This patch against 2.5.67 implements changes to the LSM xattr-related
hooks and adds xattr handlers for ext[23] to support the use of extended
attributes by security modules for storing file security labels, as
described in my April 8th RFC posting. I believe that I have responded
to all questions and objections that were raised in response to the RFC,
so I would ask that this patch be applied. The original RFC only
included an xattr handler for ext3; this patch also includes an xattr
handler for ext2 for consistency. If desired, I can split this into
separate patches for ext2, ext3, and the changes to the LSM
xattr-related hooks.
fs/Kconfig | 24 +++++++++++++++++++++
fs/ext2/Makefile | 4 +++
fs/ext2/xattr.c | 21 ++++++++++++++++--
fs/ext2/xattr.h | 2 +
fs/ext2/xattr_security.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++
fs/ext3/Makefile | 4 +++
fs/ext3/xattr.c | 21 ++++++++++++++++--
fs/ext3/xattr.h | 2 +
fs/ext3/xattr_security.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++
fs/xattr.c | 7 +++---
include/linux/security.h | 15 +++++++++++++
security/dummy.c | 6 +++++
12 files changed, 200 insertions(+), 9 deletions(-)
Index: linux-2.5/fs/Kconfig
diff -u linux-2.5/fs/Kconfig:1.1.1.3 linux-2.5/fs/Kconfig:1.5
--- linux-2.5/fs/Kconfig:1.1.1.3 Tue Mar 25 09:36:05 2003
+++ linux-2.5/fs/Kconfig Fri Apr 18 12:16:24 2003
@@ -73,6 +73,18 @@
If you don't know what Access Control Lists are, say N
+config EXT2_FS_SECURITY
+ bool "Ext2 Security Labels"
+ depends on EXT2_FS_XATTR
+ help
+ Security labels support alternative access control models
+ implemented by security modules like SELinux. This option
+ enables an extended attribute handler for file security
+ labels in the ext2 filesystem.
+
+ If you are not using a security module that requires using
+ extended attributes for file security labels, say N.
+
config EXT3_FS
tristate "Ext3 journalling file system support"
help
@@ -130,6 +142,18 @@
Linux website <http://acl.bestbits.at/>.
If you don't know what Access Control Lists are, say N
+
+config EXT3_FS_SECURITY
+ bool "Ext3 Security Labels"
+ depends on EXT3_FS_XATTR
+ help
+ Security labels support alternative access control models
+ implemented by security modules like SELinux. This option
+ enables an extended attribute handler for file security
+ labels in the ext3 filesystem.
+
+ If you are not using a security module that requires using
+ extended attributes for file security labels, say N.
config JBD
# CONFIG_JBD could be its own option (even modular), but until there are
Index: linux-2.5/fs/xattr.c
diff -u linux-2.5/fs/xattr.c:1.1.1.1 linux-2.5/fs/xattr.c:1.4
--- linux-2.5/fs/xattr.c:1.1.1.1 Wed Mar 12 10:55:12 2003
+++ linux-2.5/fs/xattr.c Wed Mar 26 14:03:25 2003
@@ -79,15 +79,16 @@
error = -EOPNOTSUPP;
if (d->d_inode->i_op && d->d_inode->i_op->setxattr) {
+ down(&d->d_inode->i_sem);
error = security_inode_setxattr(d, kname, kvalue, size, flags);
if (error)
goto out;
- down(&d->d_inode->i_sem);
error = d->d_inode->i_op->setxattr(d, kname, kvalue, size, flags);
+ if (!error)
+ security_inode_post_setxattr(d, kname, kvalue, size, flags);
+out:
up(&d->d_inode->i_sem);
}
-
-out:
xattr_free(kvalue, size);
return error;
}
Index: linux-2.5/fs/ext2/Makefile
