diff --git a/libs/ui/Android.bp b/libs/ui/Android.bp
index eb2e858..a2664f1 100644
--- a/libs/ui/Android.bp
+++ b/libs/ui/Android.bp
@@ -71,6 +71,7 @@
     shared_libs: [
         "android.hardware.graphics.allocator@2.0",
         "android.hardware.graphics.mapper@2.0",
+        "android.hardware.graphics.mapper@2.1",
         "android.hardware.configstore@1.0",
         "android.hardware.configstore-utils",
         "libbase",
diff --git a/libs/ui/Gralloc2.cpp b/libs/ui/Gralloc2.cpp
index 0eb08e5..1f746a2 100644
--- a/libs/ui/Gralloc2.cpp
+++ b/libs/ui/Gralloc2.cpp
@@ -39,9 +39,15 @@
 Mapper::Mapper()
 {
     mMapper = IMapper::getService();
-    if (mMapper == nullptr || mMapper->isRemote()) {
+    if (mMapper == nullptr) {
+        LOG_ALWAYS_FATAL("gralloc-mapper is missing");
+    }
+    if (mMapper->isRemote()) {
         LOG_ALWAYS_FATAL("gralloc-mapper must be in passthrough mode");
     }
+
+    // IMapper 2.1 is optional
+    mMapperV2_1 = hardware::graphics::mapper::V2_1::IMapper::castFrom(mMapper);
 }
 
 Error Mapper::createDescriptor(
@@ -91,6 +97,50 @@
             buffer, error);
 }
 
+Error Mapper::validateBufferSize(buffer_handle_t bufferHandle,
+        const IMapper::BufferDescriptorInfo& descriptorInfo,
+        uint32_t stride) const
+{
+    if (mMapperV2_1 == nullptr) {
+        return Error::NONE;
+    }
+
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+    auto ret = mMapperV2_1->validateBufferSize(buffer, descriptorInfo, stride);
+
+    return (ret.isOk()) ? static_cast<Error>(ret) : kTransactionError;
+}
+
+void Mapper::getTransportSize(buffer_handle_t bufferHandle,
+        uint32_t* outNumFds, uint32_t* outNumInts) const
+{
+    *outNumFds = uint32_t(bufferHandle->numFds);
+    *outNumInts = uint32_t(bufferHandle->numInts);
+
+    if (mMapperV2_1 == nullptr) {
+        return;
+    }
+
+    Error error;
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+    auto ret = mMapperV2_1->getTransportSize(buffer,
+            [&](const auto& tmpError, const auto& tmpNumFds, const auto& tmpNumInts) {
+                error = tmpError;
+                if (error != Error::NONE) {
+                    return;
+                }
+
+                *outNumFds = tmpNumFds;
+                *outNumInts = tmpNumInts;
+            });
+
+    if (!ret.isOk()) {
+        error = kTransactionError;
+    }
+    ALOGE_IF(error != Error::NONE, "getTransportSize(%p) failed with %d",
+            buffer, error);
+}
+
 Error Mapper::lock(buffer_handle_t bufferHandle, uint64_t usage,
         const IMapper::Rect& accessRegion,
         int acquireFence, void** outData) const
diff --git a/libs/ui/GraphicBuffer.cpp b/libs/ui/GraphicBuffer.cpp
index c880500..4ed2aa4 100644
--- a/libs/ui/GraphicBuffer.cpp
+++ b/libs/ui/GraphicBuffer.cpp
@@ -170,6 +170,8 @@
             inUsage, &handle, &outStride, mId,
             std::move(requestorName));
     if (err == NO_ERROR) {
+        mBufferMapper.getTransportSize(handle, &mTransportNumFds, &mTransportNumInts);
+
         width = static_cast<int>(inWidth);
         height = static_cast<int>(inHeight);
         format = inFormat;
@@ -199,7 +201,8 @@
 
     if (method == TAKE_UNREGISTERED_HANDLE || method == CLONE_HANDLE) {
         buffer_handle_t importedHandle;
-        status_t err = mBufferMapper.importBuffer(handle, &importedHandle);
+        status_t err = mBufferMapper.importBuffer(handle, width, height,
+                layerCount, format, usage, stride, &importedHandle);
         if (err != NO_ERROR) {
             initWithHandle(nullptr, WRAP_HANDLE, 0, 0, 0, 0, 0, 0);
 
