From 2482aca7c32679339b2c79cb7f1d46234539a9ef Mon Sep 17 00:00:00 2001
From: Subv <subv2112@gmail.com>
Date: Mon, 30 Jul 2018 20:08:36 -0500
Subject: [PATCH] nvhost_ctrl_gpu: Only read the input parameters if they are
 actually there.

Passing nullptr to memcpy is undefined behavior.
---
 .../hle/service/nvdrv/devices/nvhost_ctrl_gpu.cpp  | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/core/hle/service/nvdrv/devices/nvhost_ctrl_gpu.cpp b/src/core/hle/service/nvdrv/devices/nvhost_ctrl_gpu.cpp
index 44e062f50..010072a5b 100644
--- a/src/core/hle/service/nvdrv/devices/nvhost_ctrl_gpu.cpp
+++ b/src/core/hle/service/nvdrv/devices/nvhost_ctrl_gpu.cpp
@@ -97,7 +97,9 @@ u32 nvhost_ctrl_gpu::GetTPCMasks(const std::vector<u8>& input, std::vector<u8>&
 u32 nvhost_ctrl_gpu::GetActiveSlotMask(const std::vector<u8>& input, std::vector<u8>& output) {
     LOG_DEBUG(Service_NVDRV, "called");
     IoctlActiveSlotMask params{};
-    std::memcpy(&params, input.data(), input.size());
+    if (input.size() > 0) {
+        std::memcpy(&params, input.data(), input.size());
+    }
     params.slot = 0x07;
     params.mask = 0x01;
     std::memcpy(output.data(), &params, output.size());
@@ -107,7 +109,9 @@ u32 nvhost_ctrl_gpu::GetActiveSlotMask(const std::vector<u8>& input, std::vector
 u32 nvhost_ctrl_gpu::ZCullGetCtxSize(const std::vector<u8>& input, std::vector<u8>& output) {
     LOG_DEBUG(Service_NVDRV, "called");
     IoctlZcullGetCtxSize params{};
-    std::memcpy(&params, input.data(), input.size());
+    if (input.size() > 0) {
+        std::memcpy(&params, input.data(), input.size());
+    }
     params.size = 0x1;
     std::memcpy(output.data(), &params, output.size());
     return 0;
@@ -116,7 +120,11 @@ u32 nvhost_ctrl_gpu::ZCullGetCtxSize(const std::vector<u8>& input, std::vector<u
 u32 nvhost_ctrl_gpu::ZCullGetInfo(const std::vector<u8>& input, std::vector<u8>& output) {
     LOG_DEBUG(Service_NVDRV, "called");
     IoctlNvgpuGpuZcullGetInfoArgs params{};
-    std::memcpy(&params, input.data(), input.size());
+
+    if (input.size() > 0) {
+        std::memcpy(&params, input.data(), input.size());
+    }
+
     params.width_align_pixels = 0x20;
     params.height_align_pixels = 0x20;
     params.pixel_squares_by_aliquots = 0x400;