Fix crash when filter callback unsets StreamBucket::$data - #23466
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NickSdot
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Aug 26, 2026
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| } catch (Error $e) { | ||
| printf("%s: %s\n", get_class($e), $e->getMessage()); | ||
| } |
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| } catch (Error $e) { | |
| printf("%s: %s\n", get_class($e), $e->getMessage()); | |
| } | |
| } catch (Throwable $e) { | |
| echo $e::class, ': ', $e->getMessage()); | |
| } |
devnexen
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Aug 26, 2026
| @@ -424,6 +424,12 @@ static void php_stream_bucket_attach(int append, INTERNAL_FUNCTION_PARAMETERS) | |||
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| if (NULL != (pzdata = zend_read_property(NULL, Z_OBJ_P(zobject), "data", sizeof("data")-1, false, &rv))) { | |||
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note: not from your change but seems to me zend_read_property does not return NULL ?
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Correct, std read_property returns &EG(uninitialized_zval). Pre-existing.
| if (NULL != (pzdata = zend_read_property(NULL, Z_OBJ_P(zobject), "data", sizeof("data")-1, false, &rv))) { | ||
| ZVAL_DEREF(pzdata); | ||
| if (Z_TYPE_P(pzdata) != IS_STRING) { | ||
| if (!EG(exception)) { |
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can it be possible ? I do not think, but if I m wrong please add a test.
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You're right. $data is typed string.
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stream_bucket_prepend()/append() assumed a successful zend_read_property() of StreamBucket::$data always yields a string, but for an unset typed property it throws while returning &EG(uninitialized_zval), so Z_STRLEN_P() dereferenced a NULL string pointer and crashed when the brigade was consumed. Reject non-string reads up front (rethrowing any pending exception) so the bucket is never re-attached with undefined data; the sibling $bucket property path is already safe because zend_fetch_resource_ex() rejects non-resources. Closes phpGH-23466
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devnexen
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| if (NULL != (pzdata = zend_read_property(NULL, Z_OBJ_P(zobject), "data", sizeof("data")-1, false, &rv))) { | ||
| ZVAL_DEREF(pzdata); | ||
| if (Z_TYPE_P(pzdata) != IS_STRING) { |
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I meant that the type would be any different than string, that what I would assert IMO.
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Asserted the type is string.
iliaal
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stream_bucket_prepend()/append() assumed a successful zend_read_property() of StreamBucket::$data always yields a string, but for an unset typed property it throws while returning &EG(uninitialized_zval), so Z_STRLEN_P() dereferenced a NULL string pointer and crashed when the brigade was consumed. Reject non-string reads up front (rethrowing any pending exception) so the bucket is never re-attached with undefined data; the sibling $bucket property path is already safe because zend_fetch_resource_ex() rejects non-resources. Closes phpGH-23466
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stream_bucket_prepend()/append() assumed a successful zend_read_property() of StreamBucket::$data always yields a string, but for an unset typed property it throws while returning &EG(uninitialized_zval), so Z_STRLEN_P() dereferenced a NULL string pointer and crashed when the brigade was consumed. Reject non-string reads up front (rethrowing any pending exception) so the bucket is never re-attached with undefined data; the sibling $bucket property path is already safe because zend_fetch_resource_ex() rejects non-resources. Closes phpGH-23466
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stream_bucket_prepend() and stream_bucket_append() assumed a successful zend_read_property() of StreamBucket::$data always yields a string, but when the property has been unset in the filter callback the read throws while returning &EG(uninitialized_zval), so Z_STRLEN_P() dereferenced a NULL string pointer and crashed once the brigade was consumed. Non-string reads are now rejected up front with the pending exception rethrown, so a bucket is never re-attached with undefined data; the sibling $bucket property path is already safe because zend_fetch_resource_ex() rejects non-resources.