TOMOYO: Allow wildcard for execute permission.

Some applications create and execute programs dynamically. We need to accept
wildcard for execute permission because such programs contain random suffix
in their filenames. This patch loosens up regulation of string parameters.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 59 insertions, 95 deletions

diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
index 7b023f5e131..592b76a2bce 100644
--- a/security/tomoyo/util.c
+++ b/security/tomoyo/util.c
@@ -89,7 +89,7 @@ void tomoyo_print_ulong(char *buffer, const int buffer_len,
 bool tomoyo_parse_name_union(const char *filename,
 			     struct tomoyo_name_union *ptr)
 {
-	if (!tomoyo_is_correct_path(filename, 0, 0, 0))
+	if (!tomoyo_is_correct_word(filename))
 		return false;
 	if (filename[0] == '@') {
 		ptr->group = tomoyo_get_path_group(filename + 1);
@@ -115,7 +115,7 @@ bool tomoyo_parse_number_union(char *data, struct tomoyo_number_union *num)
 	unsigned long v;
 	memset(num, 0, sizeof(*num));
 	if (data[0] == '@') {
-		if (!tomoyo_is_correct_path(data, 0, 0, 0))
+		if (!tomoyo_is_correct_word(data))
 			return false;
 		num->group = tomoyo_get_number_group(data + 1);
 		num->is_group = true;
@@ -265,54 +265,29 @@ bool tomoyo_tokenize(char *buffer, char *w[], size_t size)
 }
 
 /**
- * tomoyo_is_correct_path - Validate a pathname.
+ * tomoyo_is_correct_word2 - Validate a string.
  *
- * @filename:     The pathname to check.
- * @start_type:   Should the pathname start with '/'?
- *                1 = must / -1 = must not / 0 = don't care
- * @pattern_type: Can the pathname contain a wildcard?
- *                1 = must / -1 = must not / 0 = don't care
- * @end_type:     Should the pathname end with '/'?
- *                1 = must / -1 = must not / 0 = don't care
+ * @string: The string to check. May be non-'\0'-terminated.
+ * @len:    Length of @string.
  *
- * Check whether the given filename follows the naming rules.
- * Returns true if @filename follows the naming rules, false otherwise.
+ * Check whether the given string follows the naming rules.
+ * Returns true if @string follows the naming rules, false otherwise.
  */
-bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
-			    const s8 pattern_type, const s8 end_type)
+static bool tomoyo_is_correct_word2(const char *string, size_t len)
 {
-	const char *const start = filename;
+	const char *const start = string;
 	bool in_repetition = false;
-	bool contains_pattern = false;
 	unsigned char c;
 	unsigned char d;
 	unsigned char e;
-
-	if (!filename)
+	if (!len)
 		goto out;
-	c = *filename;
-	if (start_type == 1) { /* Must start with '/' */
-		if (c != '/')
-			goto out;
-	} else if (start_type == -1) { /* Must not start with '/' */
-		if (c == '/')
-			goto out;
-	}
-	if (c)
-		c = *(filename + strlen(filename) - 1);
-	if (end_type == 1) { /* Must end with '/' */
-		if (c != '/')
-			goto out;
-	} else if (end_type == -1) { /* Must not end with '/' */
-		if (c == '/')
-			goto out;
-	}
-	while (1) {
-		c = *filename++;
-		if (!c)
-			break;
+	while (len--) {
+		c = *string++;
 		if (c == '\\') {
-			c = *filename++;
+			if (!len--)
+				goto out;
+			c = *string++;
 			switch (c) {
 			case '\\':  /* "\\" */
 				continue;
@@ -326,21 +301,14 @@ bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 			case 'a':   /* "\a" */
 			case 'A':   /* "\A" */
 			case '-':   /* "\-" */
-				if (pattern_type == -1)
-					break; /* Must not contain pattern */
-				contains_pattern = true;
 				continue;
 			case '{':   /* "/\{" */
-				if (filename - 3 < start ||
-				    *(filename - 3) != '/')
+				if (string - 3 < start || *(string - 3) != '/')
 					break;
-				if (pattern_type == -1)
-					break; /* Must not contain pattern */
-				contains_pattern = true;
 				in_repetition = true;
 				continue;
 			case '}':   /* "\}/" */
-				if (*filename != '/')
+				if (*string != '/')
 					break;
 				if (!in_repetition)
 					break;
@@ -350,11 +318,11 @@ bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 			case '1':
 			case '2':
 			case '3':
-				d = *filename++;
-				if (d < '0' || d > '7')
+				if (!len-- || !len--)
 					break;
-				e = *filename++;
-				if (e < '0' || e > '7')
+				d = *string++;
+				e = *string++;
+				if (d < '0' || d > '7' || e < '0' || e > '7')
 					break;
 				c = tomoyo_make_byte(c, d, e);
 				if (tomoyo_is_invalid(c))
@@ -367,10 +335,6 @@ bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 			goto out;
 		}
 	}
-	if (pattern_type == 1) { /* Must contain pattern */
-		if (!contains_pattern)
-			goto out;
-	}
 	if (in_repetition)
 		goto out;
 	return true;
@@ -379,58 +343,58 @@ bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 }
 
