fix bug #55856: preg_replace should fail on trailing garbage

Author: smalyshev

NEWS

@@ -39,6 +39,10 @@ PHP                                                                        NEWS
 - Installation:
   . Fixed bug #62460 (php binaries installed as binary.dSYM). (Reeze Xia)
 
+- PCRE:
+  . Fixed bug #55856 (preg_replace should fail on trailing garbage). 
+    (reg dot php at alf dot nu)
+
 - PDO:
   . Fixed bug #62685 (Wrong return datatype in PDO::inTransaction()). (Laruence)
 

ext/pcre/php_pcre.c

@@ -275,7 +275,8 @@ PHPAPI pcre_cache_entry* pcre_get_compiled_regex_cache(char *regex, int regex_le
 	   get to the end without encountering a delimiter. */
 	while (isspace((int)*(unsigned char *)p)) p++;
 	if (*p == 0) {
-		php_error_docref(NULL TSRMLS_CC, E_WARNING, "Empty regular expression");
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, 
+						 p < regex + regex_len ? "Null byte in regex" : "Empty regular expression");
 		return NULL;
 	}
 
@@ -292,29 +293,25 @@ PHPAPI pcre_cache_entry* pcre_get_compiled_regex_cache(char *regex, int regex_le
 		delimiter = pp[5];
 	end_delimiter = delimiter;
 
+	pp = p;
+
 	if (start_delimiter == end_delimiter) {
 		/* We need to iterate through the pattern, searching for the ending delimiter,
 		   but skipping the backslashed delimiters.  If the ending delimiter is not
 		   found, display a warning. */
-		pp = p;
 		while (*pp != 0) {
 			if (*pp == '\\' && pp[1] != 0) pp++;
 			else if (*pp == delimiter)
 				break;
 			pp++;
 		}
-		if (*pp == 0) {
-			php_error_docref(NULL TSRMLS_CC,E_WARNING, "No ending delimiter '%c' found", delimiter);
-			return NULL;
-		}
 	} else {
 		/* We iterate through the pattern, searching for the matching ending
 		 * delimiter. For each matching starting delimiter, we increment nesting
 		 * level, and decrement it for each matching ending delimiter. If we
 		 * reach the end of the pattern without matching, display a warning.
 		 */
 		int brackets = 1; 	/* brackets nesting level */
-		pp = p;
 		while (*pp != 0) {
 			if (*pp == '\\' && pp[1] != 0) pp++;
 			else if (*pp == end_delimiter && --brackets <= 0)
@@ -323,10 +320,17 @@ PHPAPI pcre_cache_entry* pcre_get_compiled_regex_cache(char *regex, int regex_le
 				brackets++;
 			pp++;
 		}
-		if (*pp == 0) {
-			php_error_docref(NULL TSRMLS_CC,E_WARNING, "No ending matching delimiter '%c' found", end_delimiter);
-			return NULL;
+	}
+
+	if (*pp == 0) {
+		if (pp < regex + regex_len) {
+			php_error_docref(NULL TSRMLS_CC,E_WARNING, "Null byte in regex");
+		} else if (start_delimiter == end_delimiter) {
+			php_error_docref(NULL TSRMLS_CC,E_WARNING, "No ending delimiter '%c' found", delimiter);
+		} else {
+			php_error_docref(NULL TSRMLS_CC,E_WARNING, "No ending matching delimiter '%c' found", delimiter);
 		}
+		return NULL;
 	}
 
 	/* Make a copy of the actual pattern. */
@@ -337,7 +341,7 @@ PHPAPI pcre_cache_entry* pcre_get_compiled_regex_cache(char *regex, int regex_le
 
 	/* Parse through the options, setting appropriate flags.  Display
 	   a warning if we encounter an unknown modifier. */	
-	while (*pp != 0) {
+	while (pp < regex + regex_len) {
 		switch (*pp++) {
 			/* Perl compatible options */
 			case 'i':	coptions |= PCRE_CASELESS;		break;
@@ -368,7 +372,11 @@ PHPAPI pcre_cache_entry* pcre_get_compiled_regex_cache(char *regex, int regex_le
 				break;
 
 			default:
-				php_error_docref(NULL TSRMLS_CC,E_WARNING, "Unknown modifier '%c'", pp[-1]);
+				if (pp[-1]) {
+					php_error_docref(NULL TSRMLS_CC,E_WARNING, "Unknown modifier '%c'", pp[-1]);
+				} else {
+					php_error_docref(NULL TSRMLS_CC,E_WARNING, "Null byte in regex");
+				}
 				efree(pattern);
 				return NULL;
 		}

ext/pcre/tests/null_bytes.phpt

@@ -0,0 +1,42 @@
+--TEST--
+Zero byte test
+--FILE--
+<?php
+
+preg_match("\0//i", "");
+preg_match("/\0/i", "");
+preg_match("//\0i", "");
+preg_match("//i\0", "");
+preg_match("/\\\0/i", "");
+
+preg_match("\0[]i", "");
+preg_match("[\0]i", "");
+preg_match("[]\0i", "");
+preg_match("[]i\0", "");
+preg_match("[\\\0]i", "");
+
+preg_replace("/foo/e\0/i", "echo('Eek');", "");
+
+?>
+--EXPECTF--
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 3
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 4
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 5
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 6
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 7
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 9
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 10
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 11
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 12
+
+Warning: preg_match(): Null byte in regex in %snull_bytes.php on line 13
+
+Warning: preg_replace(): Null byte in regex in %snull_bytes.php on line 15