Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1122 insertions, 0 deletions

diff --git a/security/tomoyo/condition.c b/security/tomoyo/condition.c
new file mode 100644
index 000000000..f8bcc083b
--- /dev/null
+++ b/security/tomoyo/condition.c
@@ -0,0 +1,1122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * security/tomoyo/condition.c
+ *
+ * Copyright (C) 2005-2011  NTT DATA CORPORATION
+ */
+
+#include "common.h"
+#include <linux/slab.h>
+
+/* List of "struct tomoyo_condition". */
+LIST_HEAD(tomoyo_condition_list);
+
+/**
+ * tomoyo_argv - Check argv[] in "struct linux_binbrm".
+ *
+ * @index:   Index number of @arg_ptr.
+ * @arg_ptr: Contents of argv[@index].
+ * @argc:    Length of @argv.
+ * @argv:    Pointer to "struct tomoyo_argv".
+ * @checked: Set to true if @argv[@index] was found.
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_argv(const unsigned int index, const char *arg_ptr,
+			const int argc, const struct tomoyo_argv *argv,
+			u8 *checked)
+{
+	int i;
+	struct tomoyo_path_info arg;
+
+	arg.name = arg_ptr;
+	for (i = 0; i < argc; argv++, checked++, i++) {
+		bool result;
+
+		if (index != argv->index)
+			continue;
+		*checked = 1;
+		tomoyo_fill_path_info(&arg);
+		result = tomoyo_path_matches_pattern(&arg, argv->value);
+		if (argv->is_not)
+			result = !result;
+		if (!result)
+			return false;
+	}
+	return true;
+}
+
+/**
+ * tomoyo_envp - Check envp[] in "struct linux_binbrm".
+ *
+ * @env_name:  The name of environment variable.
+ * @env_value: The value of environment variable.
+ * @envc:      Length of @envp.
+ * @envp:      Pointer to "struct tomoyo_envp".
+ * @checked:   Set to true if @envp[@env_name] was found.
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_envp(const char *env_name, const char *env_value,
+			const int envc, const struct tomoyo_envp *envp,
+			u8 *checked)
+{
+	int i;
+	struct tomoyo_path_info name;
+	struct tomoyo_path_info value;
+
+	name.name = env_name;
+	tomoyo_fill_path_info(&name);
+	value.name = env_value;
+	tomoyo_fill_path_info(&value);
+	for (i = 0; i < envc; envp++, checked++, i++) {
+		bool result;
+
+		if (!tomoyo_path_matches_pattern(&name, envp->name))
+			continue;
+		*checked = 1;
+		if (envp->value) {
+			result = tomoyo_path_matches_pattern(&value,
+							     envp->value);
+			if (envp->is_not)
+				result = !result;
+		} else {
+			result = true;
+			if (!envp->is_not)
+				result = !result;
+		}
+		if (!result)
+			return false;
+	}
+	return true;
+}
+
+/**
+ * tomoyo_scan_bprm - Scan "struct linux_binprm".
+ *
+ * @ee:   Pointer to "struct tomoyo_execve".
+ * @argc: Length of @argc.
+ * @argv: Pointer to "struct tomoyo_argv".
+ * @envc: Length of @envp.