@@ -212,6 +215,7 @@
         }
 
         handle = importedHandle;
+        mBufferMapper.getTransportSize(handle, &mTransportNumFds, &mTransportNumInts);
     }
 
     ANativeWindowBuffer::handle = handle;
@@ -323,11 +327,11 @@
 }
 
 size_t GraphicBuffer::getFlattenedSize() const {
-    return static_cast<size_t>(13 + (handle ? handle->numInts : 0)) * sizeof(int);
+    return static_cast<size_t>(13 + (handle ? mTransportNumInts : 0)) * sizeof(int);
 }
 
 size_t GraphicBuffer::getFdCount() const {
-    return static_cast<size_t>(handle ? handle->numFds : 0);
+    return static_cast<size_t>(handle ? mTransportNumFds : 0);
 }
 
 status_t GraphicBuffer::flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const {
@@ -353,18 +357,18 @@
     buf[12] = int(usage >> 32); // high 32-bits
 
     if (handle) {
-        buf[10] = handle->numFds;
-        buf[11] = handle->numInts;
-        memcpy(fds, handle->data, static_cast<size_t>(handle->numFds) * sizeof(int));
+        buf[10] = int32_t(mTransportNumFds);
+        buf[11] = int32_t(mTransportNumInts);
+        memcpy(fds, handle->data, static_cast<size_t>(mTransportNumFds) * sizeof(int));
         memcpy(buf + 13, handle->data + handle->numFds,
-                static_cast<size_t>(handle->numInts) * sizeof(int));
+                static_cast<size_t>(mTransportNumInts) * sizeof(int));
     }
 
     buffer = static_cast<void*>(static_cast<uint8_t*>(buffer) + sizeNeeded);
     size -= sizeNeeded;
     if (handle) {
-        fds += handle->numFds;
-        count -= static_cast<size_t>(handle->numFds);
+        fds += mTransportNumFds;
+        count -= static_cast<size_t>(mTransportNumFds);
     }
 
     return NO_ERROR;
@@ -457,7 +461,8 @@
 
     if (handle != 0) {
         buffer_handle_t importedHandle;
-        status_t err = mBufferMapper.importBuffer(handle, &importedHandle);
+        status_t err = mBufferMapper.importBuffer(handle, uint32_t(width), uint32_t(height),
+                uint32_t(layerCount), format, usage, uint32_t(stride), &importedHandle);
         if (err != NO_ERROR) {
             width = height = stride = format = usage_deprecated = 0;
             layerCount = 0;
@@ -470,6 +475,7 @@
         native_handle_close(handle);
         native_handle_delete(const_cast<native_handle_t*>(handle));
         handle = importedHandle;
+        mBufferMapper.getTransportSize(handle, &mTransportNumFds, &mTransportNumInts);
     }
 
     buffer = static_cast<void const*>(static_cast<uint8_t const*>(buffer) + sizeNeeded);
diff --git a/libs/ui/GraphicBufferMapper.cpp b/libs/ui/GraphicBufferMapper.cpp
index 1634328..672dc36 100644
--- a/libs/ui/GraphicBufferMapper.cpp
+++ b/libs/ui/GraphicBufferMapper.cpp
@@ -52,17 +52,42 @@
 }
 
 status_t GraphicBufferMapper::importBuffer(buffer_handle_t rawHandle,
+        uint32_t width, uint32_t height, uint32_t layerCount,
+        PixelFormat format, uint64_t usage, uint32_t stride,
         buffer_handle_t* outHandle)
 {
     ATRACE_CALL();
 
+    buffer_handle_t bufferHandle;
     Gralloc2::Error error = mMapper->importBuffer(
-            hardware::hidl_handle(rawHandle), outHandle);
+            hardware::hidl_handle(rawHandle), &bufferHandle);
+    if (error != Gralloc2::Error::NONE) {
+        ALOGW("importBuffer(%p) failed: %d", rawHandle, error);
+        return static_cast<status_t>(error);
+    }
 
