Bug #103648
Updated by Andreas Kienast 7 months ago
During TYPO3 Surfcamp 2024, multiple working groups encountered a serious bug in TYPO3 that leads to data loss in the filesystem. When images are uploaded into @fileadmin/@ and get rendered in the frontend, said files suddenly appear to get deleted on the filesystem. After some investigation this was identified that it’s somehow related to symlinked @fileadmin/@ directories.
After a long debugging session we found out that latest refactorings in the image processing (#102679 and arguably #103351) are the culprit of this issue.
The issue is finally caused in @\TYPO3\CMS\Core\Resource\Processing\LocalCropScaleMaskHelper@ when it’s checked whether a separate image was generated:
<pre lang="php">
if ($result !== null) {
if ($result->getRealPath() !== $originalFileName) {
$result = [
</pre>
Since @fileadmin/@ is a symlink in the given scenario, @$originalFileName@ and @$result->getRealPath()@ differ, albeit they point to the very same file. In this case, @$result@ is not null, and is passed to @\TYPO3\CMS\Core\Resource\Processing\LocalImageProcessor@ which sets wrong information to the processing task, finally leading to a rename of the original file in @fileadmin/@ in @\TYPO3\CMS\Core\Resource\Driver\LocalDriver->addFile()`.
The following conditions must be fulfilled to trigger the bug:
# #. fileadmin/ must be a symlink
# #. the image being rendering must not need processing (e.g. by using an image with small dimensions).