From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aishwarya Mallampati <amallampati@google.com>
Date: Wed, 10 May 2023 21:54:43 +0000
Subject: [PATCH] Update file permissions using canonical path

Bug: 264880895
Bug: 264880689
Test: atest android.telephonyprovider.cts.MmsPartTest
      atest CtsTelephonyTestCases
      Sanity check - sending and receiving sms and mms manually
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:6743638a096c32627f398efd2ea78f08b8a2db8c)
Merged-In: I8dd888ea31ec07c9f0de38eb8e8170d3ed255686
Change-Id: I8dd888ea31ec07c9f0de38eb8e8170d3ed255686
---
 src/com/android/providers/telephony/MmsProvider.java | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/com/android/providers/telephony/MmsProvider.java b/src/com/android/providers/telephony/MmsProvider.java
index 6ba775ba..7546c246 100644
--- a/src/com/android/providers/telephony/MmsProvider.java
+++ b/src/com/android/providers/telephony/MmsProvider.java
@@ -819,15 +819,16 @@ public class MmsProvider extends ContentProvider {
                 String path = getContext().getDir(PARTS_DIR_NAME, 0).getPath() + '/' +
                         uri.getPathSegments().get(1);
                 try {
+                    File canonicalFile = new File(path).getCanonicalFile();
                     String partsDirPath = getContext().getDir(PARTS_DIR_NAME, 0).getCanonicalPath();
-                    if (!new File(path).getCanonicalPath().startsWith(partsDirPath)) {
+                    if (!canonicalFile.getPath().startsWith(partsDirPath + '/')) {
                         EventLog.writeEvent(0x534e4554, "240685104",
                                 Binder.getCallingUid(), (TAG + " update: path " + path +
                                         " does not start with " + partsDirPath));
                         return 0;
                     }
                     // Reset the file permission back to read for everyone but me.
-                    Os.chmod(path, 0644);
+                    Os.chmod(canonicalFile.getPath(), 0644);
                     if (LOCAL_LOGV) {
                         Log.d(TAG, "MmsProvider.update chmod is successful for path: " + path);
                     }
