Fix StackOverflow in CfgAllPathValidator.AreAllSuccessorsValid

analyzers/src/SonarAnalyzer.CFG/Roslyn/CfgAllPathValidator.cs

@@ -23,29 +23,47 @@ namespace SonarAnalyzer.CFG.Roslyn
     public abstract class CfgAllPathValidator
     {
         private readonly ControlFlowGraph cfg;
-        private readonly Dictionary<BasicBlock, bool> visitedStatus = new Dictionary<BasicBlock, bool>();
+        private readonly HashSet<BasicBlock> visitedStatus = [];
 
         protected abstract bool IsValid(BasicBlock block);
         protected abstract bool IsInvalid(BasicBlock block);
 
         protected CfgAllPathValidator(ControlFlowGraph cfg) =>
             this.cfg = cfg;
 
-        public bool CheckAllPaths() =>
-            IsBlockOrAllSuccessorsValid(cfg.EntryBlock);
-
-        private bool IsBlockOrAllSuccessorsValid(BasicBlock block)
-        {
-            var isValid = !IsInvalid(block) && (IsValid(block) || AreAllSuccessorsValid(block));
-            visitedStatus[block] = isValid;
-            return isValid;
-        }
-
-        private bool AreAllSuccessorsValid(BasicBlock block)
+        public bool CheckAllPaths()
         {
-            visitedStatus[block] = true; // protects from loops, don't fail the computation if hits itself
-            return block.SuccessorBlocks.Any()
-                   && block.SuccessorBlocks.All(x => x != cfg.ExitBlock && (visitedStatus.ContainsKey(x) ? visitedStatus[x] : IsBlockOrAllSuccessorsValid(x)));
+            var blocks = new Stack<BasicBlock>();
+            blocks.Push(cfg.EntryBlock);
+            while (blocks.Count > 0)
+            {
+                var block = blocks.Pop();
+                if (IsInvalid(block))
+                {
+                    return false;
+                }
+                visitedStatus.Add(block); // protects from loops, don't fail the computation if hits itself
+                if (IsValid(block))
+                {
+                    continue;
+                }
+                if (block.SuccessorBlocks.IsEmpty)
+                {
+                    return false;
+                }
+                foreach (var successorBlock in block.SuccessorBlocks)
+                {
+                    if (successorBlock == cfg.ExitBlock)
+                    {
+                        return false;
+                    }
+                    if (!visitedStatus.Contains(successorBlock))
+                    {
+                        blocks.Push(successorBlock);
+                    }
+                }
+            }
+            return true;
         }
     }
 }

analyzers/tests/SonarAnalyzer.Net8.Test/Rules/InfiniteRecursion.cs

@@ -0,0 +1,35 @@
+/*
+ * SonarAnalyzer for .NET
+ * Copyright (C) 2015-2024 SonarSource SA
+ * mailto: contact AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+namespace SonarAnalyzer.Net8.Test.Rules;
+
+[TestClass]
+public class InfiniteRecursionTest
+{
+    private readonly VerifierBuilder roslynCfg = new VerifierBuilder<SonarAnalyzer.Rules.CSharp.InfiniteRecursion>()
+        .AddReferences(MetadataReferenceFacade.NetStandard21);
+
+    [TestMethod]
+    // see https://github.com/SonarSource/sonar-dotnet/issues/8977
+    public void InfiniteRecursion_RoslynCfg_8977() =>
+        roslynCfg.AddPaths("InfiniteRecursion_8977.cs")
+            .WithOptions(ParseOptionsHelper.FromCSharp8)
+            .Verify();
+}