+ * @envp: Pointer to "struct tomoyo_envp".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_scan_bprm(struct tomoyo_execve *ee,
+			     const u16 argc, const struct tomoyo_argv *argv,
+			     const u16 envc, const struct tomoyo_envp *envp)
+{
+	struct linux_binprm *bprm = ee->bprm;
+	struct tomoyo_page_dump *dump = &ee->dump;
+	char *arg_ptr = ee->tmp;
+	int arg_len = 0;
+	unsigned long pos = bprm->p;
+	int offset = pos % PAGE_SIZE;
+	int argv_count = bprm->argc;
+	int envp_count = bprm->envc;
+	bool result = true;
+	u8 local_checked[32];
+	u8 *checked;
+
+	if (argc + envc <= sizeof(local_checked)) {
+		checked = local_checked;
+		memset(local_checked, 0, sizeof(local_checked));
+	} else {
+		checked = kzalloc(argc + envc, GFP_NOFS);
+		if (!checked)
+			return false;
+	}
+	while (argv_count || envp_count) {
+		if (!tomoyo_dump_page(bprm, pos, dump)) {
+			result = false;
+			goto out;
+		}
+		pos += PAGE_SIZE - offset;
+		while (offset < PAGE_SIZE) {
+			/* Read. */
+			const char *kaddr = dump->data;
+			const unsigned char c = kaddr[offset++];
+
+			if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
+				if (c == '\\') {
+					arg_ptr[arg_len++] = '\\';
+					arg_ptr[arg_len++] = '\\';
+				} else if (c > ' ' && c < 127) {
+					arg_ptr[arg_len++] = c;
+				} else {
+					arg_ptr[arg_len++] = '\\';
+					arg_ptr[arg_len++] = (c >> 6) + '0';
+					arg_ptr[arg_len++] =
+						((c >> 3) & 7) + '0';
+					arg_ptr[arg_len++] = (c & 7) + '0';
+				}
+			} else {
+				arg_ptr[arg_len] = '\0';
+			}
+			if (c)
+				continue;
+			/* Check. */
+			if (argv_count) {
+				if (!tomoyo_argv(bprm->argc - argv_count,
+						 arg_ptr, argc, argv,
+						 checked)) {
+					result = false;
+					break;
+				}
+				argv_count--;
+			} else if (envp_count) {
+				char *cp = strchr(arg_ptr, '=');
+
+				if (cp) {
+					*cp = '\0';
+					if (!tomoyo_envp(arg_ptr, cp + 1,
+							 envc, envp,
+							 checked + argc)) {
+						result = false;
+						break;
+					}
+				}
+				envp_count--;
+			} else {
+				break;
+			}
+			arg_len = 0;
+		}
+		offset = 0;
+		if (!result)
+			break;
+	}
+out:
+	if (result) {
+		int i;
+
+		/* Check not-yet-checked entries. */
+		for (i = 0; i < argc; i++) {
+			if (checked[i])
+				continue;
+			/*
+			 * Return true only if all unchecked indexes in
+			 * bprm->argv[] are not matched.
+			 */
+			if (argv[i].is_not)
+				continue;
+			result = false;
+			break;
+		}
+		for (i = 0; i < envc; envp++, i++) {
+			if (checked[argc + i])
+				continue;
+			/*
+			 * Return true only if all unchecked environ variables
+			 * in bprm->envp[] are either undefined or not matched.
+			 */
+			if ((!envp->value && !envp->is_not) ||
+			    (envp->value && envp->is_not))
+				continue;
+			result = false;
+			break;
+		}
+	}
+	if (checked != local_checked)
+		kfree(checked);
+	return result;
+}
+
+/**
+ * tomoyo_scan_exec_realpath - Check "exec.realpath" parameter of "struct tomoyo_condition".
+ *
+ * @file:  Pointer to "struct file".
+ * @ptr:   Pointer to "struct tomoyo_name_union".
+ * @match: True if "exec.realpath=", false if "exec.realpath!=".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_scan_exec_realpath(struct file *file,
+				      const struct tomoyo_name_union *ptr,
+				      const bool match)
+{
+	bool result;
+	struct tomoyo_path_info exe;
+
+	if (!file)
+		return false;
+	exe.name = tomoyo_realpath_from_path(&file->f_path);
+	if (!exe.name)
+		return false;
+	tomoyo_fill_path_info(&exe);
+	result = tomoyo_compare_name_union(&exe, ptr);
+	kfree(exe.name);
+	return result == match;
+}
+
+/**
+ * tomoyo_get_dqword - tomoyo_get_name() for a quoted string.
+ *
+ * @start: String to save.
+ *
+ * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
+ */
+static const struct tomoyo_path_info *tomoyo_get_dqword(char *start)
+{
+	char *cp = start + strlen(start) - 1;
+
+	if (cp == start || *start++ != '"' || *cp != '"')
+		return NULL;
+	*cp = '\0';
+	if (*start && !tomoyo_correct_word(start))
+		return NULL;
+	return tomoyo_get_name(start);
+}
+
+/**
+ * tomoyo_parse_name_union_quoted - Parse a quoted word.
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ * @ptr:   Pointer to "struct tomoyo_name_union".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_parse_name_union_quoted(struct tomoyo_acl_param *param,
+					   struct tomoyo_name_union *ptr)
+{
+	char *filename = param->data;
+
+	if (*filename == '@')
+		return tomoyo_parse_name_union(param, ptr);
+	ptr->filename = tomoyo_get_dqword(filename);
+	return ptr->filename != NULL;
+}
+
+/**
+ * tomoyo_parse_argv - Parse an argv[] condition part.
+ *
+ * @left:  Lefthand value.
+ * @right: Righthand value.
