lib - Add DispatchGetEventInformationLength to ensure we send at least EVENT_INFORMATION buffer size.

Author: Liryna

dokan/cleanup.c

@@ -26,7 +26,7 @@ VOID DispatchCleanup(HANDLE Handle, PEVENT_CONTEXT EventContext,
   PEVENT_INFORMATION eventInfo;
   DOKAN_FILE_INFO fileInfo;
   PDOKAN_OPEN_INFO openInfo;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION);
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(0);
 
   CheckFileName(EventContext->Operation.Cleanup.FileName);
 

dokan/close.c

@@ -26,7 +26,7 @@ VOID DispatchClose(HANDLE Handle, PEVENT_CONTEXT EventContext,
   PEVENT_INFORMATION eventInfo;
   DOKAN_FILE_INFO fileInfo;
   PDOKAN_OPEN_INFO openInfo;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION);
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(0);
 
   UNREFERENCED_PARAMETER(Handle);
 

dokan/directory.c

@@ -525,10 +525,9 @@ VOID DispatchDirectoryInformation(HANDLE Handle, PEVENT_CONTEXT EventContext,
   PDOKAN_OPEN_INFO openInfo;
   NTSTATUS status = STATUS_SUCCESS;
   ULONG fileInfoClass = EventContext->Operation.Directory.FileInformationClass;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION) - 8 +
-                          EventContext->Operation.Directory.BufferLength;
-
   BOOLEAN patternCheck = TRUE;
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(
+      EventContext->Operation.Directory.BufferLength);
 
   CheckFileName(EventContext->Operation.Directory.DirectoryName);
 

dokan/dokan.c

@@ -570,6 +570,14 @@ VOID CheckFileName(LPWSTR FileName) {
     FileName[len - 1] = '\0';
 }
 
+ULONG DispatchGetEventInformationLength(ULONG bufferSize) {
+  // EVENT_INFORMATION has a buffer of size 8 already
+  // we remote it to the struct size and add the requested buffer size
+  // but we need at least to have enough space to set EVENT_INFORMATION
+  return max((ULONG)sizeof(EVENT_INFORMATION),
+             sizeof(EVENT_INFORMATION) - 8 + bufferSize);
+}
+
 PEVENT_INFORMATION
 DispatchCommon(PEVENT_CONTEXT EventContext, ULONG SizeOfEventInfo,
                PDOKAN_INSTANCE DokanInstance, PDOKAN_FILE_INFO DokanFileInfo,

dokan/dokani.h

@@ -119,6 +119,8 @@ BOOL IsMountPointDriveLetter(LPCWSTR mountPoint);
 VOID SendEventInformation(HANDLE Handle, PEVENT_INFORMATION EventInfo,
                           ULONG EventLength, PDOKAN_INSTANCE DokanInstance);
 
+ULONG DispatchGetEventInformationLength(ULONG bufferSize);
+
 PEVENT_INFORMATION
 DispatchCommon(PEVENT_CONTEXT EventContext, ULONG SizeOfEventInfo,
                PDOKAN_INSTANCE DokanInstance, PDOKAN_FILE_INFO DokanFileInfo,

dokan/fileinfo.c

@@ -419,10 +419,8 @@ VOID DispatchQueryInformation(HANDLE Handle, PEVENT_CONTEXT EventContext,
   ULONG remainingLength;
   NTSTATUS status = STATUS_INVALID_PARAMETER;
   PDOKAN_OPEN_INFO openInfo;
-  ULONG sizeOfEventInfo;
-
-  sizeOfEventInfo =
-      sizeof(EVENT_INFORMATION) - 8 + EventContext->Operation.File.BufferLength;
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(
+      EventContext->Operation.File.BufferLength);
 
   CheckFileName(EventContext->Operation.File.FileName);
 

dokan/flush.c

@@ -25,9 +25,9 @@ VOID DispatchFlush(HANDLE Handle, PEVENT_CONTEXT EventContext,
                    PDOKAN_INSTANCE DokanInstance) {
   DOKAN_FILE_INFO fileInfo;
   PEVENT_INFORMATION eventInfo;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION);
   PDOKAN_OPEN_INFO openInfo;
   NTSTATUS status;
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(0);
 
   CheckFileName(EventContext->Operation.Flush.FileName);
 

dokan/lock.c

@@ -26,9 +26,9 @@ VOID DispatchLock(HANDLE Handle, PEVENT_CONTEXT EventContext,
                   PDOKAN_INSTANCE DokanInstance) {
   DOKAN_FILE_INFO fileInfo;
   PEVENT_INFORMATION eventInfo;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION);
   PDOKAN_OPEN_INFO openInfo;
   NTSTATUS status;
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(0);
 
