From 2f1389233e1eefbecf7703177b6f28248fcedc87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Wed, 13 Dec 2023 21:53:16 +0100
Subject: [PATCH] MemBlockInfo: Fix potential out-of-bounds in the slab map,
 reported by Nemoumbra

---
 Core/Debugger/MemBlockInfo.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Core/Debugger/MemBlockInfo.cpp b/Core/Debugger/MemBlockInfo.cpp
index f727d3a484..0f6be382bf 100644
--- a/Core/Debugger/MemBlockInfo.cpp
+++ b/Core/Debugger/MemBlockInfo.cpp
@@ -288,7 +288,12 @@ void MemSlabMap::Clear() {
 
 MemSlabMap::Slab *MemSlabMap::FindSlab(uint32_t addr) {
 	// Jump ahead using our index.
-	Slab *slab = heads_[addr / SLICE_SIZE];
+	size_t slabIndex = addr / SLICE_SIZE;
+	if (slabIndex >= heads_.size()) {
+		// Shouldn't happen, but apparently can.
+		return nullptr;
+	}
+	Slab *slab = heads_[slabIndex];
 	// We often move forward, so check the last find.
 	if (lastFind_->start > slab->start && lastFind_->start <= addr)
 		slab = lastFind_;