 /**
+ * tomoyo_is_correct_word - Validate a string.
+ *
+ * @string: The string to check.
+ *
+ * Check whether the given string follows the naming rules.
+ * Returns true if @string follows the naming rules, false otherwise.
+ */
+bool tomoyo_is_correct_word(const char *string)
+{
+	return tomoyo_is_correct_word2(string, strlen(string));
+}
+
+/**
+ * tomoyo_is_correct_path - Validate a pathname.
+ *
+ * @filename: The pathname to check.
+ *
+ * Check whether the given pathname follows the naming rules.
+ * Returns true if @filename follows the naming rules, false otherwise.
+ */
+bool tomoyo_is_correct_path(const char *filename)
+{
+	return *filename == '/' && tomoyo_is_correct_word(filename);
+}
+
+/**
  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
  *
- * @domainname:   The domainname to check.
+ * @domainname: The domainname to check.
  *
  * Returns true if @domainname follows the naming rules, false otherwise.
  */
 bool tomoyo_is_correct_domain(const unsigned char *domainname)
 {
-	unsigned char c;
-	unsigned char d;
-	unsigned char e;
-
 	if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 				   TOMOYO_ROOT_NAME_LEN))
 		goto out;
 	domainname += TOMOYO_ROOT_NAME_LEN;
 	if (!*domainname)
 		return true;
-	do {
-		if (*domainname++ != ' ')
-			goto out;
-		if (*domainname++ != '/')
+	if (*domainname++ != ' ')
+		goto out;
+	while (1) {
+		const unsigned char *cp = strchr(domainname, ' ');
+		if (!cp)
+			break;
+		if (*domainname != '/' ||
+		    !tomoyo_is_correct_word2(domainname, cp - domainname - 1))
 			goto out;
-		while ((c = *domainname) != '\0' && c != ' ') {
-			domainname++;
-			if (c == '\\') {
-				c = *domainname++;
-				switch ((c)) {
-				case '\\':  /* "\\" */
-					continue;
-				case '0':   /* "\ooo" */
-				case '1':
-				case '2':
-				case '3':
-					d = *domainname++;
-					if (d < '0' || d > '7')
-						break;
-					e = *domainname++;
-					if (e < '0' || e > '7')
-						break;
-					c = tomoyo_make_byte(c, d, e);
-					if (tomoyo_is_invalid(c))
-						/* pattern is not \000 */
-						continue;
-				}
-				goto out;
-			} else if (tomoyo_is_invalid(c)) {
-				goto out;
-			}
-		}
-	} while (*domainname);
-	return true;
+		domainname = cp + 1;
+	}
+	return tomoyo_is_correct_path(domainname);
  out:
 	return false;
 }