[reactos] 01/01: [NTOS:EX] ExUuidCreate(): Correctly fill Uuid->Data4

[Serge Gautherie]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=7790670dd80c5d4cf3c4b6...

commit 7790670dd80c5d4cf3c4b68f8327fe97126c6229
Author:     Serge Gautherie [e-mail]
AuthorDate: Wed Sep 9 03:46:56 2020 +0200
Commit:     Timo Kreuzer [e-mail]
CommitDate: Sat Oct 17 15:00:19 2020 +0200

[NTOS:EX] ExUuidCreate(): Correctly fill Uuid->Data4

ROSTESTS-359

Co-authored-by: Nguyen Trung Khanh [e-mail]
---
 ntoskrnl/ex/uuid.c             | 10 ++++++----
 ntoskrnl/include/internal/ex.h | 13 ++++++++++---
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/ntoskrnl/ex/uuid.c b/ntoskrnl/ex/uuid.c
index 0d198fbe4fe..b69200b1a86 100644
--- a/ntoskrnl/ex/uuid.c
+++ b/ntoskrnl/ex/uuid.c
@@ -42,7 +42,7 @@ LARGE_INTEGER ExpUuidLastTimeAllocated;
 ULONG ExpUuidSequenceNumber = 0;
 BOOLEAN ExpUuidSequenceNumberValid;
 BOOLEAN ExpUuidSequenceNumberNotSaved = FALSE;
-UUID_CACHED_VALUES_STRUCT ExpUuidCachedValues = {0ULL, 0xFFFFFFFF, 0, 0, { 0x80, 0x6E, 0x6F, 0x6E, 0x69, 0x63}};
+UUID_CACHED_VALUES_STRUCT ExpUuidCachedValues = {0ULL, 0xFFFFFFFF, {{0, 0, {0x80, 0x6E, 0x6F, 0x6E, 0x69, 0x63}}}};
 BOOLEAN ExpUuidCacheValid = FALSE;
 ULONG ExpLuidIncrement = 1;
 LARGE_INTEGER ExpLuid = {{0x3e9, 0x0}};
@@ -400,9 +400,11 @@ ExUuidCreate(OUT UUID *Uuid)
         {
             Time.QuadPart = ExpUuidCachedValues.Time;

-            RtlCopyMemory(&Uuid->Data4[0],
-                          &ExpUuidCachedValues.NodeId[0],
-                          SEED_BUFFER_SIZE);
+            C_ASSERT(sizeof(ExpUuidCachedValues.GuidInit) == sizeof(Uuid->Data4));
+            RtlCopyMemory(Uuid->Data4,
+                          ExpUuidCachedValues.GuidInit,
+                          sizeof(Uuid->Data4));
+
             Valid = ExpUuidCacheValid;
             AllocatedCount = InterlockedDecrement(&ExpUuidCachedValues.AllocatedCount);
         }
diff --git a/ntoskrnl/include/internal/ex.h b/ntoskrnl/include/internal/ex.h
index 52e58bffbef..0690b7b9801 100644
--- a/ntoskrnl/include/internal/ex.h
+++ b/ntoskrnl/include/internal/ex.h
@@ -171,9 +171,16 @@ typedef struct _UUID_CACHED_VALUES_STRUCT
 {
     ULONGLONG Time;
     LONG AllocatedCount;
-    UCHAR ClockSeqHiAndReserved;
-    UCHAR ClockSeqLow;
-    UCHAR NodeId [ 6 ] ;
+    union
+    {
+        struct
+        {
+            UCHAR ClockSeqHiAndReserved;
+            UCHAR ClockSeqLow;
+            UCHAR NodeId[6 /*SEED_BUFFER_SIZE*/];
+        };
+        UCHAR GuidInit[8]; /* Match GUID.Data4 */
+    };
 } UUID_CACHED_VALUES_STRUCT, *PUUID_CACHED_VALUES_STRUCT;

/* INITIALIZATION FUNCTIONS *************************************************/