File tomcat-8.0.53-CVE-2024-50379.patch of Package tomcat.37363
Index: apache-tomcat-8.0.53-src/java/org/apache/catalina/WebResourceLockSet.java
===================================================================
--- /dev/null
+++ apache-tomcat-8.0.53-src/java/org/apache/catalina/WebResourceLockSet.java
@@ -0,0 +1,73 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.catalina;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * Interface implemented by {@link WebResourceSet} implementations that wish to provide locking functionality.
+ */
+public interface WebResourceLockSet {
+
+ /**
+ * Lock the resource at the provided path for reading. The resource is not required to exist. Read locks are not
+ * exclusive.
+ *
+ * @param path The path to the resource to be locked for reading
+ *
+ * @return The {@link ResourceLock} that must be passed to {@link #unlockForRead(ResourceLock)} to release the lock
+ */
+ ResourceLock lockForRead(String path);
+
+ /**
+ * Release a read lock from the resource associated with the given {@link ResourceLock}.
+ *
+ * @param resourceLock The {@link ResourceLock} associated with the resource for which a read lock should be
+ * released
+ */
+ void unlockForRead(ResourceLock resourceLock);
+
+ /**
+ * Lock the resource at the provided path for writing. The resource is not required to exist. Write locks are
+ * exclusive.
+ *
+ * @param path The path to the resource to be locked for writing
+ *
+ * @return The {@link ResourceLock} that must be passed to {@link #unlockForWrite(ResourceLock)} to release the lock
+ */
+ ResourceLock lockForWrite(String path);
+
+ /**
+ * Release the write lock from the resource associated with the given {@link ResourceLock}.
+ *
+ * @param resourceLock The {@link ResourceLock} associated with the resource for which the write lock should be
+ * released
+ */
+ void unlockForWrite(ResourceLock resourceLock);
+
+
+ class ResourceLock {
+ public final AtomicInteger count = new AtomicInteger(0);
+ public final ReentrantReadWriteLock reentrantLock = new ReentrantReadWriteLock();
+ public final String key;
+
+ public ResourceLock(String key) {
+ this.key = key;
+ }
+ }
+}
Index: apache-tomcat-8.0.53-src/java/org/apache/catalina/webresources/DirResourceSet.java
===================================================================
--- apache-tomcat-8.0.53-src.orig/java/org/apache/catalina/webresources/DirResourceSet.java
+++ apache-tomcat-8.0.53-src/java/org/apache/catalina/webresources/DirResourceSet.java
@@ -22,24 +22,36 @@ import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
import java.util.Set;
import java.util.jar.Manifest;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.WebResource;
+import org.apache.catalina.WebResourceLockSet;
+import org.apache.catalina.WebResourceLockSet.ResourceLock;
import org.apache.catalina.WebResourceRoot;
import org.apache.catalina.WebResourceRoot.ResourceSetType;
import org.apache.catalina.util.ResourceSet;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.http.RequestUtil;
/**
* Represents a {@link org.apache.catalina.WebResourceSet} based on a directory.
*/
-public class DirResourceSet extends AbstractFileResourceSet {
+public class DirResourceSet extends AbstractFileResourceSet implements WebResourceLockSet {
private static final Log log = LogFactory.getLog(DirResourceSet.class);
+ private boolean caseSensitive = true;
+
+ private Map<String,ResourceLock> resourceLocksByPath = new HashMap<>();
+ private Object resourceLocksByPathLock = new Object();
+
+
/**
* A no argument constructor is required for this to work with the digester.
*/
@@ -98,22 +110,33 @@ public class DirResourceSet extends Abst
String webAppMount = getWebAppMount();
WebResourceRoot root = getRoot();
if (path.startsWith(webAppMount)) {
- File f = file(path.substring(webAppMount.length()), false);
- if (f == null) {
- return new EmptyResource(root, path);
- }
- if (!f.exists()) {
- return new EmptyResource(root, path, f);
- }
- if (f.isDirectory() && path.charAt(path.length() - 1) != '/') {
- path = path + '/';
+ /*
+ * Lock the path for reading until the WebResource has been constructed. The lock prevents concurrent reads
+ * and writes (e.g. HTTP GET and PUT / DELETE) for the same path causing corruption of the FileResource
+ * where some of the fields are set as if the file exists and some as set as if it does not.
