[apparmor] [PATCH 20/27] apparmor: Add interface files for profiles and namespaces

John Johansen john.johansen at canonical.com
Wed Nov 21 04:40:00 UTC 2012


Add basic interface files to access namespace and profile information.
The interface files are created when a profile is loaded and removed
when the profile or namespace is removed.

Signed-off-by: John Johansen <john.johansen at canonical.com>
---
 security/apparmor/apparmorfs.c         |  281 ++++++++++++++++++++++++++++++--
 security/apparmor/audit.c              |    6 +
 security/apparmor/include/apparmorfs.h |   24 +++
 security/apparmor/include/audit.h      |    2 +
 security/apparmor/include/policy.h     |   11 ++
 security/apparmor/policy.c             |   51 +++++-
 6 files changed, 351 insertions(+), 24 deletions(-)

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index b73e59b..7919735 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -12,6 +12,7 @@
  * License.
  */
 
+#include <linux/ctype.h>
 #include <linux/security.h>
 #include <linux/vmalloc.h>
 #include <linux/module.h>
@@ -28,6 +29,49 @@
 #include "include/resource.h"
 
 /**
+ * aa_mangle_name - mangle a profile name to std profile layout form
+ * @name: profile name to mangle  (NOT NULL)
+ * @target: buffer to store mangled name, same length as @name (MAYBE NULL)
+ *
+ * Returns: length of mangled name
+ */
+static int mangle_name(char *name, char *target)
+{
+	char *t = target;
+
+	while (*name == '/' || *name == '.')
+		name++;
+
+	if (target) {
+		for (; *name; name++) {
+			if (strchr("\"\'(){}[]", *name))
+				continue;
+			else if (*name == '/')
+				*(t)++ = '.';
+			else if (isspace(*name))
+				*(t)++ = '_';
+			else if (strchr("*?^$\\", *name))
+				*(t)++ = 'X';
+			else if (isgraph(*name))
+				*(t)++ = *name;
+		}
+
+		*t = 0;
+	} else {
+		int len = 0;
+		for (; *name; name++) {
+			if (strchr("\"\'(){}[]", *name))
+				continue;
+			len++;
+		}
+
+		return len;
+	}
+
+	return t - target;
+}
+
+/**
  * aa_simple_write_to_buffer - common routine for getting policy from user
  * @op: operation doing the user buffer copy
  * @userbuf: user buffer to copy data from  (NOT NULL)
@@ -182,8 +226,206 @@ const struct file_operations aa_fs_seq_file_ops = {
 	.release	= single_release,
 };
 
-/** Base file system setup **/
+static int aa_fs_seq_string_show(struct seq_file *seq, void *v)
+{
+	char *string = seq->private;
+
+	if (string)
+		seq_printf(seq, "%s\n", string);
+
+	return 0;
+}
+
+static int aa_fs_seq_string_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, aa_fs_seq_string_show, inode->i_private);
+}
+
+const struct file_operations aa_fs_seq_string_fops = {
+	.owner		= THIS_MODULE,
+	.open		= aa_fs_seq_string_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int aa_fs_seq_mode_show(struct seq_file *seq, void *v)
+{
+	enum profile_mode *mode = seq->private;
+
+	seq_printf(seq, "%s\n", aa_profile_mode_names[*mode]);
+
+	return 0;
+}
+
+static int aa_fs_seq_mode_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, aa_fs_seq_mode_show, inode->i_private);
+}
+
+const struct file_operations aa_fs_seq_mode_fops = {
+	.owner		= THIS_MODULE,
+	.open		= aa_fs_seq_mode_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+/** fns to setup dynamic per profile/namespace files **/
+void __aa_fs_profile_rmdir(struct aa_profile *profile)
+{
+	struct aa_profile *child;
+	int i;
+
+	if (!profile)
+		return;
+
+	list_for_each_entry(child, &profile->base.profiles, base.list)
+		__aa_fs_profile_rmdir(child);
+
+	for (i = AAFS_PROF_SIZE - 1; i >= 0; --i) {
+		securityfs_remove(profile->dents[i]);
+		profile->dents[i] = NULL;
+	}
+}
+
+/* requires lock be held */
+int __aa_fs_profile_mkdir(struct aa_profile *profile, struct dentry *parent)
+{
+	struct aa_profile *child;
+	struct dentry *dent = NULL, *dir;
+	int error;
+
+	if (!parent) {
+		dent = profile->parent->dents[AAFS_PROF_DIR];
+		/* adding to parent that previously didn't have children */
+		dent = securityfs_create_dir("profiles", dent);
+		if (!dent)
+			goto fail;
+		profile->parent->dents[AAFS_PROF_PROFS] = parent = dent;
+	}
+
+	if (!profile->dirname) {
+		int len, id_len;
+		len = mangle_name(profile->base.name, NULL);
+		id_len = snprintf(NULL, 0, ".%ld", profile->ns->uniq_id);
+
+		profile->dirname = kmalloc(len + id_len + 1, GFP_KERNEL);
+		if (!profile->dirname)
+			goto fail;
 
