Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/…

…jmorris/linux-security

Pull security layer updates from James Morris:
 "In terms of changes, there's general maintenance to the Smack,
  SELinux, and integrity code.

  The IMA code adds a new kconfig option, IMA_APPRAISE_SIGNED_INIT,
  which allows IMA appraisal to require signatures.  Support for reading
  keys from rootfs before init is call is also added"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
  selinux: Remove security_ops extern
  security: smack: fix out-of-bounds access in smk_parse_smack()
  VFS: refactor vfs_read()
  ima: require signature based appraisal
  integrity: provide a hook to load keys when rootfs is ready
  ima: load x509 certificate from the kernel
  integrity: provide a function to load x509 certificate from the kernel
  integrity: define a new function integrity_read_file()
  Security: smack: replace kzalloc with kmem_cache for inode_smack
  Smack: Lock mode for the floor and hat labels
  ima: added support for new kernel cmdline parameter ima_template_fmt
  ima: allocate field pointers array on demand in template_desc_init_fields()
  ima: don't allocate a copy of template_fmt in template_desc_init_fields()
  ima: display template format in meas. list if template name length is zero
  ima: added error messages to template-related functions
  ima: use atomic bit operations to protect policy update interface
  ima: ignore empty and with whitespaces policy lines
  ima: no need to allocate entry for comment
  ima: report policy load status
  ima: use path names cache
  ...

Documentation/kernel-parameters.txt

@@ -1376,6 +1376,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			Formats: { "ima" | "ima-ng" }
 			Default: "ima-ng"
 
+	ima_template_fmt=
+	                [IMA] Define a custom template format.
+			Format: { "field1|...|fieldN" }
+
 	ima.ahash_minsize= [IMA] Minimum file size for asynchronous hash usage
 			Format: <min_file_size>
 			Set the minimal file size for using asynchronous hash.

Documentation/security/IMA-templates.txt

@@ -27,25 +27,22 @@ Managing templates with these structures is very simple. To support
 a new data type, developers define the field identifier and implement
 two functions, init() and show(), respectively to generate and display
 measurement entries. Defining a new template descriptor requires
-specifying the template format, a string of field identifiers separated
-by the '|' character. While in the current implementation it is possible
-to define new template descriptors only by adding their definition in the
-template specific code (ima_template.c), in a future version it will be
-possible to register a new template on a running kernel by supplying to IMA
-the desired format string. In this version, IMA initializes at boot time
-all defined template descriptors by translating the format into an array
-of template fields structures taken from the set of the supported ones.
+specifying the template format (a string of field identifiers separated
+by the '|' character) through the 'ima_template_fmt' kernel command line
+parameter. At boot time, IMA initializes the chosen template descriptor
+by translating the format into an array of template fields structures taken
+from the set of the supported ones.
 
 After the initialization step, IMA will call ima_alloc_init_template()
 (new function defined within the patches for the new template management
 mechanism) to generate a new measurement entry by using the template
 descriptor chosen through the kernel configuration or through the newly
-introduced 'ima_template=' kernel command line parameter. It is during this
-phase that the advantages of the new architecture are clearly shown:
-the latter function will not contain specific code to handle a given template
-but, instead, it simply calls the init() method of the template fields
-associated to the chosen template descriptor and store the result (pointer
-to allocated data and data length) in the measurement entry structure.
+introduced 'ima_template' and 'ima_template_fmt' kernel command line parameters.
+It is during this phase that the advantages of the new architecture are
+clearly shown: the latter function will not contain specific code to handle
+a given template but, instead, it simply calls the init() method of the template
+fields associated to the chosen template descriptor and store the result
+(pointer to allocated data and data length) in the measurement entry structure.
 
 The same mechanism is employed to display measurements entries.
 The functions ima[_ascii]_measurements_show() retrieve, for each entry,
@@ -86,4 +83,6 @@ currently the following methods are supported:
  - select a template descriptor among those supported in the kernel
    configuration ('ima-ng' is the default choice);
  - specify a template descriptor name from the kernel command line through
-   the 'ima_template=' parameter.
+   the 'ima_template=' parameter;
+ - register a new template descriptor with custom format through the kernel
+   command line parameter 'ima_template_fmt='.

fs/read_write.c

@@ -412,6 +412,23 @@ ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *p
 
 EXPORT_SYMBOL(new_sync_read);
 
+ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
+		   loff_t *pos)
+{
+	ssize_t ret;
+
+	if (file->f_op->read)
+		ret = file->f_op->read(file, buf, count, pos);
+	else if (file->f_op->aio_read)
+		ret = do_sync_read(file, buf, count, pos);
+	else if (file->f_op->read_iter)
+		ret = new_sync_read(file, buf, count, pos);
+	else
+		ret = -EINVAL;
+
+	return ret;
+}
+
 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 {
 	ssize_t ret;
@@ -426,12 +443,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 	ret = rw_verify_area(READ, file, pos, count);
 	if (ret >= 0) {
 		count = ret;
-		if (file->f_op->read)
-			ret = file->f_op->read(file, buf, count, pos);
-		else if (file->f_op->aio_read)
-			ret = do_sync_read(file, buf, count, pos);
-		else
-			ret = new_sync_read(file, buf, count, pos);
+		ret = __vfs_read(file, buf, count, pos);
 		if (ret > 0) {
 			fsnotify_access(file);
 			add_rchar(current, ret);

include/linux/fs.h

@@ -1582,6 +1582,7 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
 			      struct iovec *fast_pointer,
 			      struct iovec **ret_pointer);
 
+extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,

include/linux/integrity.h

@@ -24,6 +24,7 @@ enum integrity_status {
 #ifdef CONFIG_INTEGRITY
 extern struct integrity_iint_cache *integrity_inode_get(struct inode *inode);
 extern void integrity_inode_free(struct inode *inode);
+extern void __init integrity_load_keys(void);
 
 #else
 static inline struct integrity_iint_cache *
@@ -36,5 +37,10 @@ static inline void integrity_inode_free(struct inode *inode)
 {
 	return;
 }
+
+static inline void integrity_load_keys(void)
+{
+}
 #endif /* CONFIG_INTEGRITY */
+
 #endif /* _LINUX_INTEGRITY_H */

init/main.c

@@ -78,6 +78,7 @@
 #include <linux/context_tracking.h>
 #include <linux/random.h>
 #include <linux/list.h>
+#include <linux/integrity.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>
@@ -1031,8 +1032,11 @@ static noinline void __init kernel_init_freeable(void)
 	 * Ok, we have completed the initial bootup, and
 	 * we're essentially up and running. Get rid of the
 	 * initmem segments and start the user-mode stuff..
+	 *
+	 * rootfs is available now, try loading the public keys
+	 * and default modules
 	 */
 
-	/* rootfs is available now, try loading default modules */
+	integrity_load_keys();
 	load_default_modules();
 }

security/integrity/digsig.c

@@ -14,7 +14,7 @@
 
 #include <linux/err.h>
 #include <linux/sched.h>
-#include <linux/rbtree.h>
+#include <linux/slab.h>
 #include <linux/cred.h>
 #include <linux/key-type.h>
 #include <linux/digsig.h>
@@ -63,7 +63,7 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 	return -EOPNOTSUPP;
 }
 
-int integrity_init_keyring(const unsigned int id)
+int __init integrity_init_keyring(const unsigned int id)
 {
 	const struct cred *cred = current_cred();
 	int err = 0;
@@ -84,3 +84,37 @@ int integrity_init_keyring(const unsigned int id)
 	}
 	return err;
 }
+
+int __init integrity_load_x509(const unsigned int id, char *path)
+{
+	key_ref_t key;
+	char *data;
+	int rc;
+
+	if (!keyring[id])
+		return -EINVAL;
+
+	rc = integrity_read_file(path, &data);
+	if (rc < 0)
+		return rc;
+
+	key = key_create_or_update(make_key_ref(keyring[id], 1),
+				   "asymmetric",
+				   NULL,
+				   data,
+				   rc,
+				   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				    KEY_USR_VIEW | KEY_USR_READ),
+				   KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_TRUSTED);
+	if (IS_ERR(key)) {
+		rc = PTR_ERR(key);
+		pr_err("Problem loading X.509 certificate (%d): %s\n",
+		       rc, path);
+	} else {
+		pr_notice("Loaded X.509 cert '%s': %s\n",
+			  key_ref_to_ptr(key)->description, path);
+		key_ref_put(key);
+	}
+	kfree(data);
+	return 0;
+}

security/integrity/evm/evm_main.c

@@ -162,9 +162,14 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
 					(const char *)xattr_data, xattr_len,
 					calc.digest, sizeof(calc.digest));
 		if (!rc) {
-			/* we probably want to replace rsa with hmac here */
-			evm_update_evmxattr(dentry, xattr_name, xattr_value,
-				   xattr_value_len);
+			/* Replace RSA with HMAC if not mounted readonly and
+			 * not immutable
+			 */
+			if (!IS_RDONLY(dentry->d_inode) &&
+			    !IS_IMMUTABLE(dentry->d_inode))
+				evm_update_evmxattr(dentry, xattr_name,
+						    xattr_value,
+						    xattr_value_len);
 		}
 		break;
 	default:

security/integrity/iint.c

@@ -19,14 +19,14 @@
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/rbtree.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
 #include "integrity.h"
 
 static struct rb_root integrity_iint_tree = RB_ROOT;
 static DEFINE_RWLOCK(integrity_iint_lock);
 static struct kmem_cache *iint_cache __read_mostly;
 
