Roberto Sassu
2022-Nov-23 09:51 UTC
[Ocfs2-devel] [PATCH v5 2/6] ocfs2: Switch to security_inode_init_security()
From: Roberto Sassu <roberto.sassu at 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. Supporting
multiple xattrs is not currently supported, as it requires non-trivial
changes that can be done at a later time.
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.
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 at huawei.com>
---
fs/ocfs2/namei.c | 18 ++++++------------
fs/ocfs2/xattr.c | 30 ++++++++++++++++++++++++++----
2 files changed, 32 insertions(+), 16 deletions(-)
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 05f32989bad6..55fba81cd2d1 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -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 */
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 95d0611c5fc7..55699c573541 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -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);
--
2.25.1
Mimi Zohar
2022-Nov-23 17:46 UTC
[Ocfs2-devel] [PATCH v5 2/6] ocfs2: Switch to security_inode_init_security()
On Wed, 2022-11-23 at 10:51 +0100, Roberto Sassu wrote:> From: Roberto Sassu <roberto.sassu at 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. Supporting > multiple xattrs is not currently supported, as it requires non-trivial > changes that can be done at a later time.ocfs2 already defines ocfs2_init_security_get() as a wrapper around calling either security_old_inode_init_security() or security_inode_init_security(). Based on "si" one or the other hook is called. ocfs2_initxattrs is already defined. struct ocfs2_security_xattr_info si = { .name = NULL, .enable = 1, }; The main difference between calling security_old_inode_init_security or security_inode_init_security() is whether or not security.evm is calculated and written. Perhaps it is time to remove the call to security_old_inode_init_security() in ocfs2_init_security_get(). We need to hear back from the ocfs2 community. Mark? Joel? As noted previously this change affects mknod and symlinks. Mimi> > 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. > > 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 at huawei.com> > --- > fs/ocfs2/namei.c | 18 ++++++------------ > fs/ocfs2/xattr.c | 30 ++++++++++++++++++++++++++---- > 2 files changed, 32 insertions(+), 16 deletions(-) > > diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c > index 05f32989bad6..55fba81cd2d1 100644 > --- a/fs/ocfs2/namei.c > +++ b/fs/ocfs2/namei.c > @@ -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 */ > diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c > index 95d0611c5fc7..55699c573541 100644 > --- a/fs/ocfs2/xattr.c > +++ b/fs/ocfs2/xattr.c > @@ -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);