Fix memory leak in __FreePage()

The pool memory for the MDL also needs to be freed.

Also, generalise __AllocatePage() and __FreePage() to __AllocatePages()
and __FreePages() to allow for multi-page allocations in future.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>

diff --git a/src/xeniface/util.h b/src/xeniface/util.h
index 13a673497f530710ad3b67627afcf1f730e42121..b63db2c8ba69bd502ab9dd6806b2acdb26cf1ab8 100644 (file)
--- a/src/xeniface/util.h
+++ b/src/xeniface/util.h
@@ -168,8 +168,8 @@ __FreePoolWithTag(
 }
 
 static FORCEINLINE PMDL
-__AllocatePage(
-    VOID
+__AllocatePages(
+    IN  ULONG           Count
     )
 {
     PHYSICAL_ADDRESS    LowAddress;
@@ -183,7 +183,7 @@ __AllocatePage(
     LowAddress.QuadPart = 0ull;
     HighAddress.QuadPart = ~0ull;
     SkipBytes.QuadPart = 0ull;
-    TotalBytes = (SIZE_T)PAGE_SIZE;
+    TotalBytes = (SIZE_T)PAGE_SIZE * Count;
 
     Mdl = MmAllocatePagesForMdlEx(LowAddress,
                                   HighAddress,
@@ -196,6 +196,9 @@ __AllocatePage(
     if (Mdl == NULL)
         goto fail1;
 
+    if (Mdl->ByteCount < TotalBytes)
+        goto fail2;
+
     ASSERT((Mdl->MdlFlags & (MDL_MAPPED_TO_SYSTEM_VA |
                              MDL_PARTIAL_HAS_BEEN_MAPPED |
                              MDL_PARTIAL |
@@ -212,14 +215,17 @@ __AllocatePage(
 
     status = STATUS_UNSUCCESSFUL;
     if (MdlMappedSystemVa == NULL)
-        goto fail2;
+        goto fail3;
 
     ASSERT3P(MdlMappedSystemVa, ==, Mdl->MappedSystemVa);
 
-    RtlZeroMemory(MdlMappedSystemVa, PAGE_SIZE);
+    RtlZeroMemory(MdlMappedSystemVa, Mdl->ByteCount);
 
     return Mdl;
 
+fail3:
+    Error("fail3\n");
+
 fail2:
     Error("fail2\n");
 
@@ -232,8 +238,10 @@ fail1:
     return NULL;
 }
 
+#define __AllocatePage()    __AllocatePages(1)
+
 static FORCEINLINE VOID
-__FreePage(
+__FreePages(
     IN PMDL    Mdl
     )
 {
@@ -242,13 +250,14 @@ __FreePage(
     ASSERT(Mdl->MdlFlags & MDL_MAPPED_TO_SYSTEM_VA);
     MdlMappedSystemVa = Mdl->MappedSystemVa;
 
-    RtlFillMemory(MdlMappedSystemVa, PAGE_SIZE, 0xAA);
-
     MmUnmapLockedPages(MdlMappedSystemVa, Mdl);
 
     MmFreePagesFromMdl(Mdl);
+    ExFreePool(Mdl);
 }
 
+#define __FreePage(_Mdl)    __FreePages(_Mdl)
+
 static FORCEINLINE PCHAR
 __strtok_r(
     IN      PCHAR   Buffer,