[NTOSKRNL_VISTA]
authorPierre Schweitzer <pierre@reactos.org>
Thu, 5 May 2016 16:58:16 +0000 (16:58 +0000)
committerPierre Schweitzer <pierre@reactos.org>
Thu, 5 May 2016 16:58:16 +0000 (16:58 +0000)
Implement FsRtlValidateReparsePointBuffer().

CORE-11172

svn path=/trunk/; revision=71264

reactos/sdk/lib/drivers/ntoskrnl_vista/fsrtl.c

index 36cc1e0..4d7831a 100644 (file)
@@ -119,3 +119,124 @@ FsRtlRemoveDotsFromPath(IN PWSTR OriginalString,
 
     return STATUS_SUCCESS;
 }
 
     return STATUS_SUCCESS;
 }
+
+FORCEINLINE
+BOOLEAN
+IsNullGuid(IN PGUID Guid)
+{
+    if (Guid->Data1 == 0 && Guid->Data2 == 0 && Guid->Data3 == 0 &&
+        ((ULONG *)Guid->Data4)[0] == 0 && ((ULONG *)Guid->Data4)[1] == 0)
+    {
+        return TRUE;
+    }
+
+    return FALSE;
+}
+
+FORCEINLINE
+BOOLEAN
+IsEven(IN USHORT Digit)
+{
+    return ((Digit & 1) != 1);
+}
+
+NTKERNELAPI
+NTSTATUS
+NTAPI
+FsRtlValidateReparsePointBuffer(IN ULONG BufferLength,
+                                IN PREPARSE_DATA_BUFFER ReparseBuffer)
+{
+    USHORT DataLength;
+    ULONG ReparseTag;
+    PREPARSE_GUID_DATA_BUFFER GuidBuffer;
+
+    /* Validate data size range */
+    if (BufferLength < REPARSE_DATA_BUFFER_HEADER_SIZE || BufferLength > MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
+    {
+        return STATUS_IO_REPARSE_DATA_INVALID;
+    }
+
+    GuidBuffer = (PREPARSE_GUID_DATA_BUFFER)ReparseBuffer;
+    DataLength = ReparseBuffer->ReparseDataLength;
+    ReparseTag = ReparseBuffer->ReparseTag;
+
+    /* Validate size consistency */
+    if (DataLength + REPARSE_DATA_BUFFER_HEADER_SIZE != BufferLength && DataLength + REPARSE_GUID_DATA_BUFFER_HEADER_SIZE != BufferLength)
+    {
+        return STATUS_IO_REPARSE_DATA_INVALID;
+    }
+
+    /* REPARSE_DATA_BUFFER is reserved for MS tags */
+    if (DataLength + REPARSE_DATA_BUFFER_HEADER_SIZE == BufferLength && !IsReparseTagMicrosoft(ReparseTag))
+    {
+        return STATUS_IO_REPARSE_DATA_INVALID;
+    }
+
+    /* If that a GUID data buffer, its GUID cannot be null, and it cannot contain a MS tag */
+    if (DataLength + REPARSE_GUID_DATA_BUFFER_HEADER_SIZE == BufferLength && ((!IsReparseTagMicrosoft(ReparseTag)
+        && IsNullGuid(&GuidBuffer->ReparseGuid)) || (ReparseTag == IO_REPARSE_TAG_MOUNT_POINT || ReparseTag == IO_REPARSE_TAG_SYMLINK)))
+    {
+        return STATUS_IO_REPARSE_DATA_INVALID;
+    }
+
+    /* Check the data for MS non reserved tags */
+    if (!(ReparseTag & 0xFFF0000) && ReparseTag != IO_REPARSE_TAG_RESERVED_ZERO && ReparseTag != IO_REPARSE_TAG_RESERVED_ONE)
+    {
+        /* If that's a mount point, validate the MountPointReparseBuffer branch */
+        if (ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
+        {
+            /* We need information */
+            if (DataLength >= REPARSE_DATA_BUFFER_HEADER_SIZE)
+            {
+                /* Substitue must be the first in row */
+                if (!ReparseBuffer->MountPointReparseBuffer.SubstituteNameOffset)
+                {
+                    /* Substitude must be null-terminated */
+                    if (ReparseBuffer->MountPointReparseBuffer.PrintNameOffset == ReparseBuffer->MountPointReparseBuffer.SubstituteNameLength + sizeof(UNICODE_NULL))
+                    {
+                        /* There must just be the Offset/Length fields + buffer + 2 null chars */
+                        if (DataLength == ReparseBuffer->MountPointReparseBuffer.PrintNameLength + ReparseBuffer->MountPointReparseBuffer.SubstituteNameLength + (FIELD_OFFSET(REPARSE_DATA_BUFFER, MountPointReparseBuffer.PathBuffer) - FIELD_OFFSET(REPARSE_DATA_BUFFER, MountPointReparseBuffer.SubstituteNameOffset)) + 2 * sizeof(UNICODE_NULL))
+                        {
+                            return STATUS_SUCCESS;
+                        }
+                    }
+                }
+            }
+        }
+        else
+        {
+#define FIELDS_SIZE (FIELD_OFFSET(REPARSE_DATA_BUFFER, SymbolicLinkReparseBuffer.PathBuffer) - FIELD_OFFSET(REPARSE_DATA_BUFFER, SymbolicLinkReparseBuffer.SubstituteNameOffset))
+
+            /* If that's not a symlink, accept the MS tag as it */
+            if (ReparseTag != IO_REPARSE_TAG_SYMLINK)
+            {
+                return STATUS_SUCCESS;
+            }
+
+            /* We need information */
+            if (DataLength >= FIELDS_SIZE)
+            {
+                /* Validate lengths */
+                if (ReparseBuffer->SymbolicLinkReparseBuffer.SubstituteNameLength && ReparseBuffer->SymbolicLinkReparseBuffer.PrintNameLength)
+                {
+                    /* Validate unicode strings */
+                    if (IsEven(ReparseBuffer->SymbolicLinkReparseBuffer.SubstituteNameLength) && IsEven(ReparseBuffer->SymbolicLinkReparseBuffer.PrintNameLength) &&
+                        IsEven(ReparseBuffer->SymbolicLinkReparseBuffer.SubstituteNameOffset) && IsEven(ReparseBuffer->SymbolicLinkReparseBuffer.PrintNameOffset))
+                    {
+                        if ((DataLength + REPARSE_DATA_BUFFER_HEADER_SIZE >= ReparseBuffer->SymbolicLinkReparseBuffer.SubstituteNameOffset + ReparseBuffer->SymbolicLinkReparseBuffer.SubstituteNameLength + FIELDS_SIZE + REPARSE_DATA_BUFFER_HEADER_SIZE)
+                            && (DataLength + REPARSE_DATA_BUFFER_HEADER_SIZE >= ReparseBuffer->SymbolicLinkReparseBuffer.PrintNameLength + ReparseBuffer->SymbolicLinkReparseBuffer.PrintNameOffset + FIELDS_SIZE + REPARSE_DATA_BUFFER_HEADER_SIZE))
+                        {
+                            return STATUS_SUCCESS;
+                        }
+                    }
+                }
+            }
+#undef FIELDS_SIZE
+        }
+
+        return STATUS_IO_REPARSE_DATA_INVALID;
+    }
+
+    return STATUS_IO_REPARSE_TAG_INVALID;
+}
+