diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c
index 83322cd7673a..77c63c3f820f 100644
--- a/drivers/virt/coco/tdx-guest/tdx-guest.c
+++ b/drivers/virt/coco/tdx-guest/tdx-guest.c
@@ -170,8 +170,6 @@ static void tdx_mr_deinit(const struct attribute_group *mr_grp)
 #define GET_QUOTE_SUCCESS		0
 #define GET_QUOTE_IN_FLIGHT		0xffffffffffffffff
 
-#define TDX_QUOTE_MAX_LEN		(GET_QUOTE_BUF_SIZE - sizeof(struct tdx_quote_buf))
-
 /* struct tdx_quote_buf: Format of Quote request buffer.
  * @version: Quote format version, filled by TD.
  * @status: Status code of Quote request, filled by VMM.
@@ -313,7 +311,7 @@ static int tdx_report_new_locked(struct tsm_report *report)
 
 	out_len = READ_ONCE(quote_buf->out_len);
 
-	if (out_len > TDX_QUOTE_MAX_LEN)
+	if (struct_size(quote_buf, data, out_len) > GET_QUOTE_BUF_SIZE)
 		return -EFBIG;
 
 	buf = kvmemdup(quote_buf->data, out_len, GFP_KERNEL);