From 67116c69052d27dbd6d6c066104850d4d53f0041 Mon Sep 17 00:00:00 2001
From: Dmitry Chagin <dchagin@FreeBSD.org>
Date: Sat, 29 Jul 2023 11:21:35 +0300
Subject: [PATCH] linux(4): Fix control message size calculation

To determine the size in bytes needed to hold a control message
and its contents of length len, CMSG_SPACE should be used.

Reviewed by:
Differential Revision:	https://reviews.freebsd.org/D41224
MFC after:		1 week
---
 sys/compat/linux/linux_socket.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/compat/linux/linux_socket.c b/sys/compat/linux/linux_socket.c
index dd8d688a691..ac411aae1cb 100644
--- a/sys/compat/linux/linux_socket.c
+++ b/sys/compat/linux/linux_socket.c
@@ -1852,7 +1852,7 @@ cont:
 		if (error != 0)
 			goto bad;
 
-		if (outlen + LINUX_CMSG_LEN(datalen) > maxlen) {
+		if (outlen + LINUX_CMSG_SPACE(datalen) > maxlen) {
 			if (outlen == 0) {
 				error = EMSGSIZE;
 				goto err;
@@ -1871,7 +1871,7 @@ cont:
 			error = copyout(data, outbuf, datalen);
 			if (error == 0) {
 				outbuf += LINUX_CMSG_ALIGN(datalen);
-				outlen += LINUX_CMSG_LEN(datalen);
+				outlen += LINUX_CMSG_SPACE(datalen);
 			}
 		}
 err: