[v6,2/6] ocfs2: Switch to security_inode_init_security()
Commit Message
From: Roberto Sassu <roberto.sassu@huawei.com>
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, modify the handling of the return value from
ocfs2_init_security_get(). As security_inode_init_security() does not
return -EOPNOTSUPP, remove this case and directly handle the error if the
return value is not zero.
However, the previous case of receiving -EOPNOTSUPP should be still
taken into account, as security_inode_init_security() could return zero
without setting xattrs and ocfs2 would consider it as if the xattr was set.
Instead, if security_inode_init_security() returned zero, look at the xattr
if it was set, and behave accordingly, i.e. set si->enable to zero to
notify to the functions following ocfs2_init_security_get() that the xattr
is not available (same as if security_old_inode_init_security() returned
-EOPNOTSUPP).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
fs/ocfs2/namei.c | 18 ++++++------------
fs/ocfs2/xattr.c | 30 ++++++++++++++++++++++++++----
2 files changed, 32 insertions(+), 16 deletions(-)
@@ -242,6 +242,7 @@ static int ocfs2_mknod(struct user_namespace *mnt_userns,
int want_meta = 0;
int xattr_credits = 0;
struct ocfs2_security_xattr_info si = {
+ .name = NULL,
.enable = 1,
};
int did_quota_inode = 0;
@@ -315,12 +316,8 @@ static int ocfs2_mknod(struct user_namespace *mnt_userns,
/* get security xattr */
status = ocfs2_init_security_get(inode, dir, &dentry->d_name, &si);
if (status) {
- if (status == -EOPNOTSUPP)
- si.enable = 0;
- else {
- mlog_errno(status);
- goto leave;
- }
+ mlog_errno(status);
+ goto leave;
}
/* calculate meta data/clusters for setting security and acl xattr */
@@ -1805,6 +1802,7 @@ static int ocfs2_symlink(struct user_namespace *mnt_userns,
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;
@@ -1875,12 +1873,8 @@ static int ocfs2_symlink(struct user_namespace *mnt_userns,
/* get security xattr */
status = ocfs2_init_security_get(inode, dir, &dentry->d_name, &si);
if (status) {
- if (status == -EOPNOTSUPP)
- si.enable = 0;
- else {
- mlog_errno(status);
- goto bail;
- }
+ mlog_errno(status);
+ goto bail;
}
/* calculate meta data/clusters for setting security xattr */
@@ -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);