Safeguard classpath/module-path against symlinks to identical entries

oldcwj · Sep 6, 2022 · 63e0b87 · 63e0b87
1 parent 96d195f
commit 63e0b87
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Showing 2 changed files with 13 additions and 4 deletions.
diff --git a/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java b/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java
@@ -35,7 +35,6 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
-import java.nio.file.LinkOption;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayDeque;
@@ -1444,7 +1443,7 @@ Path canonicalize(Path path, boolean strict) {
             absolutePath = absolutePath.getParent();
         }
         try {
-            Path realPath = absolutePath.toRealPath(LinkOption.NOFOLLOW_LINKS);
+            Path realPath = absolutePath.toRealPath();
             if (!Files.isReadable(realPath)) {
                 showError("Path entry " + ClasspathUtils.classpathToString(path) + " is not readable");
             }

diff --git a/...vm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageClassLoaderSupport.java b/...vm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageClassLoaderSupport.java
@@ -136,16 +136,18 @@ protected NativeImageClassLoaderSupport(ClassLoader defaultSystemClassLoader, St
         }
         buildcp = Arrays.stream(builderClassPathEntries)
                         .map(Path::of)
-                        .map(Path::toAbsolutePath)
+                        .map(Util::toRealPath)
                         .collect(Collectors.toUnmodifiableList());
 
         imagemp = Arrays.stream(modulePath)
                         .map(Path::of)
+                        .map(Util::toRealPath)
                         .collect(Collectors.toUnmodifiableList());
 
         buildmp = Optional.ofNullable(System.getProperty("jdk.module.path")).stream()
                         .flatMap(s -> Arrays.stream(s.split(File.pathSeparator)))
                         .map(Path::of)
+                        .map(Util::toRealPath)
                         .collect(Collectors.toUnmodifiableList());
 
         upgradeAndSystemModuleFinder = createUpgradeAndSystemModuleFinder();
@@ -216,13 +218,21 @@ static URL[] verifyClassPathAndConvertToURLs(String[] classpath) {
             Stream<Path> pathStream = new LinkedHashSet<>(Arrays.asList(classpath)).stream().flatMap(Util::toClassPathEntries);
             return pathStream.map(v -> {
                 try {
-                    return v.toAbsolutePath().toUri().toURL();
+                    return toRealPath(v).toUri().toURL();
                 } catch (MalformedURLException e) {
                     throw UserError.abort("Invalid classpath element '%s'. Make sure that all paths provided with '%s' are correct.", v, SubstrateOptions.IMAGE_CLASSPATH_PREFIX);
                 }
             }).toArray(URL[]::new);
         }
 
+        static Path toRealPath(Path p) {
+            try {
+                return p.toRealPath();
+            } catch (IOException e) {
+                throw UserError.abort("Path entry '%s' does not map to a real path.", p);
+            }
+        }
+
         static Stream<Path> toClassPathEntries(String classPathEntry) {
             Path entry = ClasspathUtils.stringToClasspath(classPathEntry);
             if (entry.endsWith(ClasspathUtils.cpWildcardSubstitute)) {