+ * @argv:  Pointer to "struct tomoyo_argv".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_parse_argv(char *left, char *right,
+			      struct tomoyo_argv *argv)
+{
+	if (tomoyo_parse_ulong(&argv->index, &left) !=
+	    TOMOYO_VALUE_TYPE_DECIMAL || *left++ != ']' || *left)
+		return false;
+	argv->value = tomoyo_get_dqword(right);
+	return argv->value != NULL;
+}
+
+/**
+ * tomoyo_parse_envp - Parse an envp[] condition part.
+ *
+ * @left:  Lefthand value.
+ * @right: Righthand value.
+ * @envp:  Pointer to "struct tomoyo_envp".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_parse_envp(char *left, char *right,
+			      struct tomoyo_envp *envp)
+{
+	const struct tomoyo_path_info *name;
+	const struct tomoyo_path_info *value;
+	char *cp = left + strlen(left) - 1;
+
+	if (*cp-- != ']' || *cp != '"')
+		goto out;
+	*cp = '\0';
+	if (!tomoyo_correct_word(left))
+		goto out;
+	name = tomoyo_get_name(left);
+	if (!name)
+		goto out;
+	if (!strcmp(right, "NULL")) {
+		value = NULL;
+	} else {
+		value = tomoyo_get_dqword(right);
+		if (!value) {
+			tomoyo_put_name(name);
+			goto out;
+		}
+	}
+	envp->name = name;
+	envp->value = value;
+	return true;
+out:
+	return false;
+}
+
+/**
+ * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
+ *
+ * @a: Pointer to "struct tomoyo_condition".
+ * @b: Pointer to "struct tomoyo_condition".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
+					 const struct tomoyo_condition *b)
+{
+	return a->size == b->size && a->condc == b->condc &&
+		a->numbers_count == b->numbers_count &&
+		a->names_count == b->names_count &&
+		a->argc == b->argc && a->envc == b->envc &&
+		a->grant_log == b->grant_log && a->transit == b->transit &&
+		!memcmp(a + 1, b + 1, a->size - sizeof(*a));
+}
+
+/**
+ * tomoyo_condition_type - Get condition type.
+ *
+ * @word: Keyword string.
+ *
+ * Returns one of values in "enum tomoyo_conditions_index" on success,
+ * TOMOYO_MAX_CONDITION_KEYWORD otherwise.
+ */
+static u8 tomoyo_condition_type(const char *word)
+{
+	u8 i;
+
+	for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
+		if (!strcmp(word, tomoyo_condition_keyword[i]))
+			break;
+	}
+	return i;
+}
+
+/* Define this to enable debug mode. */
+/* #define DEBUG_CONDITION */
+
+#ifdef DEBUG_CONDITION
+#define dprintk printk
+#else
+#define dprintk(...) do { } while (0)
+#endif
+
+/**
+ * tomoyo_commit_condition - Commit "struct tomoyo_condition".
+ *
+ * @entry: Pointer to "struct tomoyo_condition".
+ *
+ * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
+ *
+ * This function merges duplicated entries. This function returns NULL if
+ * @entry is not duplicated but memory quota for policy has exceeded.
+ */
+static struct tomoyo_condition *tomoyo_commit_condition
+(struct tomoyo_condition *entry)
+{
+	struct tomoyo_condition *ptr;
+	bool found = false;
+
+	if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
+		dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
+		ptr = NULL;
+		found = true;
+		goto out;
+	}
+	list_for_each_entry(ptr, &tomoyo_condition_list, head.list) {
+		if (!tomoyo_same_condition(ptr, entry) ||
+		    atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)
+			continue;
+		/* Same entry found. Share this entry. */
+		atomic_inc(&ptr->head.users);
+		found = true;
+		break;
+	}
+	if (!found) {
+		if (tomoyo_memory_ok(entry)) {
+			atomic_set(&entry->head.users, 1);
+			list_add(&entry->head.list, &tomoyo_condition_list);
+		} else {
+			found = true;
+			ptr = NULL;
+		}
+	}
+	mutex_unlock(&tomoyo_policy_lock);
+out:
+	if (found) {
+		tomoyo_del_condition(&entry->head.list);
+		kfree(entry);
+		entry = ptr;
+	}
+	return entry;
+}
+
+/**
+ * tomoyo_get_transit_preference - Parse domain transition preference for execve().
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ * @e:     Pointer to "struct tomoyo_condition".
+ *
+ * Returns the condition string part.
