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Better size check in bzdecompress #19069

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Better size check in bzdecompress #19069

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37e3c9e
Better size check in bzdecompress
marc-mabe Jul 8, 2025
2fde338
Use uint64_t and removed preprocessor checks
marc-mabe Aug 29, 2025
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18 changes: 5 additions & 13 deletions ext/bz2/bz2.c
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Original file line number Diff line number Diff line change
Expand Up @@ -493,11 +493,7 @@ PHP_FUNCTION(bzdecompress)
size_t source_len;
int error;
bool small = 0;
#ifdef PHP_WIN32
unsigned __int64 size = 0;
#else
unsigned long long size = 0;
#endif
uint64_t size = 0;
bz_stream bzs;

if (FAILURE == zend_parse_parameters(ZEND_NUM_ARGS(), "s|b", &source, &source_len, &small)) {
Expand All @@ -524,26 +520,22 @@ PHP_FUNCTION(bzdecompress)
/* compression is better then 2:1, need to allocate more memory */
bzs.avail_out = source_len;
size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
#ifndef ZEND_ENABLE_ZVAL_LONG64
if (size > SIZE_MAX) {
if (UNEXPECTED(size > SIZE_MAX)) {
/* no reason to continue if we're going to drop it anyway */
break;
}
#endif

dest = zend_string_safe_realloc(dest, 1, bzs.avail_out+1, (size_t) size, 0);
bzs.next_out = ZSTR_VAL(dest) + size;
}

if (error == BZ_STREAM_END || error == BZ_OK) {
size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
#ifndef ZEND_ENABLE_ZVAL_LONG64
if (UNEXPECTED(size > SIZE_MAX)) {
php_error_docref(NULL, E_WARNING, "Decompressed size too big, max is %zd", SIZE_MAX);
php_error_docref(NULL, E_WARNING, "Decompressed size too big, max is %zu", SIZE_MAX);
zend_string_efree(dest);
RETVAL_LONG(BZ_MEM_ERROR);
} else
#endif
{
} else {
dest = zend_string_safe_realloc(dest, 1, (size_t)size, 1, 0);
ZSTR_LEN(dest) = (size_t)size;
ZSTR_VAL(dest)[(size_t)size] = '\0';
Expand Down