+		mangle_name(profile->base.name, profile->dirname);
+		sprintf(profile->dirname + len, ".%ld", profile->ns->uniq_id++);
+	}
+
+	dent = securityfs_create_dir(profile->dirname, parent);
+	if (IS_ERR(dent))
+		goto fail;
+	profile->dents[AAFS_PROF_DIR] = dir = dent;
+
+	dent = securityfs_create_file("name", S_IFREG | 0444, dir,
+				      profile->base.name,
+				      &aa_fs_seq_string_fops);
+	if (IS_ERR(dent))
+		goto fail;
+	profile->dents[AAFS_PROF_NAME] = dent;
+
+	dent = securityfs_create_file("mode", S_IFREG | 0444, dir,
+				      &profile->mode, &aa_fs_seq_mode_fops);
+	if (IS_ERR(dent))
+		goto fail;
+	profile->dents[AAFS_PROF_MODE] = dent;
+
+	list_for_each_entry(child, &profile->base.profiles, base.list) {
+		error = __aa_fs_profile_mkdir(child, profile->dents[AAFS_PROF_PROFS]);
+		if (error)
+			goto fail2;
+	}
+
+	return 0;
+
+fail:
+	error = PTR_ERR(dent);
+
+fail2:
+	__aa_fs_profile_rmdir(profile);
+
+	return error;
+}
+
+void __aa_fs_namespace_rmdir(struct aa_namespace *ns)
+{
+	struct aa_namespace *sub;
+	struct aa_profile *child;
+	int i;
+
+	if (!ns)
+		return;
+
+	list_for_each_entry(child, &ns->base.profiles, base.list)
+		__aa_fs_profile_rmdir(child);
+
+	list_for_each_entry(sub, &ns->sub_ns, base.list)
+		__aa_fs_namespace_rmdir(sub);
+
+	for (i = AAFS_NS_SIZE - 1; i >= 0 ; --i) {
+		securityfs_remove(ns->dents[i]);
+		ns->dents[i] = NULL;
+	}
+}
+
+int __aa_fs_namespace_mkdir(struct aa_namespace *ns, struct dentry *parent,
+			    const char *name)
+{
+	struct aa_namespace *sub;
+	struct aa_profile *child;
+	struct dentry *dent, *dir;
+	int error;
+
+	if (!name)
+		name = ns->base.name;
+
+	dent = securityfs_create_dir(name, parent);
+	if (IS_ERR(dent))
+		goto fail;
+	ns->dents[AAFS_NS_DIR] = dir = dent;
+
+	dent = securityfs_create_dir("profiles", dir);
+	if (IS_ERR(dent))
+		goto fail;
+	ns->dents[AAFS_NS_PROFS] = dent;
+
+	dent = securityfs_create_dir("namespaces", dir);
+	if (IS_ERR(dent))
+		goto fail;
+	ns->dents[AAFS_NS_NS] = dent;
+
+	list_for_each_entry(child, &ns->base.profiles, base.list) {
+		error = __aa_fs_profile_mkdir(child, ns->dents[AAFS_NS_PROFS]);
+		if (error)
+			goto fail2;
+	}
+
+	list_for_each_entry(sub, &ns->sub_ns, base.list) {
+		error = __aa_fs_namespace_mkdir(sub, ns->dents[AAFS_NS_NS],
+						NULL);
+		if (error)
+			goto fail2;
+	}
+
+	return 0;
+
+fail:
+	error = PTR_ERR(dent);
+
+fail2:
+	__aa_fs_namespace_rmdir(ns);
+
+	return error;
+}
+
+
+/** Base file system setup **/
 static struct aa_fs_entry aa_fs_entry_file[] = {
 	AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \
 				  "link lock"),
@@ -221,8 +463,10 @@ static struct aa_fs_entry aa_fs_entry_apparmor[] = {
 	{ }
 };
 
