From 939980ec11b7d880814da936742d0653403e5a40 Mon Sep 17 00:00:00 2001
From: Norman Maurer <norman_maurer@apple.com>
Date: Thu, 13 Feb 2020 11:48:40 +0100
Subject: [PATCH] java.security.AccessControlException: access denied
 ("java.io.FilePermission" "/etc/os-release" "read") (#10018)

Motivation:

Modifications:

- Wrap the code and execute with an AccessController
- Ignore SecurityException (by just logging it)
- Add some more debug logging

Result:

Fixes https://github.com/netty/netty/issues/10017
---
 .../util/internal/PlatformDependent.java      | 82 +++++++++++--------
 1 file changed, 47 insertions(+), 35 deletions(-)

diff --git a/common/src/main/java/io/netty/util/internal/PlatformDependent.java b/common/src/main/java/io/netty/util/internal/PlatformDependent.java
index 85d6aaf593f..d830e9132df 100644
--- a/common/src/main/java/io/netty/util/internal/PlatformDependent.java
+++ b/common/src/main/java/io/netty/util/internal/PlatformDependent.java
@@ -49,7 +49,6 @@
 import java.util.Locale;
 import java.util.Queue;
 import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedDeque;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.regex.Matcher;
@@ -113,7 +112,10 @@ public final class PlatformDependent {
     private static final long DIRECT_MEMORY_LIMIT;
     private static final Cleaner CLEANER;
     private static final int UNINITIALIZED_ARRAY_ALLOCATION_THRESHOLD;
-
+    // For specifications, see https://www.freedesktop.org/software/systemd/man/os-release.html
+    private static final String[] OS_RELEASE_FILES = {"/etc/os-release", "/usr/lib/os-release"};
+    private static final String LINUX_ID_PREFIX = "ID=";
+    private static final String LINUX_ID_LIKE_PREFIX = "ID_LIKE=";
     public static final boolean BIG_ENDIAN_NATIVE_ORDER = ByteOrder.nativeOrder() == ByteOrder.BIG_ENDIAN;
 
     private static final Cleaner NOOP = buffer -> {
@@ -187,45 +189,55 @@ public final class PlatformDependent {
                     "instability.");
         }
 
-        // For specifications, see https://www.freedesktop.org/software/systemd/man/os-release.html
-        final String[] OS_RELEASE_FILES = {"/etc/os-release", "/usr/lib/os-release"};
-        final String LINUX_ID_PREFIX = "ID=";
-        final String LINUX_ID_LIKE_PREFIX = "ID_LIKE=";
-        Set<String> allowedClassifiers = new HashSet<String>(Arrays.asList(ALLOWED_LINUX_OS_CLASSIFIERS));
-        allowedClassifiers = Collections.unmodifiableSet(allowedClassifiers);
-        Set<String> availableClassifiers = new LinkedHashSet<String>();
-
-        for (String osReleaseFileName : OS_RELEASE_FILES) {
+        final Set<String> allowedClassifiers = Collections.unmodifiableSet(
+                new HashSet<String>(Arrays.asList(ALLOWED_LINUX_OS_CLASSIFIERS)));
+        final Set<String> availableClassifiers = new LinkedHashSet<String>();
+        for (final String osReleaseFileName : OS_RELEASE_FILES) {
             final File file = new File(osReleaseFileName);
-            if (file.exists()) {
-                BufferedReader reader = null;
+            boolean found = AccessController.doPrivileged((PrivilegedAction<Boolean>) () -> {
                 try {
-                    reader = new BufferedReader(
-                            new InputStreamReader(
-                                    new FileInputStream(file), CharsetUtil.UTF_8));
-
-                    String line;
-                    while ((line = reader.readLine()) != null) {
-                        if (line.startsWith(LINUX_ID_PREFIX)) {
-                            String id = normalizeOsReleaseVariableValue(line.substring(LINUX_ID_PREFIX.length()));
-                            addClassifier(allowedClassifiers, availableClassifiers, id);
-                        } else if (line.startsWith(LINUX_ID_LIKE_PREFIX)) {
-                            line = normalizeOsReleaseVariableValue(line.substring(LINUX_ID_LIKE_PREFIX.length()));
-                            addClassifier(allowedClassifiers, availableClassifiers, line.split("[ ]+"));
-                        }
-                    }
-                } catch (IOException ignored) {
-                    // Ignore
-                } finally {
-                    if (reader != null) {
+                    if (file.exists()) {
+                        BufferedReader reader = null;
                         try {
-                            reader.close();
-                        } catch (IOException ignored) {
-                            // Ignore
+                            reader = new BufferedReader(
+                                    new InputStreamReader(
+                                            new FileInputStream(file), CharsetUtil.UTF_8));
+
+                            String line;
+                            while ((line = reader.readLine()) != null) {
+                                if (line.startsWith(LINUX_ID_PREFIX)) {
+                                    String id = normalizeOsReleaseVariableValue(
+                                            line.substring(LINUX_ID_PREFIX.length()));
+                                    addClassifier(allowedClassifiers, availableClassifiers, id);
+                                } else if (line.startsWith(LINUX_ID_LIKE_PREFIX)) {
+                                    line = normalizeOsReleaseVariableValue(
+                                            line.substring(LINUX_ID_LIKE_PREFIX.length()));
+                                    addClassifier(allowedClassifiers, availableClassifiers, line.split("[ ]+"));
+                                }
+                            }
+                        } catch (SecurityException e) {
+                            logger.debug("Unable to read {}", osReleaseFileName, e);
+                        } catch (IOException e) {
+                            logger.debug("Error while reading content of {}", osReleaseFileName, e);
+                        } finally {
+                            if (reader != null) {
+                                try {
+                                    reader.close();
+                                } catch (IOException ignored) {
+                                    // Ignore
+                                }
+                            }
                         }
+                        // specification states we should only fall back if /etc/os-release does not exist
+                        return true;
                     }
+                } catch (SecurityException e) {
+                    logger.debug("Unable to check if {} exists", osReleaseFileName, e);
                 }
-                // specification states we should only fall back if /etc/os-release does not exist
+                return false;
+            });
+
+            if (found) {
                 break;
             }
         }