+ */
+static char *tomoyo_get_transit_preference(struct tomoyo_acl_param *param,
+					   struct tomoyo_condition *e)
+{
+	char * const pos = param->data;
+	bool flag;
+
+	if (*pos == '<') {
+		e->transit = tomoyo_get_domainname(param);
+		goto done;
+	}
+	{
+		char *cp = strchr(pos, ' ');
+
+		if (cp)
+			*cp = '\0';
+		flag = tomoyo_correct_path(pos) || !strcmp(pos, "keep") ||
+			!strcmp(pos, "initialize") || !strcmp(pos, "reset") ||
+			!strcmp(pos, "child") || !strcmp(pos, "parent");
+		if (cp)
+			*cp = ' ';
+	}
+	if (!flag)
+		return pos;
+	e->transit = tomoyo_get_name(tomoyo_read_token(param));
+done:
+	if (e->transit)
+		return param->data;
+	/*
+	 * Return a bad read-only condition string that will let
+	 * tomoyo_get_condition() return NULL.
+	 */
+	return "/";
+}
+
+/**
+ * tomoyo_get_condition - Parse condition part.
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ *
+ * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
+ */
+struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
+{
+	struct tomoyo_condition *entry = NULL;
+	struct tomoyo_condition_element *condp = NULL;
+	struct tomoyo_number_union *numbers_p = NULL;
+	struct tomoyo_name_union *names_p = NULL;
+	struct tomoyo_argv *argv = NULL;
+	struct tomoyo_envp *envp = NULL;
+	struct tomoyo_condition e = { };
+	char * const start_of_string =
+		tomoyo_get_transit_preference(param, &e);
+	char * const end_of_string = start_of_string + strlen(start_of_string);
+	char *pos;
+
+rerun:
+	pos = start_of_string;
+	while (1) {
+		u8 left = -1;
+		u8 right = -1;
+		char *left_word = pos;
+		char *cp;
+		char *right_word;
+		bool is_not;
+
+		if (!*left_word)
+			break;
+		/*
+		 * Since left-hand condition does not allow use of "path_group"
+		 * or "number_group" and environment variable's names do not
+		 * accept '=', it is guaranteed that the original line consists
+		 * of one or more repetition of $left$operator$right blocks
+		 * where "$left is free from '=' and ' '" and "$operator is
+		 * either '=' or '!='" and "$right is free from ' '".
+		 * Therefore, we can reconstruct the original line at the end
+		 * of dry run even if we overwrite $operator with '\0'.
+		 */
+		cp = strchr(pos, ' ');
+		if (cp) {
+			*cp = '\0'; /* Will restore later. */
+			pos = cp + 1;
+		} else {
+			pos = "";
+		}
+		right_word = strchr(left_word, '=');
+		if (!right_word || right_word == left_word)
+			goto out;
+		is_not = *(right_word - 1) == '!';
+		if (is_not)
+			*(right_word++ - 1) = '\0'; /* Will restore later. */
+		else if (*(right_word + 1) != '=')
+			*right_word++ = '\0'; /* Will restore later. */
+		else
+			goto out;
+		dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
+			is_not ? "!" : "", right_word);
+		if (!strcmp(left_word, "grant_log")) {
+			if (entry) {
+				if (is_not ||
+				    entry->grant_log != TOMOYO_GRANTLOG_AUTO)
+					goto out;
+				else if (!strcmp(right_word, "yes"))
+					entry->grant_log = TOMOYO_GRANTLOG_YES;
+				else if (!strcmp(right_word, "no"))
+					entry->grant_log = TOMOYO_GRANTLOG_NO;
+				else
+					goto out;
+			}
+			continue;
+		}
+		if (!strncmp(left_word, "exec.argv[", 10)) {
+			if (!argv) {
+				e.argc++;
+				e.condc++;
+			} else {
+				e.argc--;
+				e.condc--;
+				left = TOMOYO_ARGV_ENTRY;
+				argv->is_not = is_not;
+				if (!tomoyo_parse_argv(left_word + 10,
+						       right_word, argv++))
+					goto out;
+			}
+			goto store_value;
+		}
+		if (!strncmp(left_word, "exec.envp[\"", 11)) {
+			if (!envp) {
+				e.envc++;
+				e.condc++;
+			} else {
+				e.envc--;
+				e.condc--;
+				left = TOMOYO_ENVP_ENTRY;
+				envp->is_not = is_not;
+				if (!tomoyo_parse_envp(left_word + 11,
+						       right_word, envp++))
+					goto out;
+			}
+			goto store_value;
+		}
+		left = tomoyo_condition_type(left_word);
+		dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
+			left);
+		if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
+			if (!numbers_p) {