-static struct aa_fs_entry aa_fs_entry =
-	AA_FS_DIR("apparmor", aa_fs_entry_apparmor);
+static struct aa_fs_entry aa_fs_entry[] = {
+	AA_FS_DIR("apparmor", aa_fs_entry_apparmor),
+	{ }
+};
 
 /**
  * aafs_create_file - create a file entry in the apparmor securityfs
@@ -247,6 +491,7 @@ static int __init aafs_create_file(struct aa_fs_entry *fs_file,
 	return error;
 }
 
+static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir);
 /**
  * aafs_create_dir - recursively create a directory entry in the securityfs
  * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
@@ -257,17 +502,16 @@ static int __init aafs_create_file(struct aa_fs_entry *fs_file,
 static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
 				  struct dentry *parent)
 {
-	int error;
 	struct aa_fs_entry *fs_file;
+	struct dentry *dir;
+	int error;
 
-	fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
-	if (IS_ERR(fs_dir->dentry)) {
-		error = PTR_ERR(fs_dir->dentry);
-		fs_dir->dentry = NULL;
-		goto failed;
-	}
+	dir = securityfs_create_dir(fs_dir->name, parent);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+	fs_dir->dentry = dir;
 
-	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
+	for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) {
 		if (fs_file->v_type == AA_FS_TYPE_DIR)
 			error = aafs_create_dir(fs_file, fs_dir->dentry);
 		else
@@ -279,6 +523,8 @@ static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
 	return 0;
 
 failed:
+	aafs_remove_dir(fs_dir);
+
 	return error;
 }
 
@@ -303,7 +549,7 @@ static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
 {
 	struct aa_fs_entry *fs_file;
 
-	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
+	for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) {
 		if (fs_file->v_type == AA_FS_TYPE_DIR)
 			aafs_remove_dir(fs_file);
 		else
@@ -320,7 +566,7 @@ static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
  */
 void __init aa_destroy_aafs(void)
 {
-	aafs_remove_dir(&aa_fs_entry);
+	aafs_remove_dir(aa_fs_entry);
 }
 
 /**
@@ -337,13 +583,18 @@ static int __init aa_create_aafs(void)
 	if (!apparmor_initialized)
 		return 0;
 
-	if (aa_fs_entry.dentry) {
+	if (aa_fs_entry[0].dentry) {
 		AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
 		return -EEXIST;
 	}
 
 	/* Populate fs tree. */
-	error = aafs_create_dir(&aa_fs_entry, NULL);
+	error = aafs_create_dir(aa_fs_entry, NULL);
+	if (error)
+		goto error;
+
+	error = __aa_fs_namespace_mkdir(root_ns, aa_fs_entry[0].dentry,
+					"policy");
 	if (error)
 		goto error;
 
diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
index 031d2d9..3f221c7 100644
--- a/security/apparmor/audit.c
+++ b/security/apparmor/audit.c
@@ -73,6 +73,12 @@ const char *const op_table[] = {
 	"profile_remove"
 };
 
+const char *const aa_profile_mode_names[] = {
+	"enforce",
+	"complain",
+	"kill"
+};
+
 const char *const audit_mode_names[] = {
 	"normal",
 	"quiet_denied",
diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
index 7ea4769..1ab7efd 100644
--- a/security/apparmor/include/apparmorfs.h
+++ b/security/apparmor/include/apparmorfs.h
@@ -61,4 +61,28 @@ extern const struct file_operations aa_fs_seq_file_ops;
 
 extern void __init aa_destroy_aafs(void);
 