-    ALOGW_IF(error != Gralloc2::Error::NONE, "importBuffer(%p) failed: %d",
-            rawHandle, error);
+    Gralloc2::IMapper::BufferDescriptorInfo info = {};
+    info.width = width;
+    info.height = height;
+    info.layerCount = layerCount;
+    info.format = static_cast<Gralloc2::PixelFormat>(format);
+    info.usage = usage;
+    error = mMapper->validateBufferSize(bufferHandle, info, stride);
+    if (error != Gralloc2::Error::NONE) {
+        ALOGE("validateBufferSize(%p) failed: %d", rawHandle, error);
+        freeBuffer(bufferHandle);
+        return static_cast<status_t>(error);
+    }
 
-    return static_cast<status_t>(error);
+    *outHandle = bufferHandle;
+
+    return NO_ERROR;
+}
+
+void GraphicBufferMapper::getTransportSize(buffer_handle_t handle,
+            uint32_t* outTransportNumFds, uint32_t* outTransportNumInts)
+{
+    mMapper->getTransportSize(handle, outTransportNumFds, outTransportNumInts);
 }
 
 status_t GraphicBufferMapper::freeBuffer(buffer_handle_t handle)
diff --git a/libs/ui/include/ui/Gralloc2.h b/libs/ui/include/ui/Gralloc2.h
index 8aee160..69c35f7 100644
--- a/libs/ui/include/ui/Gralloc2.h
+++ b/libs/ui/include/ui/Gralloc2.h
@@ -21,6 +21,7 @@
 
 #include <android/hardware/graphics/allocator/2.0/IAllocator.h>
 #include <android/hardware/graphics/mapper/2.0/IMapper.h>
+#include <android/hardware/graphics/mapper/2.1/IMapper.h>
 #include <utils/StrongPointer.h>
 
 namespace android {
@@ -55,6 +56,13 @@
 
     void freeBuffer(buffer_handle_t bufferHandle) const;
 
+    Error validateBufferSize(buffer_handle_t bufferHandle,
+            const IMapper::BufferDescriptorInfo& descriptorInfo,
+            uint32_t stride) const;
+
+    void getTransportSize(buffer_handle_t bufferHandle,
+            uint32_t* outNumFds, uint32_t* outNumInts) const;
+
     // The ownership of acquireFence is always transferred to the callee, even
     // on errors.
     Error lock(buffer_handle_t bufferHandle, uint64_t usage,
@@ -73,6 +81,7 @@
 
 private:
     sp<IMapper> mMapper;
+    sp<hardware::graphics::mapper::V2_1::IMapper> mMapperV2_1;
 };
 
 // A wrapper to IAllocator
diff --git a/libs/ui/include/ui/GraphicBuffer.h b/libs/ui/include/ui/GraphicBuffer.h
index 95c2d22..e794462 100644
--- a/libs/ui/include/ui/GraphicBuffer.h
+++ b/libs/ui/include/ui/GraphicBuffer.h
@@ -230,6 +230,10 @@
     GraphicBufferMapper& mBufferMapper;
     ssize_t mInitCheck;
 
+    // numbers of fds/ints in native_handle_t to flatten
+    uint32_t mTransportNumFds;
+    uint32_t mTransportNumInts;
+
     uint64_t mId;
 
     // Stores the generation number of this buffer. If this number does not
diff --git a/libs/ui/include/ui/GraphicBufferMapper.h b/libs/ui/include/ui/GraphicBufferMapper.h
index 06961b1..7cf003d 100644
--- a/libs/ui/include/ui/GraphicBufferMapper.h
+++ b/libs/ui/include/ui/GraphicBufferMapper.h
@@ -22,6 +22,7 @@
 
 #include <memory>
 
+#include <ui/PixelFormat.h>
 #include <utils/Singleton.h>
 
 
@@ -49,10 +50,15 @@
     // The imported outHandle must be freed with freeBuffer when no longer
     // needed. rawHandle is owned by the caller.
     status_t importBuffer(buffer_handle_t rawHandle,
+            uint32_t width, uint32_t height, uint32_t layerCount,
+            PixelFormat format, uint64_t usage, uint32_t stride,
             buffer_handle_t* outHandle);
 
     status_t freeBuffer(buffer_handle_t handle);
 
+    void getTransportSize(buffer_handle_t handle,
+            uint32_t* outTransportNumFds, uint32_t* outTransportNumInts);
+
     status_t lock(buffer_handle_t handle,
             uint32_t usage, const Rect& bounds, void** vaddr);