fixup! fix: Harden files scanner for invalid null access

5 files changed, 48 insertions, 38 deletions

diff --git a/apps/files_sharing/lib/Cache.php b/apps/files_sharing/lib/Cache.php
index 372dde198a0..350f4718712 100644
--- a/apps/files_sharing/lib/Cache.php
+++ b/apps/files_sharing/lib/Cache.php
@@ -63,12 +63,12 @@ class Cache extends CacheJail {
 				/** @var Jail $currentStorage */
 				$absoluteRoot = $currentStorage->getJailedPath($absoluteRoot);
 			}
-			$this->root = $absoluteRoot;
+			$this->root = $absoluteRoot ?? '';
 		}
 		return $this->root;
 	}
 
-	protected function getGetUnjailedRoot() {
+	protected function getGetUnjailedRoot(): string {
 		return $this->sourceRootInfo->getPath();
 	}
 
diff --git a/lib/private/Files/Cache/Cache.php b/lib/private/Files/Cache/Cache.php
index 5dcce6d8bbb..7fbb625050b 100644
--- a/lib/private/Files/Cache/Cache.php
+++ b/lib/private/Files/Cache/Cache.php
@@ -109,7 +109,7 @@ class Cache implements ICache {
 	/**
 	 * get the stored metadata of a file or folder
 	 *
-	 * @param string | int $file either the path of a file or folder or the file id for a file or folder
+	 * @param string|int $file either the path of a file or folder or the file id for a file or folder
 	 * @return ICacheEntry|false the cache entry as array or false if the file is not found in the cache
 	 */
 	public function get($file) {
@@ -131,15 +131,17 @@ class Cache implements ICache {
 		$data = $result->fetch();
 		$result->closeCursor();
 
-		//merge partial data
-		if (!$data && is_string($file) && isset($this->partial[$file])) {
-			return $this->partial[$file];
-		} elseif (!$data) {
-			return $data;
-		} else {
+		if ($data !== false) {
 			$data['metadata'] = $metadataQuery->extractMetadata($data)->asArray();
 			return self::cacheEntryFromData($data, $this->mimetypeLoader);
+		} else {
+			//merge partial data
+			if (is_string($file) && isset($this->partial[$file])) {
+				return $this->partial[$file];
+			}
 		}
+
+		return false;
 	}
 
 	/**
@@ -886,19 +888,23 @@ class Cache implements ICache {
 	/**
 	 * Re-calculate the folder size and the size of all parent folders
 	 *
-	 * @param string|boolean $path
-	 * @param array $data (optional) meta data of the folder
+	 * @param array|ICacheEntry|null $data (optional) meta data of the folder
 	 */
-	public function correctFolderSize($path, $data = null, $isBackgroundScan = false) {
+	public function correctFolderSize(string $path, $data = null, bool $isBackgroundScan = false): void {
 		$this->calculateFolderSize($path, $data);
+
 		if ($path !== '') {
 			$parent = dirname($path);
 			if ($parent === '.' || $parent === '/') {
 				$parent = '';
 			}
+
 			if ($isBackgroundScan) {
 				$parentData = $this->get($parent);
-				if ($parentData['size'] !== -1 && $this->getIncompleteChildrenCount($parentData['fileid']) === 0) {
+				if ($parentData !== false
+					&& $parentData['size'] !== -1
+					&& $this->getIncompleteChildrenCount($parentData['fileid']) === 0
+				) {
 					$this->correctFolderSize($parent, $parentData, $isBackgroundScan);
 				}
 			} else {
diff --git a/lib/private/Files/Cache/Scanner.php b/lib/private/Files/Cache/Scanner.php
index 2bf1203955e..404c9310108 100644
--- a/lib/private/Files/Cache/Scanner.php
+++ b/lib/private/Files/Cache/Scanner.php
@@ -108,7 +108,7 @@ class Scanner extends BasicEmitter implements IScanner {
 	 * @param string $file
 	 * @param int $reuseExisting
 	 * @param int $parentId
-	 * @param array|null|false $cacheData existing data in the cache for the file to be scanned
+	 * @param array|CacheEntry|null|false $cacheData existing data in the cache for the file to be scanned
 	 * @param bool $lock set to false to disable getting an additional read lock during scanning
 	 * @param array|null $data the metadata for the file, as returned by the storage
 	 * @return array|null an array of metadata of the scanned file
@@ -207,7 +207,7 @@ class Scanner extends BasicEmitter implements IScanner {
 					 * i.e. get all the values in $data that are not present in the cache already
 					 *
 					 * We need the OC implementation for usage of "getData" method below.
-				 	 * @var \OC\Files\Cache\CacheEntry $cacheData
+					 * @var \OC\Files\Cache\CacheEntry $cacheData
 					 */
 					$newData = $this->array_diff_assoc_multi($data, $cacheData->getData());
 					