-int iint_initialized;
-
 /*
  * __integrity_iint_find - return the iint associated with an inode
  */
@@ -166,7 +166,89 @@ static int __init integrity_iintcache_init(void)
 	iint_cache =
 	    kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
 			      0, SLAB_PANIC, init_once);
-	iint_initialized = 1;
 	return 0;
 }
 security_initcall(integrity_iintcache_init);
+
+
+/*
+ * integrity_kernel_read - read data from the file
+ *
+ * This is a function for reading file content instead of kernel_read().
+ * It does not perform locking checks to ensure it cannot be blocked.
+ * It does not perform security checks because it is irrelevant for IMA.
+ *
+ */
+int integrity_kernel_read(struct file *file, loff_t offset,
+			  char *addr, unsigned long count)
+{
+	mm_segment_t old_fs;
+	char __user *buf = (char __user *)addr;
+	ssize_t ret;
+
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	ret = __vfs_read(file, buf, count, &offset);
+	set_fs(old_fs);
+
+	return ret;
+}
+
+/*
+ * integrity_read_file - read entire file content into the buffer
+ *
+ * This is function opens a file, allocates the buffer of required
+ * size, read entire file content to the buffer and closes the file
+ *
+ * It is used only by init code.
+ *
+ */
+int __init integrity_read_file(const char *path, char **data)
+{
+	struct file *file;
+	loff_t size;
+	char *buf;
+	int rc = -EINVAL;
+
+	file = filp_open(path, O_RDONLY, 0);
+	if (IS_ERR(file)) {
+		rc = PTR_ERR(file);
+		pr_err("Unable to open file: %s (%d)", path, rc);
+		return rc;
+	}
+
+	size = i_size_read(file_inode(file));
+	if (size <= 0)
+		goto out;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	rc = integrity_kernel_read(file, 0, buf, size);
+	if (rc < 0)
+		kfree(buf);
+	else if (rc != size)
+		rc = -EIO;
+	else
+		*data = buf;
+out:
+	fput(file);
+	return rc;
+}
+
+/*
+ * integrity_load_keys - load integrity keys hook
+ *
+ * Hooks is called from init/main.c:kernel_init_freeable()
+ * when rootfs is ready
+ */
+void __init integrity_load_keys(void)
+{
+	ima_load_x509();
+}

security/integrity/ima/Kconfig

@@ -131,3 +131,28 @@ config IMA_TRUSTED_KEYRING
 	help
 	   This option requires that all keys added to the .ima
 	   keyring be signed by a key on the system trusted keyring.
+
+config IMA_LOAD_X509
+	bool "Load X509 certificate onto the '.ima' trusted keyring"
+	depends on IMA_TRUSTED_KEYRING
+	default n
+	help
+	   File signature verification is based on the public keys
+	   loaded on the .ima trusted keyring. These public keys are
+	   X509 certificates signed by a trusted key on the
+	   .system keyring.  This option enables X509 certificate
+	   loading from the kernel onto the '.ima' trusted keyring.
+
+config IMA_X509_PATH
+	string "IMA X509 certificate path"
+	depends on IMA_LOAD_X509
+	default "/etc/keys/x509_ima.der"
+	help
+	   This option defines IMA X509 certificate path.
+
+config IMA_APPRAISE_SIGNED_INIT
+	bool "Require signed user-space initialization"
+	depends on IMA_LOAD_X509
+	default n
+	help
+	   This option requires user-space init to be signed.

security/integrity/ima/ima_api.c

@@ -173,8 +173,7 @@ int ima_get_action(struct inode *inode, int mask, int function)
 {
 	int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE;
 
-	if (!ima_appraise)
-		flags &= ~IMA_APPRAISE;
+	flags &= ima_policy_flag;
 
 	return ima_match_policy(inode, function, mask, flags);
 }
@@ -325,11 +324,11 @@ const char *ima_d_path(struct path *path, char **pathbuf)
 {
 	char *pathname = NULL;
 
-	*pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
+	*pathbuf = __getname();
 	if (*pathbuf) {
 		pathname = d_absolute_path(path, *pathbuf, PATH_MAX);
 		if (IS_ERR(pathname)) {
-			kfree(*pathbuf);
+			__putname(*pathbuf);
 			*pathbuf = NULL;
 			pathname = NULL;
 		}