diff -u linux-2.5/fs/ext2/Makefile:1.1.1.1 linux-2.5/fs/ext2/Makefile:1.2
--- linux-2.5/fs/ext2/Makefile:1.1.1.1 Wed Mar 12 10:55:33 2003
+++ linux-2.5/fs/ext2/Makefile Fri Apr 18 12:16:34 2003
@@ -14,3 +14,7 @@
ifeq ($(CONFIG_EXT2_FS_POSIX_ACL),y)
ext2-objs += acl.o
endif
+
+ifeq ($(CONFIG_EXT2_FS_SECURITY),y)
+ext2-objs += xattr_security.o
+endif
Index: linux-2.5/fs/ext2/xattr.c
diff -u linux-2.5/fs/ext2/xattr.c:1.1.1.3 linux-2.5/fs/ext2/xattr.c:1.2
--- linux-2.5/fs/ext2/xattr.c:1.1.1.3 Tue Mar 25 09:37:24 2003
+++ linux-2.5/fs/ext2/xattr.c Fri Apr 18 12:16:34 2003
@@ -1101,22 +1101,33 @@
&ext2_xattr_trusted_handler);
if (err)
goto out;
+#ifdef CONFIG_EXT2_FS_SECURITY
+ err = ext2_xattr_register(EXT2_XATTR_INDEX_SECURITY,
+ &ext2_xattr_security_handler);
+ if (err)
+ goto out1;
+#endif
#ifdef CONFIG_EXT2_FS_POSIX_ACL
err = init_ext2_acl();
if (err)
- goto out1;
+ goto out2;
#endif
ext2_xattr_cache = mb_cache_create("ext2_xattr", NULL,
sizeof(struct mb_cache_entry) +
sizeof(struct mb_cache_entry_index), 1, 6);
if (!ext2_xattr_cache) {
err = -ENOMEM;
- goto out2;
+ goto out3;
}
return 0;
-out2:
+out3:
#ifdef CONFIG_EXT2_FS_POSIX_ACL
exit_ext2_acl();
+out2:
+#endif
+#ifdef CONFIG_EXT2_FS_SECURITY
+ ext2_xattr_unregister(EXT2_XATTR_INDEX_SECURITY,
+ &ext2_xattr_security_handler);
out1:
#endif
ext2_xattr_unregister(EXT2_XATTR_INDEX_TRUSTED,
@@ -1133,6 +1144,10 @@
mb_cache_destroy(ext2_xattr_cache);
#ifdef CONFIG_EXT2_FS_POSIX_ACL
exit_ext2_acl();
+#endif
+#ifdef CONFIG_EXT2_FS_SECURITY
+ ext2_xattr_unregister(EXT2_XATTR_INDEX_SECURITY,
+ &ext2_xattr_security_handler);
#endif
ext2_xattr_unregister(EXT2_XATTR_INDEX_TRUSTED,
&ext2_xattr_trusted_handler);
Index: linux-2.5/fs/ext2/xattr.h
diff -u linux-2.5/fs/ext2/xattr.h:1.1.1.1 linux-2.5/fs/ext2/xattr.h:1.2
--- linux-2.5/fs/ext2/xattr.h:1.1.1.1 Wed Mar 12 10:55:33 2003
+++ linux-2.5/fs/ext2/xattr.h Fri Apr 18 12:16:34 2003
@@ -22,6 +22,7 @@
#define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2
#define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3
#define EXT2_XATTR_INDEX_TRUSTED 4
+#define EXT2_XATTR_INDEX_SECURITY 5
struct ext2_xattr_header {
__u32 h_magic; /* magic number for identification */
@@ -134,4 +135,5 @@
extern struct ext2_xattr_handler ext2_xattr_user_handler;
extern struct ext2_xattr_handler ext2_xattr_trusted_handler;
+extern struct ext2_xattr_handler ext2_xattr_security_handler;
Index: linux-2.5/fs/ext2/xattr_security.c
diff -u /dev/null linux-2.5/fs/ext2/xattr_security.c:1.1
--- /dev/null Fri Apr 18 12:31:13 2003
+++ linux-2.5/fs/ext2/xattr_security.c Fri Apr 18 12:16:34 2003
@@ -0,0 +1,51 @@
+/*
+ * linux/fs/ext2/xattr_security.c
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext2_fs.h>
+#include "xattr.h"
+
+#define XATTR_NAME_SECURITY "system.security"
+
+static size_t
+ext2_xattr_security_list(char *list, struct inode *inode,
+ const char *name, int name_len)
+{
+ const int size = sizeof(XATTR_NAME_SECURITY);
+
+ if (list)
+ memcpy(list, XATTR_NAME_SECURITY, size);
+ return size;
+}
+
+static int
+ext2_xattr_security_get(struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ext2_xattr_get(inode, EXT2_XATTR_INDEX_SECURITY, name,
+ buffer, size);
+}
+
+static int
+ext2_xattr_security_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY, name,
