as extended attributes.
*/
#include <linux/security.h>
#include <linux/nls.h>
#include "hfsplus_fs.h"
#include "xattr.h"
static int hfsplus_security_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *name, void *buffer, size_t size)
{
return hfsplus_getxattr(inode, name, buffer, size,
XATTR_SECURITY_PREFIX,
XATTR_SECURITY_PREFIX_LEN);
}
static int hfsplus_security_setxattr(const struct xattr_handler *handler,
struct mnt_idmap *idmap,
struct dentry *unused, struct inode *inode,
const char *name, const void *buffer,
size_t size, int flags)
{
return hfsplus_setxattr(inode, name, buffer, size, flags,
XATTR_SECURITY_PREFIX,
XATTR_SECURITY_PREFIX_LEN);
}
static int hfsplus_initxattrs(struct inode *inode,
const struct xattr *xattr_array,
void *fs_info)
{
const struct xattr *xattr;
char *xattr_name;
int err = 0;
xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
GFP_KERNEL);
if (!xattr_name)
return -ENOMEM;
for (xattr = xattr_array; xattr->name != NULL; xattr++) {
if (!strcmp(xattr->name, ""))
continue;
strcpy(xattr_name, XATTR_SECURITY_PREFIX);
strcpy(xattr_name +
XATTR_SECURITY_PREFIX_LEN, xattr->name);
memset(xattr_name +
XATTR_SECURITY_PREFIX_LEN + strlen(xattr->name), 0, 1);
err = __hfsplus_setxattr(inode, xattr_name,
xattr->value, xattr->value_len, 0);
if (err)
break;
}
kfree(xattr_name);
return err;
}
int hfsplus_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
return security_inode_init_security(inode, dir, qstr,
&hfsplus_initxattrs, NULL);
}
const struct xattr_handler hfsplus_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.get = hfsplus_security_getxattr,
.set = hfsplus_security_setxattr,
};