Bug #77552 [Opn->Csd]: Unintialized php_stream_statbuf in stat functions

Edit report at https://bugs.php.net/bug.php?id=77552&edit=1 ID: 77552 Updated by: nikic@php.net Reported by: john-stevenson at blueyonder dot co dot uk Summary: Unintialized php_stream_statbuf in stat functions -Status: Open +Status: Closed Type: Bug Package: Filesystem function related Operating System: Windows 10 PHP Version: 7.3.1 Block user comment: N Private report: N New Comment: Automatic comment on behalf of john-stevenson@blueyonder.co.uk Revision: http://git.php.net/?p=php-src.git;a=commit;h=fe4d7248cc09cf4d4f7b289e6db8299e8d7ac6d2 Log: Fix #77552: Uninitialized buffer in stat functions Previous Comments: ------------------------------------------------------------------------ [2019-02-02 11:18:00] The following pull request has been associated: Patch Name: Fix #77552: Uninitialized buffer in stat functions On GitHub: https://github.com/php/php-src/pull/3784 Patch: https://github.com/php/php-src/pull/3784.patch ------------------------------------------------------------------------ [2019-01-31 22:19:18] john-stevenson at blueyonder dot co dot uk Description: ------------ The php_stream_statbuf that is used in the filepath stat functions is uninitialized in function 'php_stat' (ext\standard\filestat.c). This can result in random st_mode values, when calling lstat on a NTFS junction. The 'php_sys_stat_ex' function (zend\zend_virtual_cwd.c) sets the st_mode for everything except a junction, so the uninitialized value is returned. The test script below just illustrates that it is uninitialized by using a debug build. On release builds the script will show the 'expected' mode value of 0, but when used in more complex scenarios (like a test suite) different values can be returned for junctions. For example, from my error log, while trying to track this down: [31-Jan-2019 21:52:39 UTC] PHP 7.3.1 [31-Jan-2019 21:52:39 UTC] mode: 53467, composer-test-27485c536e26d95fa/junction [31-Jan-2019 21:52:39 UTC] mode: 1508, composer-test-27485c536e26d95fa/junction [31-Jan-2019 21:52:39 UTC] mode: 18252, composer-test-27485c536e26d95fa/junction Of course, since there is no S_IFJUNC, it is hard to know what the 'expected' st_mode value should be. However Composer uses it to check for a junction (if it is a directory, not a link and not S_ISDIR from lstat's st_mode) and our tests are sometimes now failing on PHP 7.3 Test script: --------------- Create a junction: mkdir /J path/to/junction path/to/target Compile php with --enable-debug Run: php.exe -r "print_r(lstat('path/to/junction'));" Expected result: ---------------- ... [mode] => 0 ... Actual result: -------------- ... [mode] => 52428 ... ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=77552&edit=1