Merge "SELinuxPolicyInstallReceiver: Prevent partial or mixed policy updates."
diff --git a/services/core/java/com/android/server/updates/SELinuxPolicyInstallReceiver.java b/services/core/java/com/android/server/updates/SELinuxPolicyInstallReceiver.java
index 24318df..04774d4 100644
--- a/services/core/java/com/android/server/updates/SELinuxPolicyInstallReceiver.java
+++ b/services/core/java/com/android/server/updates/SELinuxPolicyInstallReceiver.java
@@ -48,39 +48,6 @@
super("/data/security/bundle", "sepolicy_bundle", "metadata/", "version");
}
- private void backupContexts(File contexts) {
- new File(contexts, versionPath).renameTo(
- new File(contexts, versionPath + "_backup"));
-
- new File(contexts, macPermissionsPath).renameTo(
- new File(contexts, macPermissionsPath + "_backup"));
-
- new File(contexts, seappContextsPath).renameTo(
- new File(contexts, seappContextsPath + "_backup"));
-
- new File(contexts, propertyContextsPath).renameTo(
- new File(contexts, propertyContextsPath + "_backup"));
-
- new File(contexts, fileContextsPath).renameTo(
- new File(contexts, fileContextsPath + "_backup"));
-
- new File(contexts, sepolicyPath).renameTo(
- new File(contexts, sepolicyPath + "_backup"));
-
- new File(contexts, serviceContextsPath).renameTo(
- new File(contexts, serviceContextsPath + "_backup"));
- }
-
- private void copyUpdate(File contexts) {
- new File(updateDir, versionPath).renameTo(new File(contexts, versionPath));
- new File(updateDir, macPermissionsPath).renameTo(new File(contexts, macPermissionsPath));
- new File(updateDir, seappContextsPath).renameTo(new File(contexts, seappContextsPath));
- new File(updateDir, propertyContextsPath).renameTo(new File(contexts, propertyContextsPath));
- new File(updateDir, fileContextsPath).renameTo(new File(contexts, fileContextsPath));
- new File(updateDir, sepolicyPath).renameTo(new File(contexts, sepolicyPath));
- new File(updateDir, serviceContextsPath).renameTo(new File(contexts, serviceContextsPath));
- }
-
private int readInt(BufferedInputStream reader) throws IOException {
int value = 0;
for (int i=0; i < 4; i++) {
@@ -108,17 +75,27 @@
writeUpdate(updateDir, destination, Base64.decode(chunk, Base64.DEFAULT));
}
+ private void deleteRecursive(File fileOrDirectory) {
+ if (fileOrDirectory.isDirectory())
+ for (File child : fileOrDirectory.listFiles())
+ deleteRecursive(child);
+ fileOrDirectory.delete();
+ }
+
private void unpackBundle() throws IOException {
BufferedInputStream stream = new BufferedInputStream(new FileInputStream(updateContent));
+ File tmp = new File(updateDir.getParentFile(), "tmp");
try {
int[] chunkLengths = readChunkLengths(stream);
- installFile(new File(updateDir, versionPath), stream, chunkLengths[0]);
- installFile(new File(updateDir, macPermissionsPath), stream, chunkLengths[1]);
- installFile(new File(updateDir, seappContextsPath), stream, chunkLengths[2]);
- installFile(new File(updateDir, propertyContextsPath), stream, chunkLengths[3]);
- installFile(new File(updateDir, fileContextsPath), stream, chunkLengths[4]);
- installFile(new File(updateDir, sepolicyPath), stream, chunkLengths[5]);
- installFile(new File(updateDir, serviceContextsPath), stream, chunkLengths[6]);
+ deleteRecursive(tmp);
+ tmp.mkdirs();
+ installFile(new File(tmp, versionPath), stream, chunkLengths[0]);
+ installFile(new File(tmp, macPermissionsPath), stream, chunkLengths[1]);
+ installFile(new File(tmp, seappContextsPath), stream, chunkLengths[2]);
+ installFile(new File(tmp, propertyContextsPath), stream, chunkLengths[3]);
+ installFile(new File(tmp, fileContextsPath), stream, chunkLengths[4]);
+ installFile(new File(tmp, sepolicyPath), stream, chunkLengths[5]);
+ installFile(new File(tmp, serviceContextsPath), stream, chunkLengths[6]);
} finally {
IoUtils.closeQuietly(stream);
}
@@ -126,22 +103,22 @@
private void applyUpdate() throws IOException, ErrnoException {
Slog.i(TAG, "Applying SELinux policy");
- File contexts = new File(updateDir.getParentFile(), "contexts");
+ File backup = new File(updateDir.getParentFile(), "backup");
File current = new File(updateDir.getParentFile(), "current");
- File update = new File(updateDir.getParentFile(), "update");
File tmp = new File(updateDir.getParentFile(), "tmp");
if (current.exists()) {
- Os.symlink(updateDir.getPath(), update.getPath());
- Os.rename(update.getPath(), current.getPath());
- } else {
- Os.symlink(updateDir.getPath(), current.getPath());
+ deleteRecursive(backup);
+ Os.rename(current.getPath(), backup.getPath());
}
- contexts.mkdirs();
- backupContexts(contexts);
- copyUpdate(contexts);
- Os.symlink(contexts.getPath(), tmp.getPath());
- Os.rename(tmp.getPath(), current.getPath());
- SystemProperties.set("selinux.reload_policy", "1");
+ try {
+ Os.rename(tmp.getPath(), current.getPath());
+ SystemProperties.set("selinux.reload_policy", "1");
+ } catch (ErrnoException e) {
+ Slog.e(TAG, "Could not update selinux policy: ", e);
+ if (backup.exists()) {
+ Os.rename(backup.getPath(), current.getPath());
+ }
+ }
}
@Override