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ext/intl: Fix for the issue where strlen could potentially become negative #18477

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Merged
merged 1 commit into from
May 2, 2025
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ext/intl: Fix for the issue where strlen could potentially become negative #18477

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4 changes: 4 additions & 0 deletions ext/intl/grapheme/grapheme_string.c
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Original file line number Diff line number Diff line change
Expand Up @@ -994,6 +994,10 @@ PHP_FUNCTION(grapheme_levenshtein)
int32_t strlen_1, strlen_2;
strlen_1 = grapheme_split_string(ustring1, ustring1_len, NULL, 0);
strlen_2 = grapheme_split_string(ustring2, ustring2_len, NULL, 0);
if (UNEXPECTED(strlen_1 < 0 || strlen_2 < 0)) {
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before merging, and since that s the whole point of this PR. can you think of few test cases to trigger this code path ? Cheers.

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@devnexen

Logically, it seems to return -1 when a bad status is received, just like in the following location.

However, I can’t think of a specific way to intentionally reproduce that behavior…

php-src/ext/intl/grapheme/grapheme_string.c

Line 1010 in dd57332

if (U_FAILURE(ustatus)) {

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I tried something simpler, grapheme_strlen except U_MEMORY_ALLOCATION_ERROR I can t think of cases as bad inputs are caught up before that.

RETVAL_FALSE;
goto out_ustring2;
}

if (strlen_1 == 0) {
RETVAL_LONG(strlen_2 * cost_ins);
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