From 64cb0cf96de28bfd495e577b4dd46c26dbb6b197 Mon Sep 17 00:00:00 2001
From: Ben Tracy <ben.tracy@codeplay.com>
Date: Tue, 7 May 2024 11:03:53 +0100
Subject: [PATCH] [SYCL][Graph] Fix minor issues in graph update code (#13660)

- Check for empty cmd group when updating node reqs
- Fix nullptr deref in reqs check
---
 sycl/source/detail/graph_impl.cpp | 2 ++
 sycl/source/detail/graph_impl.hpp | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/sycl/source/detail/graph_impl.cpp b/sycl/source/detail/graph_impl.cpp
index 025fde4904a9..3da1864dd241 100644
--- a/sycl/source/detail/graph_impl.cpp
+++ b/sycl/source/detail/graph_impl.cpp
@@ -1281,6 +1281,8 @@ void exec_graph_impl::update(
   // Rebuild cached requirements for this graph with updated nodes
   MRequirements.clear();
   for (auto &Node : MNodeStorage) {
+    if (!Node->MCommandGroup)
+      continue;
     MRequirements.insert(MRequirements.end(),
                          Node->MCommandGroup->getRequirements().begin(),
                          Node->MCommandGroup->getRequirements().end());
diff --git a/sycl/source/detail/graph_impl.hpp b/sycl/source/detail/graph_impl.hpp
index a1057517c912..f9a7d1865834 100644
--- a/sycl/source/detail/graph_impl.hpp
+++ b/sycl/source/detail/graph_impl.hpp
@@ -181,6 +181,9 @@ class node_impl {
   /// @param IncomingReq Incoming requirement.
   /// @return True if a dependency is needed, false if not.
   bool hasRequirementDependency(sycl::detail::AccessorImplHost *IncomingReq) {
+    if (!MCommandGroup)
+      return false;
+
     access_mode InMode = IncomingReq->MAccessMode;
     switch (InMode) {
     case access_mode::read: