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Fix GH-18642: Signed integer overflow in ext/phar fseek #18644

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Fix GH-18642: Signed integer overflow in ext/phar fseek #18644

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20 changes: 11 additions & 9 deletions ext/phar/stream.c
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Original file line number Diff line number Diff line change
Expand Up @@ -405,7 +405,7 @@ static int phar_stream_seek(php_stream *stream, zend_off_t offset, int whence, z
phar_entry_data *data = (phar_entry_data *)stream->abstract;
phar_entry_info *entry;
int res;
zend_off_t temp;
zend_ulong temp;

if (data->internal_file->link) {
entry = phar_get_link_source(data->internal_file);
Expand All @@ -415,26 +415,28 @@ static int phar_stream_seek(php_stream *stream, zend_off_t offset, int whence, z

switch (whence) {
case SEEK_END :
temp = data->zero + entry->uncompressed_filesize + offset;
temp = (zend_ulong) data->zero + (zend_ulong) entry->uncompressed_filesize + (zend_ulong) offset;
break;
case SEEK_CUR :
temp = data->zero + data->position + offset;
temp = (zend_ulong) data->zero + (zend_ulong) data->position + (zend_ulong) offset;
break;
case SEEK_SET :
temp = data->zero + offset;
temp = (zend_ulong) data->zero + (zend_ulong) offset;
break;
default:
temp = 0;
}
if (temp > data->zero + (zend_off_t) entry->uncompressed_filesize) {
*newoffset = -1;

zend_off_t temp_signed = (zend_off_t) temp;
if (temp_signed > data->zero + (zend_off_t) entry->uncompressed_filesize) {
*newoffset = -1; /* FIXME: this will invalidate the ZEND_ASSERT(stream->position >= 0); assertion in streams.c */
return -1;
}
if (temp < data->zero) {
*newoffset = -1;
if (temp_signed < data->zero) {
*newoffset = -1; /* FIXME: this will invalidate the ZEND_ASSERT(stream->position >= 0); assertion in streams.c */
return -1;
}
res = php_stream_seek(data->fp, temp, SEEK_SET);
res = php_stream_seek(data->fp, temp_signed, SEEK_SET);
*newoffset = php_stream_tell(data->fp) - data->zero;
data->position = *newoffset;
return res;
Expand Down
29 changes: 29 additions & 0 deletions ext/phar/tests/gh18642.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,29 @@
--TEST--
GH-18642 (Signed integer overflow in ext/phar fseek)
--EXTENSIONS--
phar
--INI--
phar.require_hash=0
--FILE--
<?php
require_once __DIR__ . '/files/phar_oo_test.inc';
class MyFile extends SplFileObject
{
}
$phar = new Phar($fname);
$phar->setInfoClass('MyFile');
$f = $phar['a.php'];
var_dump($f->fseek(PHP_INT_MAX));
var_dump($f->fseek(0));
var_dump($f->fseek(PHP_INT_MIN, SEEK_END));
var_dump($f->fseek(0, SEEK_SET));
var_dump($f->fseek(1, SEEK_CUR));
var_dump($f->fseek(PHP_INT_MAX, SEEK_CUR));
?>
--EXPECT--
int(-1)
int(0)
int(-1)
int(0)
int(0)
int(-1)
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