+ */
+ ResourceLock lock = lockForRead(path);
+ try {
+ File f = file(path.substring(webAppMount.length()), false);
+ if (f == null) {
+ return new EmptyResource(root, path);
+ }
+ if (!f.exists()) {
+ return new EmptyResource(root, path, f);
+ }
+ if (f.isDirectory() && path.charAt(path.length() - 1) != '/') {
+ path = path + '/';
+ }
+ return new FileResource(root, path, f, isReadOnly(), getManifest(), this, lock.key);
+ } finally {
+ unlockForRead(lock);
}
- return new FileResource(root, path, f, isReadOnly(), getManifest());
} else {
return new EmptyResource(root, path);
}
}
+
@Override
public String[] list(String path) {
checkPath(path);
@@ -223,32 +246,42 @@ public class DirResourceSet extends Abst
return false;
}
- File dest = null;
String webAppMount = getWebAppMount();
- if (path.startsWith(webAppMount)) {
+ if (!path.startsWith(webAppMount)) {
+ return false;
+ }
+
+ File dest = null;
+ /*
+ * Lock the path for writing until the write is complete. The lock prevents concurrent reads and writes (e.g.
+ * HTTP GET and PUT / DELETE) for the same path causing corruption of the FileResource where some of the fields
+ * are set as if the file exists and some as set as if it does not.
+ */
+ ResourceLock lock = lockForWrite(path);
+ try {
dest = file(path.substring(webAppMount.length()), false);
if (dest == null) {
return false;
}
- } else {
- return false;
- }
- if (dest.exists() && !overwrite) {
- return false;
- }
+ if (dest.exists() && !overwrite) {
+ return false;
+ }
- try {
- if (overwrite) {
- Files.copy(is, dest.toPath(), StandardCopyOption.REPLACE_EXISTING);
- } else {
- Files.copy(is, dest.toPath());
+ try {
+ if (overwrite) {
+ Files.copy(is, dest.toPath(), StandardCopyOption.REPLACE_EXISTING);
+ } else {
+ Files.copy(is, dest.toPath());
+ }
+ } catch (IOException ioe) {
+ return false;
}
- } catch (IOException ioe) {
- return false;
- }
- return true;
+ return true;
+ } finally {
+ unlockForWrite(lock);
+ }
}
@Override
@@ -263,6 +296,7 @@ public class DirResourceSet extends Abst
@Override
protected void initInternal() throws LifecycleException {
super.initInternal();
+ caseSensitive = isCaseSensitive();
// Is this an exploded web application?
if (getWebAppMount().equals("")) {
// Look for a manifest
@@ -276,4 +310,116 @@ public class DirResourceSet extends Abst
}
}
}
+
+
+ /*
+ * Determines if this ResourceSet is based on a case sensitive file system or not.
+ */
+ private boolean isCaseSensitive() {
+ try {
+ String canonicalPath = getFileBase().getCanonicalPath();
+ File upper = new File(canonicalPath.toUpperCase(Locale.ENGLISH));
+ if (!canonicalPath.equals(upper.getCanonicalPath())) {
+ return true;
+ }
+ File lower = new File(canonicalPath.toLowerCase(Locale.ENGLISH));
+ if (!canonicalPath.equals(lower.getCanonicalPath())) {
+ return true;
+ }
+ /*
+ * Both upper and lower case versions of the current fileBase have the same canonical path so the file
+ * system must be case insensitive.
+ */
+ } catch (IOException ioe) {
+ log.warn(sm.getString("dirResourceSet.isCaseSensitive.fail", getFileBase().getAbsolutePath()), ioe);
+ }
+
+ return false;
+ }
+
+
+ private String getLockKey(String path) {
+ // Normalize path to ensure that the same key is used for the same path.
+ String normalisedPath = RequestUtil.normalize(path);
+ if (caseSensitive) {
+ return normalisedPath;
+ }
+ return normalisedPath.toLowerCase(Locale.ENGLISH);
+ }
+
+
+ @Override
+ public ResourceLock lockForRead(String path) {
+ String key = getLockKey(path);
+ ResourceLock resourceLock = null;
+ synchronized (resourceLocksByPathLock) {
+ /*
+ * Obtain the ResourceLock and increment the usage count inside the sync to ensure that that map always has
+ * a consistent view of the currently "in-use" ResourceLocks.
+ */
+ resourceLock = resourceLocksByPath.get(key);
+ if (resourceLock == null) {
+ resourceLock = new ResourceLock(key);
+ resourceLocksByPath.put(key, resourceLock);
+ }
+ resourceLock.count.incrementAndGet();
+ }
+ // Obtain the lock outside the sync as it will block if there is a current write lock.
+ resourceLock.reentrantLock.readLock().lock();
+ return resourceLock;
+ }
+
+
+ @Override
+ public void unlockForRead(ResourceLock resourceLock) {
+ // Unlock outside the sync as there is no need to do it inside.
+ resourceLock.reentrantLock.readLock().unlock();
+ synchronized (resourceLocksByPathLock) {
+ /*
+ * Decrement the usage count and remove ResourceLocks no longer required inside the sync to ensure that that
+ * map always has a consistent view of the currently "in-use" ResourceLocks.
+ */
+ if (resourceLock.count.decrementAndGet() == 0) {
+ resourceLocksByPath.remove(resourceLock.key);
+ }
+ }
+ }
+
+
+ @Override
+ public ResourceLock lockForWrite(String path) {
+ String key = getLockKey(path);
+ ResourceLock resourceLock = null;
+ synchronized (resourceLocksByPathLock) {
+ /*
+ * Obtain the ResourceLock and increment the usage count inside the sync to ensure that that map always has
+ * a consistent view of the currently "in-use" ResourceLocks.
+ */
+ resourceLock = resourceLocksByPath.get(key);
+ if (resourceLock == null) {
+ resourceLock = new ResourceLock(key);
+ resourceLocksByPath.put(key, resourceLock);
+ }
+ resourceLock.count.incrementAndGet();
+ }
+ // Obtain the lock outside the sync as it will block if there are any other current locks.
+ resourceLock.reentrantLock.writeLock().lock();
+ return resourceLock;
+ }
+
+
+ @Override
+ public void unlockForWrite(ResourceLock resourceLock) {
+ // Unlock outside the sync as there is no need to do it inside.
+ resourceLock.reentrantLock.writeLock().unlock();
+ synchronized (resourceLocksByPathLock) {
+ /*
+ * Decrement the usage count and remove ResourceLocks no longer required inside the sync to ensure that that
+ * map always has a consistent view of the currently "in-use" ResourceLocks.
+ */
+ if (resourceLock.count.decrementAndGet() == 0) {
+ resourceLocksByPath.remove(resourceLock.key);
+ }
+ }
+ }
}
Index: apache-tomcat-8.0.53-src/java/org/apache/catalina/webresources/FileResource.java
===================================================================
--- apache-tomcat-8.0.53-src.orig/java/org/apache/catalina/webresources/FileResource.java
+++ apache-tomcat-8.0.53-src/java/org/apache/catalina/webresources/FileResource.java
@@ -28,6 +28,8 @@ import java.nio.file.attribute.BasicFile
import java.security.cert.Certificate;
import java.util.jar.Manifest;
+import org.apache.catalina.WebResourceLockSet;
+import org.apache.catalina.WebResourceLockSet.ResourceLock;
import org.apache.catalina.WebResourceRoot;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
@@ -44,11 +46,19 @@ public class FileResource extends Abstra
private final String name;
private final boolean readOnly;
private final Manifest manifest;
+ private final WebResourceLockSet lockSet;
+ private final String lockKey;
- public FileResource(WebResourceRoot root, String webAppPath,
- File resource, boolean readOnly, Manifest manifest) {
+ public FileResource(WebResourceRoot root, String webAppPath, File resource, boolean readOnly, Manifest manifest) {
+ this(root, webAppPath, resource, readOnly, manifest, null, null);
+ }
+
+ public FileResource(WebResourceRoot root, String webAppPath, File resource, boolean readOnly, Manifest manifest,
+ WebResourceLockSet lockSet, String lockKey) {
super(root,webAppPath);
this.resource = resource;
+ this.lockSet = lockSet;
+ this.lockKey = lockKey;
if (webAppPath.charAt(webAppPath.length() - 1) == '/') {
String realName = resource.getName() + '/';
@@ -101,7 +111,22 @@ public class FileResource extends Abstra
if (readOnly) {
return false;
}
- return resource.delete();
+ /*
+ * Lock the path for writing until the delete is complete. The lock prevents concurrent reads and writes (e.g.
+ * HTTP GET and PUT / DELETE) for the same path causing corruption of the FileResource where some of the fields
+ * are set as if the file exists and some as set as if it does not.
+ */
+ ResourceLock lock = null;
+ if (lockSet != null) {
+ lock = lockSet.lockForWrite(lockKey);
+ }
+ try {
+ return resource.delete();
+ } finally {
+ if (lockSet != null) {
+ lockSet.unlockForWrite(lock);
+ }
+ }
}
@Override
Index: apache-tomcat-8.0.53-src/webapps/docs/changelog.xml
===================================================================
--- apache-tomcat-8.0.53-src.orig/webapps/docs/changelog.xml
+++ apache-tomcat-8.0.53-src/webapps/docs/changelog.xml
@@ -4745,6 +4745,10 @@
<bug>58004</bug>: Fix AJP buffering output data even in blocking mode.
(remm)
</fix>
+ <fix>
+ The previous fix for incosistent resource metadata during concurrent
+ reads and writes was incomplete. (markt)
+ </fix>
</changelog>
</subsection>
<subsection name="WebSocket">