+				e.numbers_count++;
+			} else {
+				e.numbers_count--;
+				left = TOMOYO_NUMBER_UNION;
+				param->data = left_word;
+				if (*left_word == '@' ||
+				    !tomoyo_parse_number_union(param,
+							       numbers_p++))
+					goto out;
+			}
+		}
+		if (!condp)
+			e.condc++;
+		else
+			e.condc--;
+		if (left == TOMOYO_EXEC_REALPATH ||
+		    left == TOMOYO_SYMLINK_TARGET) {
+			if (!names_p) {
+				e.names_count++;
+			} else {
+				e.names_count--;
+				right = TOMOYO_NAME_UNION;
+				param->data = right_word;
+				if (!tomoyo_parse_name_union_quoted(param,
+								    names_p++))
+					goto out;
+			}
+			goto store_value;
+		}
+		right = tomoyo_condition_type(right_word);
+		if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
+			if (!numbers_p) {
+				e.numbers_count++;
+			} else {
+				e.numbers_count--;
+				right = TOMOYO_NUMBER_UNION;
+				param->data = right_word;
+				if (!tomoyo_parse_number_union(param,
+							       numbers_p++))
+					goto out;
+			}
+		}
+store_value:
+		if (!condp) {
+			dprintk(KERN_WARNING "%u: dry_run left=%u right=%u match=%u\n",
+				__LINE__, left, right, !is_not);
+			continue;
+		}
+		condp->left = left;
+		condp->right = right;
+		condp->equals = !is_not;
+		dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n",
+			__LINE__, condp->left, condp->right,
+			condp->equals);
+		condp++;
+	}
+	dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u\n",
+		__LINE__, e.condc, e.numbers_count, e.names_count, e.argc,
+		e.envc);
+	if (entry) {
+		BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc |
+		       e.condc);
+		return tomoyo_commit_condition(entry);
+	}
+	e.size = sizeof(*entry)
+		+ e.condc * sizeof(struct tomoyo_condition_element)
+		+ e.numbers_count * sizeof(struct tomoyo_number_union)
+		+ e.names_count * sizeof(struct tomoyo_name_union)
+		+ e.argc * sizeof(struct tomoyo_argv)
+		+ e.envc * sizeof(struct tomoyo_envp);
+	entry = kzalloc(e.size, GFP_NOFS);
+	if (!entry)
+		goto out2;
+	*entry = e;
+	e.transit = NULL;
+	condp = (struct tomoyo_condition_element *) (entry + 1);
+	numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
+	names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count);
+	argv = (struct tomoyo_argv *) (names_p + e.names_count);
+	envp = (struct tomoyo_envp *) (argv + e.argc);
+	{
+		bool flag = false;
+
+		for (pos = start_of_string; pos < end_of_string; pos++) {
+			if (*pos)
+				continue;
+			if (flag) /* Restore " ". */
+				*pos = ' ';
+			else if (*(pos + 1) == '=') /* Restore "!=". */
+				*pos = '!';
+			else /* Restore "=". */
+				*pos = '=';
+			flag = !flag;
+		}
+	}
+	goto rerun;
+out:
+	dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
+	if (entry) {
+		tomoyo_del_condition(&entry->head.list);
+		kfree(entry);
+	}
+out2:
+	tomoyo_put_name(e.transit);
+	return NULL;
+}
+
+/**
+ * tomoyo_get_attributes - Revalidate "struct inode".
+ *
+ * @obj: Pointer to "struct tomoyo_obj_info".
+ *
+ * Returns nothing.
+ */
+void tomoyo_get_attributes(struct tomoyo_obj_info *obj)
+{
+	u8 i;
+	struct dentry *dentry = NULL;
+
+	for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
+		struct inode *inode;
+
+		switch (i) {
+		case TOMOYO_PATH1:
+			dentry = obj->path1.dentry;
+			if (!dentry)
+				continue;
+			break;
+		case TOMOYO_PATH2:
+			dentry = obj->path2.dentry;
+			if (!dentry)
+				continue;
+			break;
+		default:
+			if (!dentry)
+				continue;
+			dentry = dget_parent(dentry);
+			break;
+		}
+		inode = d_backing_inode(dentry);
+		if (inode) {
+			struct tomoyo_mini_stat *stat = &obj->stat[i];
+
+			stat->uid  = inode->i_uid;
+			stat->gid  = inode->i_gid;
+			stat->ino  = inode->i_ino;
+			stat->mode = inode->i_mode;
+			stat->dev  = inode->i_sb->s_dev;
+			stat->rdev = inode->i_rdev;
+			obj->stat_valid[i] = true;
+		}
+		if (i & 1) /* TOMOYO_PATH1_PARENT or TOMOYO_PATH2_PARENT */
+			dput(dentry);
+	}
+}
+
+/**
+ * tomoyo_condition - Check condition part.
