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author | Andre Furtado <afurtado@google.com> | 2016-08-22 20:56:27 +0000 |
---|---|---|
committer | android-build-merger <android-build-merger@google.com> | 2016-08-22 20:56:27 +0000 |
commit | 20903846d562d78851c4b1b108efe3597450dead (patch) | |
tree | 4accdcf14f01515a1bab3a535e095bc99d5032a0 | |
parent | dbd812caac18a67329374a05136c57de9ad818e2 (diff) | |
parent | 53ff7691e0163f730ac9410da76e5ea61fe67343 (diff) | |
download | android_packages_providers_TelephonyProvider-20903846d562d78851c4b1b108efe3597450dead.tar.gz android_packages_providers_TelephonyProvider-20903846d562d78851c4b1b108efe3597450dead.tar.bz2 android_packages_providers_TelephonyProvider-20903846d562d78851c4b1b108efe3597450dead.zip |
30481342: Security Vulnerability - TOCTOU in MmsProvider allows access to files as phone (radio) uid - DO NOT MERGE
am: 53ff7691e0
Change-Id: Ibb6bf700c22e870c4351c7589fede41fe1f8146b
-rw-r--r-- | src/com/android/providers/telephony/MmsProvider.java | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/src/com/android/providers/telephony/MmsProvider.java b/src/com/android/providers/telephony/MmsProvider.java index 6b5b29e..329f505 100644 --- a/src/com/android/providers/telephony/MmsProvider.java +++ b/src/com/android/providers/telephony/MmsProvider.java @@ -16,6 +16,7 @@ package com.android.providers.telephony; +import android.annotation.NonNull; import android.app.AppOpsManager; import android.content.ContentProvider; import android.content.ContentValues; @@ -277,7 +278,11 @@ public class MmsProvider extends ContentProvider { @Override public Uri insert(Uri uri, ContentValues values) { - // Don't let anyone insert anything with the _data column + // The _data column is filled internally in MmsProvider, so this check is just to avoid + // it from being inadvertently set. This is not supposed to be a protection against + // malicious attack, since sql injection could still be attempted to bypass the check. On + // the other hand, the MmsProvider does verify that the _data column has an allowed value + // before opening any uri/files. if (values != null && values.containsKey(Part._DATA)) { return null; } @@ -702,9 +707,12 @@ public class MmsProvider extends ContentProvider { } @Override - public int update(Uri uri, ContentValues values, - String selection, String[] selectionArgs) { - // Don't let anyone update the _data column + public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { + // The _data column is filled internally in MmsProvider, so this check is just to avoid + // it from being inadvertently set. This is not supposed to be a protection against + // malicious attack, since sql injection could still be attempted to bypass the check. On + // the other hand, the MmsProvider does verify that the _data column has an allowed value + // before opening any uri/files. if (values != null && values.containsKey(Part._DATA)) { return 0; } @@ -810,7 +818,12 @@ public class MmsProvider extends ContentProvider { return null; } - // Verify that the _data path points to mms data + return safeOpenFileHelper(uri, mode); + } + + @NonNull + private ParcelFileDescriptor safeOpenFileHelper( + @NonNull Uri uri, @NonNull String mode) throws FileNotFoundException { Cursor c = query(uri, new String[]{"_data"}, null, null, null); int count = (c != null) ? c.getCount() : 0; if (count != 1) { @@ -831,10 +844,16 @@ public class MmsProvider extends ContentProvider { c.close(); if (path == null) { - return null; + throw new FileNotFoundException("Column _data not found."); } + + File filePath = new File(path); try { - File filePath = new File(path); + // The MmsProvider shouldn't open a file that isn't MMS data, so we verify that the + // _data path actually points to MMS data. That safeguards ourselves from callers who + // inserted or updated a URI (more specifically the _data column) with disallowed paths. + // TODO(afurtado): provide a more robust mechanism to avoid disallowed _data paths to + // be inserted/updated in the first place, including via SQL injection. if (!filePath.getCanonicalPath() .startsWith(getContext().getDir(PARTS_DIR_NAME, 0).getPath())) { Log.e(TAG, "openFile: path " @@ -842,7 +861,6 @@ public class MmsProvider extends ContentProvider { + " does not start with " + getContext().getDir(PARTS_DIR_NAME, 0).getPath()); // Don't care return value - filePath.delete(); return null; } } catch (IOException e) { @@ -850,7 +868,8 @@ public class MmsProvider extends ContentProvider { return null; } - return openFileHelper(uri, mode); + int modeBits = ParcelFileDescriptor.parseMode(mode); + return ParcelFileDescriptor.open(filePath, modeBits); } private void filterUnsupportedKeys(ContentValues values) { |