+ value, size, flags);
+}
+
+struct ext2_xattr_handler ext2_xattr_security_handler = {
+ .prefix = XATTR_NAME_SECURITY,
+ .list = ext2_xattr_security_list,
+ .get = ext2_xattr_security_get,
+ .set = ext2_xattr_security_set,
+};
Index: linux-2.5/fs/ext3/Makefile
diff -u linux-2.5/fs/ext3/Makefile:1.1.1.1 linux-2.5/fs/ext3/Makefile:1.2
--- linux-2.5/fs/ext3/Makefile:1.1.1.1 Wed Mar 12 10:55:31 2003
+++ linux-2.5/fs/ext3/Makefile Wed Mar 26 14:03:26 2003
@@ -14,3 +14,7 @@
ifeq ($(CONFIG_EXT3_FS_POSIX_ACL),y)
ext3-objs += acl.o
endif
+
+ifeq ($(CONFIG_EXT3_FS_SECURITY),y)
+ext3-objs += xattr_security.o
+endif
Index: linux-2.5/fs/ext3/xattr.c
diff -u linux-2.5/fs/ext3/xattr.c:1.1.1.3 linux-2.5/fs/ext3/xattr.c:1.2
--- linux-2.5/fs/ext3/xattr.c:1.1.1.3 Tue Mar 25 09:37:19 2003
+++ linux-2.5/fs/ext3/xattr.c Wed Mar 26 14:03:26 2003
@@ -1141,22 +1141,33 @@
&ext3_xattr_trusted_handler);
if (err)
goto out;
+#ifdef CONFIG_EXT3_FS_SECURITY
+ err = ext3_xattr_register(EXT3_XATTR_INDEX_SECURITY,
+ &ext3_xattr_security_handler);
+ if (err)
+ goto out1;
+#endif
#ifdef CONFIG_EXT3_FS_POSIX_ACL
err = init_ext3_acl();
if (err)
- goto out1;
+ goto out2;
#endif
ext3_xattr_cache = mb_cache_create("ext3_xattr", NULL,
sizeof(struct mb_cache_entry) +
sizeof(struct mb_cache_entry_index), 1, 6);
if (!ext3_xattr_cache) {
err = -ENOMEM;
- goto out2;
+ goto out3;
}
return 0;
-out2:
+out3:
#ifdef CONFIG_EXT3_FS_POSIX_ACL
exit_ext3_acl();
+out2:
+#endif
+#ifdef CONFIG_EXT3_FS_SECURITY
+ ext3_xattr_unregister(EXT3_XATTR_INDEX_SECURITY,
+ &ext3_xattr_security_handler);
out1:
#endif
ext3_xattr_unregister(EXT3_XATTR_INDEX_TRUSTED,
@@ -1175,6 +1186,10 @@
ext3_xattr_cache = NULL;
#ifdef CONFIG_EXT3_FS_POSIX_ACL
exit_ext3_acl();
+#endif
+#ifdef CONFIG_EXT3_FS_SECURITY
+ ext3_xattr_unregister(EXT3_XATTR_INDEX_SECURITY,
+ &ext3_xattr_security_handler);
#endif
ext3_xattr_unregister(EXT3_XATTR_INDEX_TRUSTED,
&ext3_xattr_trusted_handler);
Index: linux-2.5/fs/ext3/xattr.h
diff -u linux-2.5/fs/ext3/xattr.h:1.1.1.1 linux-2.5/fs/ext3/xattr.h:1.2
--- linux-2.5/fs/ext3/xattr.h:1.1.1.1 Wed Mar 12 10:55:32 2003
+++ linux-2.5/fs/ext3/xattr.h Wed Mar 26 14:03:26 2003
@@ -21,6 +21,7 @@
#define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS 2
#define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT 3
#define EXT3_XATTR_INDEX_TRUSTED 4
+#define EXT3_XATTR_INDEX_SECURITY 5
struct ext3_xattr_header {
__u32 h_magic; /* magic number for identification */
@@ -141,3 +142,4 @@
extern struct ext3_xattr_handler ext3_xattr_user_handler;
extern struct ext3_xattr_handler ext3_xattr_trusted_handler;
+extern struct ext3_xattr_handler ext3_xattr_security_handler;
Index: linux-2.5/fs/ext3/xattr_security.c
diff -u /dev/null linux-2.5/fs/ext3/xattr_security.c:1.1
--- /dev/null Fri Apr 18 12:31:13 2003
+++ linux-2.5/fs/ext3/xattr_security.c Wed Mar 26 14:03:26 2003
@@ -0,0 +1,52 @@
+/*
+ * linux/fs/ext3/xattr_security.c
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+
+#define XATTR_NAME_SECURITY "system.security"
+
+static size_t
+ext3_xattr_security_list(char *list, struct inode *inode,
+ const char *name, int name_len)
+{
+ const int size = sizeof(XATTR_NAME_SECURITY);
+
+ if (list)
+ memcpy(list, XATTR_NAME_SECURITY, size);
+ return size;
+}
+