+ *
+ * @r:    Pointer to "struct tomoyo_request_info".
+ * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
+ *
+ * Returns true on success, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+bool tomoyo_condition(struct tomoyo_request_info *r,
+		      const struct tomoyo_condition *cond)
+{
+	u32 i;
+	unsigned long min_v[2] = { 0, 0 };
+	unsigned long max_v[2] = { 0, 0 };
+	const struct tomoyo_condition_element *condp;
+	const struct tomoyo_number_union *numbers_p;
+	const struct tomoyo_name_union *names_p;
+	const struct tomoyo_argv *argv;
+	const struct tomoyo_envp *envp;
+	struct tomoyo_obj_info *obj;
+	u16 condc;
+	u16 argc;
+	u16 envc;
+	struct linux_binprm *bprm = NULL;
+
+	if (!cond)
+		return true;
+	condc = cond->condc;
+	argc = cond->argc;
+	envc = cond->envc;
+	obj = r->obj;
+	if (r->ee)
+		bprm = r->ee->bprm;
+	if (!bprm && (argc || envc))
+		return false;
+	condp = (struct tomoyo_condition_element *) (cond + 1);
+	numbers_p = (const struct tomoyo_number_union *) (condp + condc);
+	names_p = (const struct tomoyo_name_union *)
+		(numbers_p + cond->numbers_count);
+	argv = (const struct tomoyo_argv *) (names_p + cond->names_count);
+	envp = (const struct tomoyo_envp *) (argv + argc);
+	for (i = 0; i < condc; i++) {
+		const bool match = condp->equals;
+		const u8 left = condp->left;
+		const u8 right = condp->right;
+		bool is_bitop[2] = { false, false };
+		u8 j;
+
+		condp++;
+		/* Check argv[] and envp[] later. */
+		if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY)
+			continue;
+		/* Check string expressions. */
+		if (right == TOMOYO_NAME_UNION) {
+			const struct tomoyo_name_union *ptr = names_p++;
+			struct tomoyo_path_info *symlink;
+			struct tomoyo_execve *ee;
+			struct file *file;
+
+			switch (left) {
+			case TOMOYO_SYMLINK_TARGET:
+				symlink = obj ? obj->symlink_target : NULL;
+				if (!symlink ||
+				    !tomoyo_compare_name_union(symlink, ptr)
+				    == match)
+					goto out;
+				break;
+			case TOMOYO_EXEC_REALPATH:
+				ee = r->ee;
+				file = ee ? ee->bprm->file : NULL;
+				if (!tomoyo_scan_exec_realpath(file, ptr,
+							       match))
+					goto out;
+				break;
+			}
+			continue;
+		}
+		/* Check numeric or bit-op expressions. */
+		for (j = 0; j < 2; j++) {
+			const u8 index = j ? right : left;
+			unsigned long value = 0;
+
+			switch (index) {
+			case TOMOYO_TASK_UID:
+				value = from_kuid(&init_user_ns, current_uid());
+				break;
+			case TOMOYO_TASK_EUID:
+				value = from_kuid(&init_user_ns, current_euid());
+				break;
+			case TOMOYO_TASK_SUID:
+				value = from_kuid(&init_user_ns, current_suid());
+				break;
+			case TOMOYO_TASK_FSUID:
+				value = from_kuid(&init_user_ns, current_fsuid());
+				break;
+			case TOMOYO_TASK_GID:
+				value = from_kgid(&init_user_ns, current_gid());
+				break;
+			case TOMOYO_TASK_EGID:
+				value = from_kgid(&init_user_ns, current_egid());
+				break;
+			case TOMOYO_TASK_SGID:
+				value = from_kgid(&init_user_ns, current_sgid());
+				break;
+			case TOMOYO_TASK_FSGID:
+				value = from_kgid(&init_user_ns, current_fsgid());
+				break;
+			case TOMOYO_TASK_PID:
+				value = tomoyo_sys_getpid();
+				break;
+			case TOMOYO_TASK_PPID:
+				value = tomoyo_sys_getppid();
+				break;
+			case TOMOYO_TYPE_IS_SOCKET:
+				value = S_IFSOCK;
+				break;
+			case TOMOYO_TYPE_IS_SYMLINK:
+				value = S_IFLNK;
+				break;
+			case TOMOYO_TYPE_IS_FILE:
+				value = S_IFREG;
+				break;
+			case TOMOYO_TYPE_IS_BLOCK_DEV:
+				value = S_IFBLK;
+				break;
+			case TOMOYO_TYPE_IS_DIRECTORY:
+				value = S_IFDIR;
+				break;
+			case TOMOYO_TYPE_IS_CHAR_DEV:
+				value = S_IFCHR;
+				break;
+			case TOMOYO_TYPE_IS_FIFO:
+				value = S_IFIFO;
+				break;
+			case TOMOYO_MODE_SETUID:
+				value = S_ISUID;
+				break;
+			case TOMOYO_MODE_SETGID:
+				value = S_ISGID;
+				break;
+			case TOMOYO_MODE_STICKY:
+				value = S_ISVTX;
+				break;
+			case TOMOYO_MODE_OWNER_READ:
+				value = 0400;
+				break;
+			case TOMOYO_MODE_OWNER_WRITE:
+				value = 0200;
+				break;
+			case TOMOYO_MODE_OWNER_EXECUTE:
+				value = 0100;
+				break;
+			case TOMOYO_MODE_GROUP_READ:
+				value = 0040;
+				break;
+			case TOMOYO_MODE_GROUP_WRITE:
+				value = 0020;
+				break;
+			case TOMOYO_MODE_GROUP_EXECUTE:
+				value = 0010;
+				break;
+			case TOMOYO_MODE_OTHERS_READ:
+				value = 0004;
+				break;
+			case TOMOYO_MODE_OTHERS_WRITE:
+				value = 0002;
+				break;
+			case TOMOYO_MODE_OTHERS_EXECUTE:
+				value = 0001;
+				break;
+			case TOMOYO_EXEC_ARGC:
+				if (!bprm)
+					goto out;
+				value = bprm->argc;
+				break;
+			case TOMOYO_EXEC_ENVC:
+				if (!bprm)
+					goto out;
+				value = bprm->envc;
+				break;
+			case TOMOYO_NUMBER_UNION:
+				/* Fetch values later. */
+				break;
+			default:
+				if (!obj)
+					goto out;
+				if (!obj->validate_done) {
+					tomoyo_get_attributes(obj);
+					obj->validate_done = true;
+				}
+				{
+					u8 stat_index;
+					struct tomoyo_mini_stat *stat;
+
+					switch (index) {
+					case TOMOYO_PATH1_UID:
+					case TOMOYO_PATH1_GID:
+					case TOMOYO_PATH1_INO:
+					case TOMOYO_PATH1_MAJOR:
+					case TOMOYO_PATH1_MINOR:
+					case TOMOYO_PATH1_TYPE:
+					case TOMOYO_PATH1_DEV_MAJOR:
+					case TOMOYO_PATH1_DEV_MINOR:
+					case TOMOYO_PATH1_PERM:
+						stat_index = TOMOYO_PATH1;
+						break;
+					case TOMOYO_PATH2_UID:
+					case TOMOYO_PATH2_GID:
+					case TOMOYO_PATH2_INO:
+					case TOMOYO_PATH2_MAJOR:
+					case TOMOYO_PATH2_MINOR:
+					case TOMOYO_PATH2_TYPE:
+					case TOMOYO_PATH2_DEV_MAJOR:
+					case TOMOYO_PATH2_DEV_MINOR:
+					case TOMOYO_PATH2_PERM:
+						stat_index = TOMOYO_PATH2;
+						break;
+					case TOMOYO_PATH1_PARENT_UID:
+					case TOMOYO_PATH1_PARENT_GID:
+					case TOMOYO_PATH1_PARENT_INO:
+					case TOMOYO_PATH1_PARENT_PERM:
+						stat_index =
+							TOMOYO_PATH1_PARENT;
+						break;
+					case TOMOYO_PATH2_PARENT_UID:
+					case TOMOYO_PATH2_PARENT_GID:
+					case TOMOYO_PATH2_PARENT_INO:
+					case TOMOYO_PATH2_PARENT_PERM:
+						stat_index =
+							TOMOYO_PATH2_PARENT;
+						break;
+					default:
+						goto out;
+					}
+					if (!obj->stat_valid[stat_index])
+						goto out;
+					stat = &obj->stat[stat_index];
+					switch (index) {
+					case TOMOYO_PATH1_UID:
+					case TOMOYO_PATH2_UID:
+					case TOMOYO_PATH1_PARENT_UID:
+					case TOMOYO_PATH2_PARENT_UID:
+						value = from_kuid(&init_user_ns, stat->uid);
+						break;
