Don't desallocate non allocated memory

svn path=/trunk/; revision=15004

diff --git a/reactos/drivers/dd/serial/circularbuffer.c b/reactos/drivers/dd/serial/circularbuffer.c
index 521f0ab..1c7d709 100644 (file)
--- a/reactos/drivers/dd/serial/circularbuffer.c
+++ b/reactos/drivers/dd/serial/circularbuffer.c
@@ -32,7 +32,8 @@ FreeCircularBuffer(
 {
        DPRINT("Serial: FreeCircularBuffer(pBuffer %p)\n", pBuffer);
        ASSERT(pBuffer);
-       ExFreePoolWithTag(pBuffer->Buffer, SERIAL_TAG);
+       if (pBuffer->Buffer != NULL)
+               ExFreePoolWithTag(pBuffer->Buffer, SERIAL_TAG);
        return STATUS_SUCCESS;
 }