From c9e78e6d338cc46dcadb39b3e2df119fa969e72b Mon Sep 17 00:00:00 2001 From: Nikita Popov Date: Fri, 7 Feb 2020 16:39:06 +0100 Subject: PCRE: Check whether start offset is on char boundary We need not just the whole string to be UTF-8, but the start position to be on a character boundary as well. Check this by looking for a continuation byte. --- ext/pcre/php_pcre.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'ext/pcre/php_pcre.c') diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c index 481d564f66..104b8d4c97 100644 --- a/ext/pcre/php_pcre.c +++ b/ext/pcre/php_pcre.c @@ -1130,6 +1130,22 @@ 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() */ 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) @@ -1247,7 +1263,7 @@ 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) + options = (pce->compile_options & PCRE2_UTF) && !is_known_valid_utf8(subject_str, start_offset2) ? 0 : PCRE2_NO_UTF_CHECK; /* Execute the regular expression. */ -- cgit v1.2.1