Internet Bug Bounty: efree() on uninitialized Heap data in imagescale leads to use-after-free

The core bug: https://bugs.php.net/bug.php?id=77269 This bugfix actually involves two vulnerabilities: a call to efree on uninitialized data and another free based vulnerability. What is described below is a bug that was fixed in libgd two years ago CVE-2016-10166, but the patch was never applied...