+struct aa_profile;
+struct aa_namespace;
+
+enum aafs_ns_type {
+	AAFS_NS_DIR,
+	AAFS_NS_PROFS,
+	AAFS_NS_NS,
+	AAFS_NS_SIZE,
+};
+
+enum aafs_prof_type {
+	AAFS_PROF_DIR,
+	AAFS_PROF_PROFS,
+	AAFS_PROF_NAME,
+	AAFS_PROF_MODE,
+	AAFS_PROF_SIZE,
+};
+
+void __aa_fs_profile_rmdir(struct aa_profile *profile);
+int __aa_fs_profile_mkdir(struct aa_profile *profile, struct dentry *parent);
+void __aa_fs_namespace_rmdir(struct aa_namespace *ns);
+int __aa_fs_namespace_mkdir(struct aa_namespace *ns, struct dentry *parent,
+			    const char *name);
+
 #endif /* __AA_APPARMORFS_H */
diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h
index 69d8cae..6539ab3 100644
--- a/security/apparmor/include/audit.h
+++ b/security/apparmor/include/audit.h
@@ -28,6 +28,8 @@ struct aa_profile;
 extern const char *const audit_mode_names[];
 #define AUDIT_MAX_INDEX 5
 
+extern const char *const aa_profile_mode_names[];
+
 enum audit_mode {
 	AUDIT_NORMAL,		/* follow normal auditing of accesses */
 	AUDIT_QUIET_DENIED,	/* quiet all denied access messages */
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index 0d16d91..07fc7b0 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -108,6 +108,8 @@ struct aa_ns_acct {
  * @acct: accounting for the namespace
  * @unconfined: special unconfined profile for the namespace
  * @sub_ns: list of namespaces under the current namespace.
+ * @uniq_id: a unique id count for the profiles in the namespace
+ * @dents: dentries for the namespaces file entries in apparmorfs
  *
  * An aa_namespace defines the set profiles that are searched to determine
  * which profile to attach to a task.  Profiles can not be shared between
@@ -132,6 +134,9 @@ struct aa_namespace {
 	struct list_head sub_ns;
 
 	atomic_t uniq_null;
+	long uniq_id;
+
+	struct dentry *dents[AAFS_NS_SIZE];
 };
 
 /* struct aa_policydb - match engine for a policy
@@ -163,6 +168,9 @@ struct aa_policydb {
  * @caps: capabilities for the profile
  * @rlimits: rlimits for the profile
  *
+ * @dents: dentries for the profiles file entries in apparmorfs
+ * @dirname: name of the profile dir in apparmorfs
+ *
  * The AppArmor profile contains the basic confinement data.  Each profile
  * has a name, and exists in a namespace.  The @name and @exec_match are
  * used to determine profile attachment against unconfined tasks.  All other
@@ -198,6 +206,9 @@ struct aa_profile {
 	struct aa_file_rules file;
 	struct aa_caps caps;
 	struct aa_rlimit rlimits;
+
+	char *dirname;
+	struct dentry *dents[AAFS_PROF_SIZE];
 };
 
 extern struct aa_namespace *root_ns;
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 4d3f8ba..4297f1d 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -388,7 +388,7 @@ struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
  */
 static struct aa_namespace *aa_prepare_namespace(const char *name)
 {
-	struct aa_namespace *ns, *root;
+	struct aa_namespace *ns, *new_ns = NULL, *root;
 
 	root = aa_current_profile()->ns;
 
@@ -405,11 +405,23 @@ static struct aa_namespace *aa_prepare_namespace(const char *name)
 	/* released by caller */
 	ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
 	if (!ns)
-		ns = alloc_namespace(root->base.hname, name);
+		new_ns = ns = alloc_namespace(root->base.hname, name);
 
 	if (ns) {
 		/* add parent ref */
 		ns->parent = aa_get_namespace(root);
+
+		if (new_ns && __aa_fs_namespace_mkdir(new_ns,
+						     root->dents[AAFS_NS_PROFS],
+						      NULL)) {
+			free_namespace(new_ns);
+			AA_ERROR("Added namespace %s but failed to "
+				 "add interface files.\n",
+				 new_ns->base.name);
+			ns = NULL;
+			goto out;
+		}
+
 		list_add_rcu(&ns->base.list, &root->sub_ns);
 		/* add list ref */
 		aa_get_namespace(ns);
@@ -670,6 +682,7 @@ static void free_profile(struct aa_profile *profile)
 	aa_free_cap_rules(&profile->caps);
 	aa_free_rlimit_rules(&profile->rlimits);
 