+static int
+ext3_xattr_security_get(struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ext3_xattr_get(inode, EXT3_XATTR_INDEX_SECURITY, name,
+ buffer, size);
+}
+
+static int
+ext3_xattr_security_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return ext3_xattr_set(inode, EXT3_XATTR_INDEX_SECURITY, name,
+ value, size, flags);
+}
+
+struct ext3_xattr_handler ext3_xattr_security_handler = {
+ .prefix = XATTR_NAME_SECURITY,
+ .list = ext3_xattr_security_list,
+ .get = ext3_xattr_security_get,
+ .set = ext3_xattr_security_set,
+};
Index: linux-2.5/include/linux/security.h
diff -u linux-2.5/include/linux/security.h:1.1.1.2 linux-2.5/include/linux/security.h:1.16
--- linux-2.5/include/linux/security.h:1.1.1.2 Wed Mar 19 09:54:58 2003
+++ linux-2.5/include/linux/security.h Fri Apr 18 11:17:19 2003
@@ -361,6 +361,9 @@
* Check permission before setting the extended attributes
* @value identified by @name for @dentry.
* Return 0 if permission is granted.
+ * @inode_post_setxattr:
+ * Update inode security field after successful setxattr operation.
+ * @value identified by @name for @dentry.
* @inode_getxattr:
* Check permission before obtaining the extended attributes
* identified by @name for @dentry.
@@ -1036,6 +1039,8 @@
void (*inode_delete) (struct inode *inode);
int (*inode_setxattr) (struct dentry *dentry, char *name, void *value,
size_t size, int flags);
+ void (*inode_post_setxattr) (struct dentry *dentry, char *name, void *value,
+ size_t size, int flags);
int (*inode_getxattr) (struct dentry *dentry, char *name);
int (*inode_listxattr) (struct dentry *dentry);
int (*inode_removexattr) (struct dentry *dentry, char *name);
@@ -1464,6 +1472,12 @@
return security_ops->inode_setxattr (dentry, name, value, size, flags);
}
+static inline void security_inode_post_setxattr (struct dentry *dentry, char *name,
+ void *value, size_t size, int flags)
+{
+ security_ops->inode_post_setxattr (dentry, name, value, size, flags);
+}
+
static inline int security_inode_getxattr (struct dentry *dentry, char *name)
{
return security_ops->inode_getxattr (dentry, name);
@@ -2063,6 +2087,10 @@
return 0;
}
+static inline void security_inode_post_setxattr (struct dentry *dentry, char *name,
+ void *value, size_t size, int flags)
+{ }
+
static inline int security_inode_getxattr (struct dentry *dentry, char *name)
{
return 0;
Index: linux-2.5/security/dummy.c
diff -u linux-2.5/security/dummy.c:1.1.1.2 linux-2.5/security/dummy.c:1.14
--- linux-2.5/security/dummy.c:1.1.1.2 Wed Mar 19 09:59:17 2003
+++ linux-2.5/security/dummy.c Fri Apr 18 11:17:20 2003
@@ -334,6 +334,11 @@
return 0;
}
+static void dummy_inode_post_setxattr (struct dentry *dentry, char *name, void *value,
+ size_t size, int flags)
+{
+}
+
static int dummy_inode_getxattr (struct dentry *dentry, char *name)
{
return 0;
@@ -803,6 +818,7 @@
set_to_dummy_if_null(ops, inode_getattr);
set_to_dummy_if_null(ops, inode_delete);
set_to_dummy_if_null(ops, inode_setxattr);
+ set_to_dummy_if_null(ops, inode_post_setxattr);
set_to_dummy_if_null(ops, inode_getxattr);
set_to_dummy_if_null(ops, inode_listxattr);
set_to_dummy_if_null(ops, inode_removexattr);
-- Stephen Smalley <sds@epoch.ncsc.mil> National Security Agency- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/