prevent cross-process write to profile file

Author: isra-fel

src/Accounts/Authentication.ResourceManager/ProtectedFileProvider.cs

@@ -36,13 +36,18 @@ public abstract class ProtectedFileProvider : IFileProvider, IDisposable
         public const int MaxTries = 30;
         static readonly TimeSpan RetryInterval = TimeSpan.FromMilliseconds(500);
         protected Stream _stream;
-        object _initializationLock = new object();
+
+        /// <summary>
+        /// Use a Mutex to prevent cross-process file I/O
+        /// </summary>
+        /// <returns></returns>
+        private static readonly Mutex _initializationLock = new Mutex(false, @"Global\AzurePowerShellProtectedFileProviderInit");
         public string FilePath { get; set; }
 
         protected IDataStore DataStore { get; set; }
 
         /// <summary>
-        /// 
+        ///
         /// </summary>
         public Stream Stream
         {
@@ -87,18 +92,17 @@ public StreamWriter CreateWriter()
 
         protected virtual void InitializeStream()
         {
-            lock (_initializationLock)
+            _initializationLock.WaitOne();
+            if (_stream == null)
             {
-                if (_stream == null)
+                Stream stream;
+                if (!TryGetStreamLock(AcquireLock, FilePath, out stream))
                 {
-                    Stream stream;
-                    if (!TryGetStreamLock(AcquireLock, FilePath, out stream))
-                    {
-                        throw new UnauthorizedAccessException(string.Format(Resources.FileLockFailure, FilePath));
-                    }
-
-                    _stream = stream;
+                    _initializationLock.ReleaseMutex();
+                    throw new UnauthorizedAccessException(string.Format(Resources.FileLockFailure, FilePath));
                 }
+                _initializationLock.ReleaseMutex();
+                _stream = stream;
             }
         }