From: Christoph M. Becker Date: Sat, 29 Dec 2018 13:17:23 +0000 (+0100) Subject: Fix #77367: Negative size parameter in mb_split X-Git-Tag: php-7.3.2RC1~50 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e617f03066ce81d26f56c06d6bd7787c7de08703;p=php Fix #77367: Negative size parameter in mb_split When adding the last element to the result value of `mb_split`, the `chunk_pos` may point beyond the end of the string, in which case the unsigned `n` would underflow. Therefore, we check whether this is the case in the first place, and only calculate `n` otherwise. Since `n` is no longer used outside the block, we move its declaration inside. --- diff --git a/ext/mbstring/php_mbregex.c b/ext/mbstring/php_mbregex.c index 68922b6966..85219b00e4 100644 --- a/ext/mbstring/php_mbregex.c +++ b/ext/mbstring/php_mbregex.c @@ -1238,7 +1238,6 @@ PHP_FUNCTION(mb_split) size_t string_len; int err; - size_t n; zend_long count = -1; if (zend_parse_parameters(ZEND_NUM_ARGS(), "ss|l", &arg_pattern, &arg_pattern_len, &string, &string_len, &count) == FAILURE) { @@ -1296,8 +1295,8 @@ PHP_FUNCTION(mb_split) } /* otherwise we just have one last element to add to the array */ - n = ((OnigUChar *)(string + string_len) - chunk_pos); - if (n > 0) { + if ((OnigUChar *)(string + string_len) > chunk_pos) { + size_t n = ((OnigUChar *)(string + string_len) - chunk_pos); add_next_index_stringl(return_value, (char *)chunk_pos, n); } else { add_next_index_stringl(return_value, "", 0); diff --git a/ext/mbstring/tests/bug77367.phpt b/ext/mbstring/tests/bug77367.phpt new file mode 100644 index 0000000000..0ba76fd23c --- /dev/null +++ b/ext/mbstring/tests/bug77367.phpt @@ -0,0 +1,21 @@ +--TEST-- +Bug #77367 (Negative size parameter in mb_split) +--SKIPIF-- + +--FILE-- + +===DONE=== +--EXPECT-- +array(2) { + [0]=> + string(0) "" + [1]=> + string(0) "" +} +===DONE===