Improve visibility of IMemory security risks
This change renames the IMemory raw pointer accessors to
unsecure*() to make it apparent to coders and code reviewers
that the returned buffer may potentially be shared with
untrusted processes, who may, after the fact, attempt to
read and/or modify the contents. This may lead to hard to
find security bugs and hopefully the rename makes it harder
to forget.
The change also attempts to fix all the callsites to make
everything build correctly, but in the processes, wherever the
callsite code was not obviously secure, I added a TODO requesting
the owners to either document why it's secure or to change the
code. Apologies in advance to the owners if there are some false
positives here - I don't have enough context to reason about all
the different callsites.
Test: Completely syntactic change. Made sure code still builds.
Change-Id: I5fb99aa797c488406083178a6b05355d98710d3b
diff --git a/services/camera/libcameraservice/api1/CameraClient.cpp b/services/camera/libcameraservice/api1/CameraClient.cpp
index 764b3a9..388a5dc 100644
--- a/services/camera/libcameraservice/api1/CameraClient.cpp
+++ b/services/camera/libcameraservice/api1/CameraClient.cpp
@@ -534,7 +534,7 @@
}
if (mHardware != nullptr) {
- VideoNativeHandleMetadata *metadata = (VideoNativeHandleMetadata*)(dataPtr->pointer());
+ VideoNativeHandleMetadata *metadata = (VideoNativeHandleMetadata*)(dataPtr->unsecurePointer());
metadata->eType = kMetadataBufferTypeNativeHandleSource;
metadata->pHandle = handle;
mHardware->releaseRecordingFrame(dataPtr);
@@ -573,7 +573,7 @@
}
if (!disconnected) {
- VideoNativeHandleMetadata *metadata = (VideoNativeHandleMetadata*)(dataPtr->pointer());
+ VideoNativeHandleMetadata *metadata = (VideoNativeHandleMetadata*)(dataPtr->unsecurePointer());
metadata->eType = kMetadataBufferTypeNativeHandleSource;
metadata->pHandle = handle;
frames.push_back(dataPtr);
@@ -916,8 +916,12 @@
ALOGE("%s: dataPtr does not contain VideoNativeHandleMetadata!", __FUNCTION__);
return;
}
+ // TODO: Using unsecurePointer() has some associated security pitfalls
+ // (see declaration for details).
+ // Either document why it is safe in this case or address the
+ // issue (e.g. by copying).
VideoNativeHandleMetadata *metadata =
- (VideoNativeHandleMetadata*)(msg.dataPtr->pointer());
+ (VideoNativeHandleMetadata*)(msg.dataPtr->unsecurePointer());
if (metadata->eType == kMetadataBufferTypeNativeHandleSource) {
handle = metadata->pHandle;
}
@@ -1073,8 +1077,12 @@
// Check if dataPtr contains a VideoNativeHandleMetadata.
if (dataPtr->size() == sizeof(VideoNativeHandleMetadata)) {
+ // TODO: Using unsecurePointer() has some associated security pitfalls
+ // (see declaration for details).
+ // Either document why it is safe in this case or address the
+ // issue (e.g. by copying).
VideoNativeHandleMetadata *metadata =
- (VideoNativeHandleMetadata*)(dataPtr->pointer());
+ (VideoNativeHandleMetadata*)(dataPtr->unsecurePointer());
if (metadata->eType == kMetadataBufferTypeNativeHandleSource) {
handle = metadata->pHandle;
}
diff --git a/services/camera/libcameraservice/device1/CameraHardwareInterface.cpp b/services/camera/libcameraservice/device1/CameraHardwareInterface.cpp
index 522d521..62ef681 100644
--- a/services/camera/libcameraservice/device1/CameraHardwareInterface.cpp
+++ b/services/camera/libcameraservice/device1/CameraHardwareInterface.cpp
@@ -165,8 +165,12 @@
mem = mHidlMemPoolMap.at(data);
}
sp<CameraHeapMemory> heapMem(static_cast<CameraHeapMemory *>(mem->handle));
+ // TODO: Using unsecurePointer() has some associated security pitfalls
+ // (see declaration for details).
+ // Either document why it is safe in this case or address the
+ // issue (e.g. by copying).
VideoNativeHandleMetadata* md = (VideoNativeHandleMetadata*)
- heapMem->mBuffers[bufferIndex]->pointer();
+ heapMem->mBuffers[bufferIndex]->unsecurePointer();
md->pHandle = const_cast<native_handle_t*>(frameData.getNativeHandle());
sDataCbTimestamp(timestamp, (int32_t) msgType, mem, bufferIndex, this);
return hardware::Void();
@@ -192,8 +196,12 @@
hidl_msg.bufferIndex, mem->mNumBufs);
return hardware::Void();
}
+ // TODO: Using unsecurePointer() has some associated security pitfalls
+ // (see declaration for details).
+ // Either document why it is safe in this case or address the
+ // issue (e.g. by copying).
VideoNativeHandleMetadata* md = (VideoNativeHandleMetadata*)
- mem->mBuffers[hidl_msg.bufferIndex]->pointer();
+ mem->mBuffers[hidl_msg.bufferIndex]->unsecurePointer();
md->pHandle = const_cast<native_handle_t*>(hidl_msg.frameData.getNativeHandle());
msgs.push_back({hidl_msg.timestamp, mem->mBuffers[hidl_msg.bufferIndex]});
@@ -578,7 +586,11 @@
int bufferIndex = offset / size;
if (CC_LIKELY(mHidlDevice != nullptr)) {
if (size == sizeof(VideoNativeHandleMetadata)) {
- VideoNativeHandleMetadata* md = (VideoNativeHandleMetadata*) mem->pointer();
+ // TODO: Using unsecurePointer() has some associated security pitfalls
+ // (see declaration for details).
+ // Either document why it is safe in this case or address the
+ // issue (e.g. by copying).
+ VideoNativeHandleMetadata* md = (VideoNativeHandleMetadata*) mem->unsecurePointer();
// Caching the handle here because md->pHandle will be subject to HAL's edit
native_handle_t* nh = md->pHandle;
hidl_handle frame = nh;
@@ -605,7 +617,11 @@
if (size == sizeof(VideoNativeHandleMetadata)) {
uint32_t heapId = heap->getHeapID();
uint32_t bufferIndex = offset / size;
- VideoNativeHandleMetadata* md = (VideoNativeHandleMetadata*) mem->pointer();
+ // TODO: Using unsecurePointer() has some associated security pitfalls
+ // (see declaration for details).
+ // Either document why it is safe in this case or address the
+ // issue (e.g. by copying).
+ VideoNativeHandleMetadata* md = (VideoNativeHandleMetadata*) mem->unsecurePointer();
// Caching the handle here because md->pHandle will be subject to HAL's edit
native_handle_t* nh = md->pHandle;
VideoFrameMessage msg;