+					case TOMOYO_PATH1_GID:
+					case TOMOYO_PATH2_GID:
+					case TOMOYO_PATH1_PARENT_GID:
+					case TOMOYO_PATH2_PARENT_GID:
+						value = from_kgid(&init_user_ns, stat->gid);
+						break;
+					case TOMOYO_PATH1_INO:
+					case TOMOYO_PATH2_INO:
+					case TOMOYO_PATH1_PARENT_INO:
+					case TOMOYO_PATH2_PARENT_INO:
+						value = stat->ino;
+						break;
+					case TOMOYO_PATH1_MAJOR:
+					case TOMOYO_PATH2_MAJOR:
+						value = MAJOR(stat->dev);
+						break;
+					case TOMOYO_PATH1_MINOR:
+					case TOMOYO_PATH2_MINOR:
+						value = MINOR(stat->dev);
+						break;
+					case TOMOYO_PATH1_TYPE:
+					case TOMOYO_PATH2_TYPE:
+						value = stat->mode & S_IFMT;
+						break;
+					case TOMOYO_PATH1_DEV_MAJOR:
+					case TOMOYO_PATH2_DEV_MAJOR:
+						value = MAJOR(stat->rdev);
+						break;
+					case TOMOYO_PATH1_DEV_MINOR:
+					case TOMOYO_PATH2_DEV_MINOR:
+						value = MINOR(stat->rdev);
+						break;
+					case TOMOYO_PATH1_PERM:
+					case TOMOYO_PATH2_PERM:
+					case TOMOYO_PATH1_PARENT_PERM:
+					case TOMOYO_PATH2_PARENT_PERM:
+						value = stat->mode & S_IALLUGO;
+						break;
+					}
+				}
+				break;
+			}
+			max_v[j] = value;
+			min_v[j] = value;
+			switch (index) {
+			case TOMOYO_MODE_SETUID:
+			case TOMOYO_MODE_SETGID:
+			case TOMOYO_MODE_STICKY:
+			case TOMOYO_MODE_OWNER_READ:
+			case TOMOYO_MODE_OWNER_WRITE:
+			case TOMOYO_MODE_OWNER_EXECUTE:
+			case TOMOYO_MODE_GROUP_READ:
+			case TOMOYO_MODE_GROUP_WRITE:
+			case TOMOYO_MODE_GROUP_EXECUTE:
+			case TOMOYO_MODE_OTHERS_READ:
+			case TOMOYO_MODE_OTHERS_WRITE:
+			case TOMOYO_MODE_OTHERS_EXECUTE:
+				is_bitop[j] = true;
+			}
+		}
+		if (left == TOMOYO_NUMBER_UNION) {
+			/* Fetch values now. */
+			const struct tomoyo_number_union *ptr = numbers_p++;
+
+			min_v[0] = ptr->values[0];
+			max_v[0] = ptr->values[1];
+		}
+		if (right == TOMOYO_NUMBER_UNION) {
+			/* Fetch values now. */
+			const struct tomoyo_number_union *ptr = numbers_p++;
+
+			if (ptr->group) {
+				if (tomoyo_number_matches_group(min_v[0],
+								max_v[0],
+								ptr->group)
+				    == match)
+					continue;
+			} else {
+				if ((min_v[0] <= ptr->values[1] &&
+				     max_v[0] >= ptr->values[0]) == match)
+					continue;
+			}
+			goto out;
+		}
+		/*
+		 * Bit operation is valid only when counterpart value
+		 * represents permission.
+		 */
+		if (is_bitop[0] && is_bitop[1]) {
+			goto out;
+		} else if (is_bitop[0]) {
+			switch (right) {
+			case TOMOYO_PATH1_PERM:
+			case TOMOYO_PATH1_PARENT_PERM:
+			case TOMOYO_PATH2_PERM:
+			case TOMOYO_PATH2_PARENT_PERM:
+				if (!(max_v[0] & max_v[1]) == !match)
+					continue;
+			}
+			goto out;
+		} else if (is_bitop[1]) {
+			switch (left) {
+			case TOMOYO_PATH1_PERM:
+			case TOMOYO_PATH1_PARENT_PERM:
+			case TOMOYO_PATH2_PERM:
+			case TOMOYO_PATH2_PARENT_PERM:
+				if (!(max_v[0] & max_v[1]) == !match)
+					continue;
+			}
+			goto out;
+		}
+		/* Normal value range comparison. */
+		if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
+			continue;
+out:
+		return false;
+	}
+	/* Check argv[] and envp[] now. */
+	if (r->ee && (argc || envc))
+		return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp);
+	return true;
+}