ocfs2: Switch to security_inode_init_security()

In preparation for removing security_old_inode_init_security(), switch to
security_inode_init_security().

Extend the existing ocfs2_initxattrs() to take the
ocfs2_security_xattr_info structure from fs_info, and populate the
name/value/len triple with the first xattr provided by LSMs.

As fs_info was not used before, ocfs2_initxattrs() can now handle the case
of replicating the behavior of security_old_inode_init_security(), i.e.
just obtaining the xattr, in addition to setting all xattrs provided by
LSMs.

Supporting multiple xattrs is not currently supported where
security_old_inode_init_security() was called (mknod, symlink), as it
requires non-trivial changes that can be done at a later time. Like for
reiserfs, even if EVM is invoked, it will not provide an xattr (if it is
not the first to set it, its xattr will be discarded; if it is the first,
it does not have xattrs to calculate the HMAC on).

Finally, since security_inode_init_security(), unlike
security_old_inode_init_security(), returns zero instead of -EOPNOTSUPP if
no xattrs were provided by LSMs or if inodes are private, additionally
check in ocfs2_init_security_get() if the xattr name is set.

If not, act as if security_old_inode_init_security() returned -EOPNOTSUPP,
and set si->enable to zero to notify to the functions following
ocfs2_init_security_get() that no xattrs are available.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Roberto Sassu 2023-03-14 09:17:16 +01:00 committed by Paul Moore
parent 52ca4b6435
commit de3004c874
2 changed files with 28 additions and 4 deletions

View File

@ -242,6 +242,7 @@ static int ocfs2_mknod(struct mnt_idmap *idmap,
int want_meta = 0;
int xattr_credits = 0;
struct ocfs2_security_xattr_info si = {
.name = NULL,
.enable = 1,
};
int did_quota_inode = 0;
@ -1805,6 +1806,7 @@ static int ocfs2_symlink(struct mnt_idmap *idmap,
int want_clusters = 0;
int xattr_credits = 0;
struct ocfs2_security_xattr_info si = {
.name = NULL,
.enable = 1,
};
int did_quota = 0, did_quota_inode = 0;

View File

@ -7259,9 +7259,21 @@ static int ocfs2_xattr_security_set(const struct xattr_handler *handler,
static int ocfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
void *fs_info)
{
struct ocfs2_security_xattr_info *si = fs_info;
const struct xattr *xattr;
int err = 0;
if (si) {
si->value = kmemdup(xattr_array->value, xattr_array->value_len,
GFP_KERNEL);
if (!si->value)
return -ENOMEM;
si->name = xattr_array->name;
si->value_len = xattr_array->value_len;
return 0;
}
for (xattr = xattr_array; xattr->name != NULL; xattr++) {
err = ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_SECURITY,
xattr->name, xattr->value,
@ -7277,13 +7289,23 @@ int ocfs2_init_security_get(struct inode *inode,
const struct qstr *qstr,
struct ocfs2_security_xattr_info *si)
{
int ret;
/* check whether ocfs2 support feature xattr */
if (!ocfs2_supports_xattr(OCFS2_SB(dir->i_sb)))
return -EOPNOTSUPP;
if (si)
return security_old_inode_init_security(inode, dir, qstr,
&si->name, &si->value,
&si->value_len);
if (si) {
ret = security_inode_init_security(inode, dir, qstr,
&ocfs2_initxattrs, si);
/*
* security_inode_init_security() does not return -EOPNOTSUPP,
* we have to check the xattr ourselves.
*/
if (!ret && !si->name)
si->enable = 0;
return ret;
}
return security_inode_init_security(inode, dir, qstr,
&ocfs2_initxattrs, NULL);