Merge branch 'PHP-7.4'

* PHP-7.4:
  PCRE: Only remember valid UTF-8 if start offset zero
  PCRE: Check whether start offset is on char boundary
This commit is contained in:
Nikita Popov 2020-02-07 17:02:49 +01:00
commit d2befbc17d
2 changed files with 56 additions and 4 deletions

View file

@ -1109,6 +1109,22 @@ static void php_do_pcre_match(INTERNAL_FUNCTION_PARAMETERS, int global) /* {{{ *
} }
/* }}} */ /* }}} */
static zend_always_inline zend_bool is_known_valid_utf8(
zend_string *subject_str, PCRE2_SIZE start_offset) {
if (!(GC_FLAGS(subject_str) & IS_STR_VALID_UTF8)) {
/* We don't know whether the string is valid UTF-8 or not. */
return 0;
}
if (start_offset == ZSTR_LEN(subject_str)) {
/* Degenerate case: Offset points to end of string. */
return 1;
}
/* Check that the offset does not point to an UTF-8 continuation byte. */
return (ZSTR_VAL(subject_str)[start_offset] & 0xc0) != 0x80;
}
/* {{{ php_pcre_match_impl() */ /* {{{ php_pcre_match_impl() */
PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str, zval *return_value, PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str, zval *return_value,
zval *subpats, int global, int use_flags, zend_long flags, zend_off_t start_offset) zval *subpats, int global, int use_flags, zend_long flags, zend_off_t start_offset)
@ -1130,7 +1146,7 @@ PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str,
PCRE2_SPTR mark = NULL; /* Target for MARK name */ PCRE2_SPTR mark = NULL; /* Target for MARK name */
zval marks; /* Array of marks for PREG_PATTERN_ORDER */ zval marks; /* Array of marks for PREG_PATTERN_ORDER */
pcre2_match_data *match_data; pcre2_match_data *match_data;
PCRE2_SIZE start_offset2; PCRE2_SIZE start_offset2, orig_start_offset;
char *subject = ZSTR_VAL(subject_str); char *subject = ZSTR_VAL(subject_str);
size_t subject_len = ZSTR_LEN(subject_str); size_t subject_len = ZSTR_LEN(subject_str);
@ -1226,8 +1242,10 @@ PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str,
} }
} }
options = (pce->compile_options & PCRE2_UTF) && !(GC_FLAGS(subject_str) & IS_STR_VALID_UTF8) orig_start_offset = start_offset2;
? 0 : PCRE2_NO_UTF_CHECK; options =
(pce->compile_options & PCRE2_UTF) && !is_known_valid_utf8(subject_str, orig_start_offset)
? 0 : PCRE2_NO_UTF_CHECK;
/* Execute the regular expression. */ /* Execute the regular expression. */
#ifdef HAVE_PCRE_JIT_SUPPORT #ifdef HAVE_PCRE_JIT_SUPPORT
@ -1417,7 +1435,8 @@ error:
if (PCRE_G(error_code) == PHP_PCRE_NO_ERROR) { if (PCRE_G(error_code) == PHP_PCRE_NO_ERROR) {
/* If there was no error and we're in /u mode, remember that the string is valid UTF-8. */ /* If there was no error and we're in /u mode, remember that the string is valid UTF-8. */
if ((pce->compile_options & PCRE2_UTF) && !ZSTR_IS_INTERNED(subject_str)) { if ((pce->compile_options & PCRE2_UTF)
&& !ZSTR_IS_INTERNED(subject_str) && orig_start_offset == 0) {
GC_ADD_FLAGS(subject_str, IS_STR_VALID_UTF8); GC_ADD_FLAGS(subject_str, IS_STR_VALID_UTF8);
} }

View file

@ -0,0 +1,33 @@
--TEST--
Bug #79241: Segmentation fault on preg_match()
--FILE--
<?php
// if "" string is used directly without json_decode,
// the issue does not reproduce
$text = json_decode('""');
$pattern = '/\b/u';
// it has to be exact two calls to preg_match(),
// with the second call offsetting after the tick symbol
var_dump(preg_match($pattern, $text, $matches, 0, 0));
var_dump(preg_match($pattern, $text, $matches, 0, 1));
var_dump(preg_last_error() == PREG_BAD_UTF8_OFFSET_ERROR);
echo "\n";
$text = "VA\xff"; $text .= "LID";
var_dump(preg_match($pattern, $text, $matches, 0, 4));
var_dump(preg_match($pattern, $text, $matches, 0, 0));
var_dump(preg_last_error() == PREG_BAD_UTF8_ERROR);
?>
--EXPECT--
int(0)
bool(false)
bool(true)
int(1)
bool(false)
bool(true)