diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c
index 08d95e1ecc5e..f7c907143834 100644
--- a/fs/ksmbd/smb_common.c
+++ b/fs/ksmbd/smb_common.c
@@ -266,7 +266,7 @@ static int ksmbd_negotiate_smb_dialect(void *buf)
 		if (smb2_neg_size > smb_buf_length)
 			goto err_out;
 
-		if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) >
+		if (struct_size(req, Dialects, le16_to_cpu(req->DialectCount)) >
 		    smb_buf_length)
 			goto err_out;