Option 2:
In preparation for supporting the initialization of multiple LSM xattrs
and the EVM xattr, this patch defines an xattr structure and changes
the security_inode_init_security API, adding an fs specific function
callback parameter to write the xattrs.
Initially the callback function walks the array of xattrs, calling the
xattr 'set' function for each xattr. To optimize performance an FS could
replace this, with one that writes the multiple xattrs in a single 'set'
call.
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxx>
---
fs/ext3/xattr_security.c | 36 ++++++++++++++++++++----------------
fs/ext4/xattr_security.c | 36 ++++++++++++++++++++----------------
include/linux/security.h | 20 +++++++++++++++-----
include/linux/xattr.h | 6 ++++++
mm/shmem.c | 4 ++--
security/security.c | 36 +++++++++++++++++++++++++++++++-----
6 files changed, 94 insertions(+), 44 deletions(-)
diff --git a/fs/ext3/xattr_security.c b/fs/ext3/xattr_security.c
index b8d9f83..1ceaad6d 100644
--- a/fs/ext3/xattr_security.c
+++ b/fs/ext3/xattr_security.c
@@ -48,26 +48,30 @@ ext3_xattr_security_set(struct dentry *dentry, const char *name,
name, value, size, flags);
}
+int ext3_initxattrs(struct inode *inode, struct xattr *xattr_array, int flag,
+ void *fs_info)
+{
+ handle_t *handle = fs_info;
+ struct xattr *xattr;
+ int err = 0;
+
+ for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+ err = ext3_xattr_set_handle(handle, inode,
+ EXT3_XATTR_INDEX_SECURITY,
+ xattr->name, xattr->value,
+ xattr->value_len, 0);
+ if (err < 0)
+ break;
+ }
+ return err;
+}
+
int
ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
- int err;
- size_t len;
- void *value;
- char *name;
-
- err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
- if (err) {
- if (err == -EOPNOTSUPP)
- return 0;
- return err;
- }
- err = ext3_xattr_set_handle(handle, inode, EXT3_XATTR_INDEX_SECURITY,
- name, value, len, 0);
- kfree(name);
- kfree(value);
- return err;
+ return security_inode_init_security(inode, dir, qstr,
+ &ext3_initxattrs, handle);
}
const struct xattr_handler ext3_xattr_security_handler = {
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 007c3bf..3a97aaa 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -48,26 +48,30 @@ ext4_xattr_security_set(struct dentry *dentry, const char *name,
name, value, size, flags);
}
+int ext4_initxattrs(struct inode *inode, struct xattr *xattr_array, int flag,
+ void *fs_info)
+{
+ handle_t *handle = fs_info;
+ struct xattr *xattr;
+ int err = 0;
+
+ for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+ err = ext4_xattr_set_handle(handle, inode,
+ EXT4_XATTR_INDEX_SECURITY,
+ xattr->name, xattr->value,
+ xattr->value_len, 0);
+ if (err < 0)
+ break;
+ }
+ return err;
+}
+
int
ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
- int err;
- size_t len;
- void *value;
- char *name;
-
- err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
- if (err) {
- if (err == -EOPNOTSUPP)
- return 0;
- return err;
- }
- err = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_SECURITY,
- name, value, len, 0);
- kfree(name);
- kfree(value);
- return err;
+ return security_inode_init_security(inode, dir, qstr,
+ &ext4_initxattrs, handle);
}
const struct xattr_handler ext4_xattr_security_handler = {
diff --git a/include/linux/security.h b/include/linux/security.h
index 8ce59ef..92cbf8d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -36,6 +36,7 @@
#include <linux/key.h>
#include <linux/xfrm.h>
#include <linux/slab.h>
+#include <linux/xattr.h>
#include <net/flow.h>
/* Maximum number of letters for an LSM name string */
@@ -1704,8 +1705,12 @@ int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts);
int security_inode_alloc(struct inode *inode);
void security_inode_free(struct inode *inode);
int security_inode_init_security(struct inode *inode, struct inode *dir,
- const struct qstr *qstr, char **name,
- void **value, size_t *len);
+ const struct qstr *qstr,
+ int (*initxattrs) (struct inode *inode,
+ struct xattr *xattr_array, int flag,
+ void *fs_data),
+ void *fs_data
+ );
int security_inode_create(struct inode *dir, struct dentry *dentry, int mode);
int security_inode_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry);
@@ -2035,9 +2040,14 @@ static inline void security_inode_free(struct inode *inode)
static inline int security_inode_init_security(struct inode *inode,
struct inode *dir,
const struct qstr *qstr,
- char **name,
- void **value,
- size_t *len)
+ struct xattr **xattr_array)
+ int (*initxattrs)
+ (struct inode *inode,
+ struct xattr *xattr_array,
+ int flag,
+ void *fs_data),
+ void *fs_data
+ );
{
return -EOPNOTSUPP;
}
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index aed54c5..7a37866 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -67,6 +67,12 @@ struct xattr_handler {
size_t size, int flags, int handler_flags);
};
+struct xattr {
+ char *name;
+ void *value;
+ size_t value_len;
+};
+
ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
diff --git a/mm/shmem.c b/mm/shmem.c
index d221a1c..518f27c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1877,7 +1877,7 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
if (inode) {
error = security_inode_init_security(inode, dir,
- &dentry->d_name, NULL,
+ &dentry->d_name,
NULL, NULL);
if (error) {
if (error != -EOPNOTSUPP) {
@@ -2017,7 +2017,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
if (!inode)
return -ENOSPC;
- error = security_inode_init_security(inode, dir, &dentry->d_name, NULL,
+ error = security_inode_init_security(inode, dir, &dentry->d_name,
NULL, NULL);
if (error) {
if (error != -EOPNOTSUPP) {
diff --git a/security/security.c b/security/security.c
index 4ba6d4c..c1ad1d2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -18,6 +18,8 @@
#include <linux/security.h>
#include <linux/ima.h>
+#define MAX_LSM_XATTR 1
+
/* Boot-time LSM user choice */
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
CONFIG_DEFAULT_SECURITY;
@@ -339,13 +341,37 @@ void security_inode_free(struct inode *inode)
}
int security_inode_init_security(struct inode *inode, struct inode *dir,
- const struct qstr *qstr, char **name,
- void **value, size_t *len)
-{
+ const struct qstr *qstr,
+ int (*initxattrs) (struct inode *inode,
+ struct xattr *xattr_array, int flag,
+ void *fs_data),
+ void *fs_data
+ )
+{
+ struct xattr new_xattrs[MAX_LSM_XATTR + 1];
+ struct xattr *lsm_xattr;
+ int ret;
+
if (unlikely(IS_PRIVATE(inode)))
return -EOPNOTSUPP;
- return security_ops->inode_init_security(inode, dir, qstr, name, value,
- len);
+
+ memset(new_xattrs, 0, sizeof new_xattrs);
+ if (!initxattrs)
+ return security_ops->inode_init_security(inode, dir, qstr,
+ NULL, NULL, NULL);
+ lsm_xattr = new_xattrs;
+ ret = security_ops->inode_init_security(inode, dir, qstr,
+ &lsm_xattr->name,
+ &lsm_xattr->value,
+ &lsm_xattr->value_len);
+ if (ret)
+ goto out;
+ ret = initxattrs(inode, new_xattrs, 0, fs_data);
+out:
+ kfree(lsm_xattr->name);
+ kfree(lsm_xattr->value);
+
+ return (ret == -EOPNOTSUPP) ? 0 : ret;
}
EXPORT_SYMBOL(security_inode_init_security);
--
1.7.3.4
--
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