[tfaber] 64762: [NPFS] - Don't call RtlEqualUnicodeString (paged code) while holding a spin lock. Powered by Driver Verifier.

Author: tfaber
Date: Thu Oct 16 16:40:13 2014
New Revision: 64762

URL: http://svn.reactos.org/svn/reactos?rev=64762&view=rev
Log:
[NPFS]
- Don't call RtlEqualUnicodeString (paged code) while holding a spin lock. Powered by Driver Verifier.

Modified:
    trunk/reactos/drivers/filesystems/npfs/waitsup.c

Modified: trunk/reactos/drivers/filesystems/npfs/waitsup.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/filesystems/npfs/wa...
==============================================================================
--- trunk/reactos/drivers/filesystems/npfs/waitsup.c	[iso-8859-1] (original)
+++ trunk/reactos/drivers/filesystems/npfs/waitsup.c	[iso-8859-1] Thu Oct 16 16:40:13 2014
@@ -97,6 +97,22 @@
 {
     InitializeListHead(&WaitQueue->WaitList);
     KeInitializeSpinLock(&WaitQueue->WaitLock);
+}
+
+static
+BOOLEAN
+NpEqualUnicodeString(IN PCUNICODE_STRING String1,
+                     IN PCUNICODE_STRING String2)
+{
+    SIZE_T EqualLength;
+
+    if (String1->Length != String2->Length)
+        return FALSE;
+
+    EqualLength = RtlCompareMemory(String1->Buffer,
+                                   String2->Buffer,
+                                   String1->Length);
+    return EqualLength == String1->Length;
 }

NTSTATUS
@@ -156,7 +172,8 @@
             PipeName.MaximumLength = PipeName.Length;
         }

-        if (RtlEqualUnicodeString(&WaitName, &PipeName, FALSE))
+        /* Can't use RtlEqualUnicodeString with a spinlock held */
+        if (NpEqualUnicodeString(&WaitName, &PipeName))
         {
             /* Found a matching wait. Cancel it */
             RemoveEntryList(&WaitIrp->Tail.Overlay.ListEntry);