Bug #75075 [NEW]: unpack with X* causes infinity loop

From: erik at datahack dot se Operating system: PHP version: 7.1.8 Package: Unknown/Other Function Bug Type: Bug Bug description:unpack with X* causes infinity loop Description: ------------ Using unpack with "X*" causes an infinity loop Test script: --------------- <?php unpack("X*", ""); Expected result: ---------------- I would expect either A. * to not be a valid repeater for X B. cause it to rewind to zero. Actual result: -------------- 100% CPU usage -- Edit bug report at https://bugs.php.net/bug.php?id=75075&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=75075&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=75075&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=75075&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=75075&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=75075&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=75075&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=75075&r=needscript Try newer version: https://bugs.php.net/fix.php?id=75075&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=75075&r=support Expected behavior: https://bugs.php.net/fix.php?id=75075&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=75075&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=75075&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=75075&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=75075&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=75075&r=dst IIS Stability: https://bugs.php.net/fix.php?id=75075&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=75075&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=75075&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=75075&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=75075&r=mysqlcfg