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Fix GH-14807 ext/standard levenshtein overflow on 3rd, 4th and 5th arguments. #14809

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Fix GH-14807 ext/standard levenshtein overflow on 3rd, 4th and 5th arguments. #14809

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34 changes: 34 additions & 0 deletions ext/standard/levenshtein.c
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@ static zend_long reference_levdist(const zend_string *string1, const zend_string
return ZSTR_LEN(string1) * cost_del;
}


p1 = safe_emalloc((ZSTR_LEN(string2) + 1), sizeof(zend_long), 0);
p2 = safe_emalloc((ZSTR_LEN(string2) + 1), sizeof(zend_long), 0);

Expand Down Expand Up @@ -78,6 +79,39 @@ PHP_FUNCTION(levenshtein)
RETURN_THROWS();
}

if (ZSTR_LEN(string1) > 0 || ZSTR_LEN(string2) > 0) {
zend_long lc = MAX(cost_ins, MAX(cost_rep, cost_del));
zend_long ml = MAX(ZSTR_LEN(string1), ZSTR_LEN(string2));
zend_long ovl = ZEND_LONG_MAX / ml;


if (lc > ovl) {
int arg = 3;
if (lc == cost_rep) {
arg = 4;
} else if (lc == cost_del) {
arg = 5;
}

zend_argument_value_error(arg, "must be at most " ZEND_LONG_FMT, ovl);
RETURN_THROWS();
}

zend_long mc = MIN(cost_ins, MIN(cost_rep, cost_del));
zend_long uvl = ZEND_LONG_MIN / ml;

if (mc < uvl) {
int arg = 3;
if (mc == cost_rep) {
arg = 4;
} else if (mc == cost_del) {
arg = 5;
}

zend_argument_value_error(arg, "must be at least " ZEND_LONG_FMT, uvl);
RETURN_THROWS();
}
}

RETURN_LONG(reference_levdist(string1, string2, cost_ins, cost_rep, cost_del));
}
Expand Down
38 changes: 38 additions & 0 deletions ext/standard/tests/strings/gh14807.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,38 @@
--TEST--
GH-14807 overflow on insertion_cost/replacement_cost/deletion_cost
--SKIPIF--
<?php
if (PHP_INT_SIZE != 8) die("skip this test is for 64bit platform only");
?>
--FILE--
<?php
$str1 = "abcd";
$str2 = "defg";

foreach([PHP_INT_MIN, PHP_INT_MAX] as $lim) {
try {
levenshtein($str1, $str2, $lim);
} catch (\ValueError $e) {
echo $e->getMessage() . PHP_EOL;
}

try {
levenshtein($str1, $str2, 1, $lim);
} catch (\ValueError $e) {
echo $e->getMessage() . PHP_EOL;
}

try {
levenshtein($str1, $str2, 1, 1, $lim);
} catch (\ValueError $e) {
echo $e->getMessage() . PHP_EOL;
}
}
?>
--EXPECTF--
levenshtein(): Argument #3 ($insertion_cost) must be at least %s
levenshtein(): Argument #4 ($replacement_cost) must be at least %s
levenshtein(): Argument #5 ($deletion_cost) must be at least %s
levenshtein(): Argument #3 ($insertion_cost) must be at most %s
levenshtein(): Argument #4 ($replacement_cost) must be at most %s
levenshtein(): Argument #5 ($deletion_cost) must be at most %s