From 8bf4e0eaa5298e235d3606987736e5d4e6383fa8 Mon Sep 17 00:00:00 2001
From: Roman Nozdrin <rnozdrin@mariadb.com>
Date: Thu, 14 Apr 2022 11:53:09 +0000
Subject: [PATCH] MCOL-5050 EM Index dbroot container out-of-bound access
 checks doing EM deletes

---
 versioning/BRM/extentmap.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/versioning/BRM/extentmap.cpp b/versioning/BRM/extentmap.cpp
index 0f8d32a88..fab238286 100644
--- a/versioning/BRM/extentmap.cpp
+++ b/versioning/BRM/extentmap.cpp
@@ -527,12 +527,19 @@ ExtentMapIndexFindResult ExtentMapIndexImpl::search3dLayer(PartitionIndexContain
 void ExtentMapIndexImpl::deleteDbRoot(const DBRootT dbroot)
 {
   auto& extMapIndex = *get();
+  if (dbroot >= extMapIndex.size())
+    return;  // nothing to delete
   extMapIndex[dbroot].clear();
 }
 
 void ExtentMapIndexImpl::deleteOID(const DBRootT dbroot, const OID_t oid)
 {
   auto& extMapIndex = *get();
+  // nothing to delete
+  if (dbroot >= extMapIndex.size())
+    return;
+  if (extMapIndex[dbroot].empty())
+    return;
   auto oidsIter = extMapIndex[dbroot].find(oid);
   // Nothing to delete. Might be a sign of a problem.
   if (oidsIter == extMapIndex[dbroot].end())
@@ -544,6 +551,10 @@ void ExtentMapIndexImpl::deleteEMEntry(const EMEntry& emEntry, const ExtentMapId
 {
   // find partition
   auto& extMapIndex = *get();
+  if (emEntry.dbRoot >= extMapIndex.size())
+    return;
+  if (extMapIndex[emEntry.dbRoot].empty())
+    return;
   auto oidsIter = extMapIndex[emEntry.dbRoot].find(emEntry.fileID);
   if (oidsIter == extMapIndex[emEntry.dbRoot].end())
     return;
@@ -1646,7 +1657,6 @@ void ExtentMap::loadVersion4or5(T* in, bool upgradeV4ToV5)
     }
 
     growEMShmseg(nrows);
-    growEMIndexShmseg(ExtentMapIndexImpl::estimateEMIndexSize(emNumElements));
   }
 
   size_t progress = 0, writeSize = emNumElements * sizeof(EMEntry);