+	kzfree(profile->dirname);
 	aa_put_dfa(profile->xmatch);
 	aa_put_dfa(profile->policy.dfa);
 
@@ -1013,11 +1026,11 @@ bool aa_may_manage_policy(int op)
  * @ns - namespace the lookup occurs in
  * @new - profile to lookup who it is replacing
  * @noreplace - true if not replacing an existing profile
- * @old - Returns: pointer to profile to replace (NO REFCOUNT)
- * @rename - Returns: pointer to profile to rename (NO REFCOUNT)
+ * @old - Returns: pointer to profile to replace (ref counted)
+ * @rename - Returns: pointer to profile to rename (ref counted)
  * @info - Returns: info string on why lookup failed
  *
- * Returns: policy (no ref) profile is in on success else ptr error
+ * Returns: policy (no ref count) profile is in on success else ptr error
  */
 static struct aa_policy *__lookup_replace(struct aa_namespace *ns,
 					  struct aa_profile *new,
@@ -1108,10 +1121,9 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
 		policy = __lookup_replace(ns, new, noreplace, NULL, NULL,
 					  &info);
 		if (IS_ERR(policy)) {
-			mutex_unlock(&ns->lock);
 			error = PTR_ERR(policy);
 			name = new->base.hname;
-			goto fail;
+			goto fail_lock;
 		}
 		/* released when @new is freed */
 		new->ns = aa_get_namespace(ns);
@@ -1120,6 +1132,17 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
 			new->parent = aa_get_profile((struct aa_profile *) policy);
 	}
 
+	list_for_each_entry(new, &lh, base.list) {
+		/* make new profiles available for introspection */
+		error = __aa_fs_profile_mkdir(new,
+			new->parent ? new->parent->dents[AAFS_PROF_PROFS] :
+				      new->ns->dents[AAFS_NS_PROFS]);
+		if (error) {
+			info = "failed to create ";
+			goto fail_lock;
+		}
+	}
+
 	/* do actual replacement */
 	list_for_each_entry_safe(new, tmp, &lh, base.list) {
 		struct aa_profile *old, *rename;
@@ -1132,10 +1155,14 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
 
 		audit_policy(op, GFP_ATOMIC, new->base.name, NULL, error);
 
-		if (rename)
+		if (rename) {
 			__replace_profile(rename, new);
-		if (old)
+			__aa_fs_profile_rmdir(rename);
+		}
+		if (old) {
 			__replace_profile(old, new);
+			__aa_fs_profile_rmdir(old);
+		}
 		if (!(old || rename))
 			__list_add_profile(&policy->profiles, new);
 
@@ -1143,6 +1170,7 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
 		aa_put_profile(old);
 		aa_put_profile(new);
 	}
+
 	mutex_unlock(&ns->lock);
 
 out:
@@ -1152,6 +1180,9 @@ out:
 		return error;
 	return size;
 
+fail_lock:
+	mutex_unlock(&ns->lock);
+
 fail:
 	error = audit_policy(op, GFP_KERNEL, name, info, error);
 
@@ -1211,6 +1242,7 @@ ssize_t aa_remove_profiles(char *fqname, size_t size)
 		/* remove namespace - can only happen if fqname[0] == ':' */
 		mutex_lock(&ns->parent->lock);
 		__remove_namespace(ns);
+		__aa_fs_namespace_rmdir(ns);
 		mutex_unlock(&ns->parent->lock);
 	} else {
 		/* remove profile */
@@ -1223,6 +1255,7 @@ ssize_t aa_remove_profiles(char *fqname, size_t size)
 		}
 		name = profile->base.hname;
 		__remove_profile(profile);
+		__aa_fs_profile_rmdir(profile);
 		mutex_unlock(&ns->lock);
 	}
 
-- 
1.7.10.4




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