diff --git a/lib/private/Files/Cache/Wrapper/CacheJail.php b/lib/private/Files/Cache/Wrapper/CacheJail.php
index ea0f992114a..87952543c23 100644
--- a/lib/private/Files/Cache/Wrapper/CacheJail.php
+++ b/lib/private/Files/Cache/Wrapper/CacheJail.php
@@ -21,19 +21,15 @@ use OCP\Files\Search\ISearchOperator;
  * Jail to a subdirectory of the wrapped cache
  */
 class CacheJail extends CacheWrapper {
-	/**
-	 * @var string
-	 */
-	protected $root;
-	protected $unjailedRoot;
+
+	protected string $unjailedRoot;
 
 	public function __construct(
 		?ICache $cache,
-		string $root,
+		protected string $root,
 		?CacheDependencies $dependencies = null,
 	) {
 		parent::__construct($cache, $dependencies);
-		$this->root = $root;
 
 		if ($cache instanceof CacheJail) {
 			$this->unjailedRoot = $cache->getSourcePath($root);
@@ -42,6 +38,9 @@ class CacheJail extends CacheWrapper {
 		}
 	}
 
+	/**
+	 * @return string 
+	 */
 	protected function getRoot() {
 		return $this->root;
 	}
@@ -55,7 +54,10 @@ class CacheJail extends CacheWrapper {
 		return $this->unjailedRoot;
 	}
 
-	protected function getSourcePath($path) {
+	/**
+	 * @return string 
+	 */
+	protected function getSourcePath(string $path) {
 		if ($path === '') {
 			return $this->getRoot();
 		} else {
@@ -95,7 +97,7 @@ class CacheJail extends CacheWrapper {
 	/**
 	 * get the stored metadata of a file or folder
 	 *
-	 * @param string /int $file
+	 * @param string|int $file
 	 * @return ICacheEntry|false
 	 */
 	public function get($file) {
@@ -206,12 +208,12 @@ class CacheJail extends CacheWrapper {
 	/**
 	 * update the folder size and the size of all parent folders
 	 *
-	 * @param string|boolean $path
-	 * @param array $data (optional) meta data of the folder
+	 * @param array|ICacheEntry|null $data (optional) meta data of the folder
 	 */
-	public function correctFolderSize($path, $data = null, $isBackgroundScan = false) {
-		if ($this->getCache() instanceof Cache) {
-			$this->getCache()->correctFolderSize($this->getSourcePath($path), $data, $isBackgroundScan);
+	public function correctFolderSize(string $path, $data = null, bool $isBackgroundScan = false): void {
+		$cache = $this->getCache();
+		if ($cache instanceof Cache) {
+			$cache->correctFolderSize($this->getSourcePath($path), $data, $isBackgroundScan);
 		}
 	}
 
@@ -223,8 +225,9 @@ class CacheJail extends CacheWrapper {
 	 * @return int|float
 	 */
 	public function calculateFolderSize($path, $entry = null) {
-		if ($this->getCache() instanceof Cache) {
-			return $this->getCache()->calculateFolderSize($this->getSourcePath($path), $entry);
+		$cache = $this->getCache();
+		if ($cache instanceof Cache) {
+			return $cache->calculateFolderSize($this->getSourcePath($path), $entry);
 		} else {
 			return 0;
 		}
diff --git a/lib/private/Files/Cache/Wrapper/CacheWrapper.php b/lib/private/Files/Cache/Wrapper/CacheWrapper.php
index fdaa2cf4b7a..f2f1036d6a3 100644
--- a/lib/private/Files/Cache/Wrapper/CacheWrapper.php
+++ b/lib/private/Files/Cache/Wrapper/CacheWrapper.php
@@ -221,12 +221,12 @@ class CacheWrapper extends Cache {
 	/**
 	 * update the folder size and the size of all parent folders
 	 *
-	 * @param string|boolean $path
-	 * @param array $data (optional) meta data of the folder
+	 * @param array|ICacheEntry|null $data (optional) meta data of the folder
 	 */
-	public function correctFolderSize($path, $data = null, $isBackgroundScan = false) {
-		if ($this->getCache() instanceof Cache) {
-			$this->getCache()->correctFolderSize($path, $data, $isBackgroundScan);
+	public function correctFolderSize(string $path, $data = null, bool $isBackgroundScan = false): void {
+		$cache = $this->getCache();
+		if ($cache instanceof Cache) {
+			$cache->correctFolderSize($path, $data, $isBackgroundScan);
 		}
 	}
 
@@ -238,8 +238,9 @@ class CacheWrapper extends Cache {
 	 * @return int|float
 	 */
 	public function calculateFolderSize($path, $entry = null) {
-		if ($this->getCache() instanceof Cache) {
-			return $this->getCache()->calculateFolderSize($path, $entry);
+		$cache = $this->getCache();
+		if ($cache instanceof Cache) {
+			return $cache->calculateFolderSize($path, $entry);
 		} else {
 			return 0;
 		}