commit 739cc2cc9a563e5b4262dc1007e4b0977a4c7c36
author Edwin Wong <edwinwong@google.com> Wed Mar 10 20:12:36 2021 +0000
committer Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> Wed Mar 10 20:12:36 2021 +0000
tree 4849745949a3090a699611042e763902225da449
parent 107233b3ddf157b4a009faca90e9490bfa67aa6d
parent a6e551feef4e5faeec9ecc6b287eeade751e7f8b

[RESTRICT AUTOMERGE] Fix potential decrypt destPtr overflow. am: a6e551feef

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/13474212

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I43e854331e0b99158a81819a8541c05bcab5b358

drm/1.0/default/CryptoPlugin.cpp

diff --git a/drm/1.0/default/CryptoPlugin.cpp b/drm/1.0/default/CryptoPlugin.cpp
index e6d4e84..653708e 100644
--- a/drm/1.0/default/CryptoPlugin.cpp
+++ b/drm/1.0/default/CryptoPlugin.cpp
@@ -79,7 +79,7 @@
             }
         }
 
-        android::CryptoPlugin::Mode legacyMode;
+        android::CryptoPlugin::Mode legacyMode = android::CryptoPlugin::kMode_Unencrypted;
         switch(mode) {
         case Mode::UNENCRYPTED:
             legacyMode = android::CryptoPlugin::kMode_Unencrypted;
@@ -146,7 +146,10 @@
                 return Void();
             }
 
-            if (destBuffer.offset + destBuffer.size > destBase->getSize()) {
+            size_t totalDstSize = 0;
+            if (__builtin_add_overflow(destBuffer.offset, destBuffer.size, &totalDstSize) ||
+                totalDstSize > destBase->getSize()) {
+                android_errorWriteLog(0x534e4554, "176496353");
                 _hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "invalid buffer size");
                 return Void();
             }
@@ -157,7 +160,7 @@
             }
 
             base = static_cast<uint8_t *>(static_cast<void *>(destBase->getPointer()));
-            destPtr = static_cast<void *>(base + destination.nonsecureMemory.offset);
+            destPtr = static_cast<void*>(base + destination.nonsecureMemory.offset);
         } else if (destination.type == BufferType::NATIVE_HANDLE) {
             if (!secure) {
                 _hidl_cb(Status::BAD_VALUE, 0, "native handle destination must be secure");