Merge "Fix security vulnerability in CryptoHal" into oc-dev am: 20e00b3f96

am: 9ac536d2ef

Change-Id: I15d0645e9ecf47dcd21d8d5005b24a67b34f92fb

1 files changed, 21 insertions, 4 deletions

diff --git a/drm/libmediadrm/CryptoHal.cpp b/drm/libmediadrm/CryptoHal.cpp
index 1fdc6e1954..5dd25639ca 100644
--- a/drm/libmediadrm/CryptoHal.cpp
+++ b/drm/libmediadrm/CryptoHal.cpp
@@ -240,11 +240,12 @@ int32_t CryptoHal::setHeapBase(const sp<IMemoryHeap>& heap) {
     Mutex::Autolock autoLock(mLock);
 
     int32_t seqNum = mHeapSeqNum++;
+
     int fd = heap->getHeapID();
     nativeHandle->data[0] = fd;
     auto hidlHandle = hidl_handle(nativeHandle);
     auto hidlMemory = hidl_memory("ashmem", hidlHandle, heap->getSize());
-    mHeapBases.add(seqNum, mNextBufferId);
+    mHeapBases.add(seqNum, HeapBase(mNextBufferId, heap->getSize()));
     Return<void> hResult = mPlugin->setSharedBufferBase(hidlMemory, mNextBufferId++);
     ALOGE_IF(!hResult.isOk(), "setSharedBufferBase(): remote call failed");
     return seqNum;
@@ -269,10 +270,26 @@ status_t CryptoHal::toSharedBuffer(const sp<IMemory>& memory, int32_t seqNum, ::
         return UNEXPECTED_NULL;
     }
 
-    // memory must be in the declared heap
-    CHECK(mHeapBases.indexOfKey(seqNum) >= 0);
+    // memory must be in one of the heaps that have been set
+    if (mHeapBases.indexOfKey(seqNum) < 0) {
+        return UNKNOWN_ERROR;
+    }
+
+    // heap must be the same size as the one that was set in setHeapBase
+    if (mHeapBases.valueFor(seqNum).getSize() != heap->getSize()) {
+        android_errorWriteLog(0x534e4554, "76221123");
+        return UNKNOWN_ERROR;
+     }
+
+    // memory must be within the address space of the heap
+    if (memory->pointer() != static_cast<uint8_t *>(heap->getBase()) + memory->offset()  ||
+            heap->getSize() < memory->offset() + memory->size() ||
+            SIZE_MAX - memory->offset() < memory->size()) {
+        android_errorWriteLog(0x534e4554, "76221123");
+        return UNKNOWN_ERROR;
+    }
 
-    buffer->bufferId = mHeapBases.valueFor(seqNum);
+    buffer->bufferId = mHeapBases.valueFor(seqNum).getBufferId();
     buffer->offset = offset >= 0 ? offset : 0;
     buffer->size = size;
     return OK;