commit 91a4fcb311be53d47fd91ec1153186708f44ef1e
author Edwin Wong <edwinwong@google.com> Tue Apr 06 22:27:14 2021 +0000
committer Android (Google) Code Review <android-gerrit@google.com> Tue Apr 06 22:27:14 2021 +0000
tree e82aed813950737219efd84e0ae80eaf8a5bddb9
parent a6e551feef4e5faeec9ecc6b287eeade751e7f8b
parent 9fcd4886a3e1ccbc18acfadd84906400c9882eda

Merge "[RESTRICT AUTOMERGE] Fix CryptoPlugin use after free vulnerability." into qt-dev

drm/1.0/default/CryptoPlugin.cpp

diff --git a/drm/1.0/default/CryptoPlugin.cpp b/drm/1.0/default/CryptoPlugin.cpp
index dd519e6..d622117 100644
--- a/drm/1.0/default/CryptoPlugin.cpp
+++ b/drm/1.0/default/CryptoPlugin.cpp
@@ -126,7 +126,11 @@
             return Void();
         }
 
-        if (source.offset + offset + source.size > sourceBase->getSize()) {
+        size_t totalSize = 0;
+        if (__builtin_add_overflow(source.offset, offset, &totalSize) ||
+            __builtin_add_overflow(totalSize, source.size, &totalSize) ||
+            totalSize > sourceBase->getSize()) {
+            android_errorWriteLog(0x534e4554, "176496160");
             _hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "invalid buffer size");
             return Void();
         }
@@ -144,7 +148,10 @@
                 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();
             }
@@ -155,7 +162,7 @@
             }
 
             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");