I started typing a command into an .editorconfig file and as soon as I typed a comma "," devenv.exe suddenly started using 100% CPU on all of my processor cores.
I attached a CLRv4 debugger and saw a load of worker threads were stuck in System.Text.RegularExpressions.RegexInterpreter.Go via EditorConfig.EditorConfigDocument.ParseAsync.
(Updated) Steps to recreate
After some digging, I found out the _suppress regex can get stuck on certain inputs. Here's a reliable repro I've made in Linqpad 6:
// Copied from https://github.com/madskristensen/EditorConfigLanguage/blob/ebec9b5d3069c9c6a0adbdcf2e642ef2d9d8317f/src/Parser/EditorConfigDocumentParser.cs
Regex suppressRegex = new Regex(@"^(?<comment>#\s*suppress\s*):?\s*(?<errors>(\w{0,5}\s*)+)$", RegexOptions.IgnoreCase);
String goodLine = @"# Suppressed because we do use antiforgery tokens as configured in Startup.cs";
Match goodMatch = suppressRegex.Match( goodLine ); // Works fine
goodMatch.Dump();
String badLine = @"# Suppressed because we do use antiforgery tokens, as configured in Startup.cs";
Match badMatch = suppressRegex.Match( badLine ); // <-- Program will get stuck here.
badMatch.Dump();
I tried it on Regex101.com on the same input data and it reported a Catastrophic Backtracking error.
(Real-life) Steps to recreate
Have an editor config like this:
root = true
# All files
[*]
indent_style = tab
[*.csproj]
indent_style = space
indent_size = 2
# Code files
[*.cs]
indent_size = 4
insert_final_newline = true
charset = utf-8
# CA1055: URI return values should not be strings
dotnet_diagnostic.CA1055.severity = silent
# CA1056: URI properties should not be strings
dotnet_diagnostic.CA1056.severity = silent
# CA5395: Action method needs to specify the HTTP request kind explictly
# https://github.com/dotnet/aspnetcore/issues/33102
dotnet_diagnostic.CA5395.severity = none
# CA1707: Identifiers should not contain underscores
dotnet_diagnostic.CA1707.severity = none
# CA5391: Use antiforgery tokens in ASP.NET Core MVC controllers
dotnet_code_quality.CA5391.exclude_aspnet_core_mvc_controllerbase = true
Manually type a new comment line underneath the # CA5391 line (and before dotnet_code_quality.CA5391):
# Suppressed because we do use antiforgery tokens as configured in Startup.cs
Insert a comma after "tokens" and before "as configured":
# Suppressed because we do use antiforgery tokens, as configured in Startup.cs
devenv.exe will now hog your CPU.
Stack traces
> System.dll!System.Text.RegularExpressions.RegexInterpreter.Go() Unknown Non-user code. Skipped loading symbols.
System.dll!System.Text.RegularExpressions.RegexRunner.Scan(System.Text.RegularExpressions.Regex regex, string text, int textbeg, int textend, int textstart, int prevlen, bool quick = false, System.TimeSpan timeout) Unknown Non-user code. Skipped loading symbols.
System.dll!System.Text.RegularExpressions.Regex.Run(bool quick, int prevlen, string input, int beginning, int length, int startat) Unknown Non-user code. Skipped loading symbols.
System.dll!System.Text.RegularExpressions.Regex.Match(string input, int startat) Unknown Non-user code. Skipped loading symbols.
System.dll!System.Text.RegularExpressions.Regex.Match(string input) Unknown Non-user code. Skipped loading symbols.
EditorConfig.dll!EditorConfig.EditorConfigDocument.ParseAsync.AnonymousMethod__26_0() Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.Tasks.Task.InnerInvoke() Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.Tasks.Task.Execute() Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.Tasks.Task.ExecutionContextCallback(object obj) Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.Tasks.Task.ExecuteWithThreadLocal(ref System.Threading.Tasks.Task currentTaskSlot = Id = 1189516, Status = Running, Method = Inspecting the state of an object in the debuggee of type System.Delegate is not supported in this context.) Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.Tasks.Task.ExecuteEntry(bool bPreventDoubleExecution) Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.Tasks.Task.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem() Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading.ThreadPoolWorkQueue.Dispatch() Unknown Non-user code. Skipped loading symbols.
mscorlib.dll!System.Threading._ThreadPoolWaitCallback.PerformWaitCallback() Unknown Non-user code. Skipped loading symbols.
Installed product versions
Description
.editorconfigfile and as soon as I typed a comma ","devenv.exesuddenly started using 100% CPU on all of my processor cores.System.Text.RegularExpressions.RegexInterpreter.GoviaEditorConfig.EditorConfigDocument.ParseAsync.(Updated) Steps to recreate
After some digging, I found out the
_suppressregex can get stuck on certain inputs. Here's a reliable repro I've made in Linqpad 6:I tried it on Regex101.com on the same input data and it reported a Catastrophic Backtracking error.
(Real-life) Steps to recreate
Have an editor config like this:
Manually type a new comment line underneath the
# CA5391line (and beforedotnet_code_quality.CA5391):Insert a comma after "tokens" and before "as configured":
devenv.exewill now hog your CPU.Stack traces
and