   CheckFileName(EventContext->Operation.Lock.FileName);
 

dokan/read.c

@@ -28,10 +28,8 @@ VOID DispatchRead(HANDLE Handle, PEVENT_CONTEXT EventContext,
   ULONG readLength = 0;
   NTSTATUS status = STATUS_NOT_IMPLEMENTED;
   DOKAN_FILE_INFO fileInfo;
-  ULONG sizeOfEventInfo;
-
-  sizeOfEventInfo =
-      sizeof(EVENT_INFORMATION) - 8 + EventContext->Operation.Read.BufferLength;
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(
+      EventContext->Operation.Read.BufferLength);
 
   CheckFileName(EventContext->Operation.Read.FileName);
 

dokan/security.c

@@ -131,12 +131,11 @@ VOID DispatchQuerySecurity(HANDLE Handle, PEVENT_CONTEXT EventContext,
   PEVENT_INFORMATION eventInfo;
   DOKAN_FILE_INFO fileInfo;
   PDOKAN_OPEN_INFO openInfo;
-  ULONG eventInfoLength;
   NTSTATUS status = STATUS_NOT_IMPLEMENTED;
   ULONG lengthNeeded = 0;
+  ULONG eventInfoLength = DispatchGetEventInformationLength(
+      EventContext->Operation.Security.BufferLength);
 
-  eventInfoLength = sizeof(EVENT_INFORMATION) - 8 +
-                    EventContext->Operation.Security.BufferLength;
   CheckFileName(EventContext->Operation.Security.FileName);
 
   eventInfo = DispatchCommon(EventContext, eventInfoLength, DokanInstance,
@@ -184,11 +183,10 @@ VOID DispatchSetSecurity(HANDLE Handle, PEVENT_CONTEXT EventContext,
   PEVENT_INFORMATION eventInfo;
   DOKAN_FILE_INFO fileInfo;
   PDOKAN_OPEN_INFO openInfo;
-  ULONG eventInfoLength;
   NTSTATUS status = STATUS_NOT_IMPLEMENTED;
   PSECURITY_DESCRIPTOR securityDescriptor;
+  ULONG eventInfoLength = DispatchGetEventInformationLength(0);
 
-  eventInfoLength = sizeof(EVENT_INFORMATION);
   CheckFileName(EventContext->Operation.SetSecurity.FileName);
 
   eventInfo = DispatchCommon(EventContext, eventInfoLength, DokanInstance,

dokan/setfile.c

@@ -235,13 +235,14 @@ VOID DispatchSetInformation(HANDLE Handle, PEVENT_CONTEXT EventContext,
   PDOKAN_OPEN_INFO openInfo;
   DOKAN_FILE_INFO fileInfo;
   NTSTATUS status = STATUS_NOT_IMPLEMENTED;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION);
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(0);
 
   if (EventContext->Operation.SetFile.FileInformationClass == FileRenameInformation
 	  || EventContext->Operation.SetFile.FileInformationClass == FileRenameInformationEx) {
     PDOKAN_RENAME_INFORMATION renameInfo = (PDOKAN_RENAME_INFORMATION)(
         (PCHAR)EventContext + EventContext->Operation.SetFile.BufferOffset);
-    sizeOfEventInfo += renameInfo->FileNameLength;
+    sizeOfEventInfo =
+        DispatchGetEventInformationLength(renameInfo->FileNameLength);
   }
 
   CheckFileName(EventContext->Operation.SetFile.FileName);

dokan/volume.c

@@ -314,8 +314,8 @@ VOID DispatchQueryVolumeInformation(HANDLE Handle, PEVENT_CONTEXT EventContext,
   PEVENT_INFORMATION eventInfo;
   DOKAN_FILE_INFO fileInfo;
   PDOKAN_OPEN_INFO openInfo;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION) - 8 +
-                          EventContext->Operation.Volume.BufferLength;
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(
+      EventContext->Operation.Volume.BufferLength);
 
   eventInfo = (PEVENT_INFORMATION)malloc(sizeOfEventInfo);
   if (eventInfo == NULL) {

dokan/write.c

@@ -64,10 +64,10 @@ VOID DispatchWrite(HANDLE Handle, PEVENT_CONTEXT EventContext,
   NTSTATUS status;
   DOKAN_FILE_INFO fileInfo;
   BOOL bufferAllocated = FALSE;
-  ULONG sizeOfEventInfo = sizeof(EVENT_INFORMATION);
   ULONG returnedLength = 0;
   BOOL SendWriteRequestStatus = TRUE;	// otherwise DokanInstance->DokanOperations->WriteFile cannot be called
   DWORD SendWriteRequestLastError = 0;
+  ULONG sizeOfEventInfo = DispatchGetEventInformationLength(0);
 
   eventInfo = DispatchCommon(EventContext, sizeOfEventInfo, DokanInstance,
                              &fileInfo, &openInfo);