git: 4682ac697ce9 - main - unix: turn check in unp_externalize() into assertion

The branch main has been updated by glebius:

URL: https://cgit.FreeBSD.org/src/commit/?id=4682ac697ce9b306d11e03a628d1ac07f4b540c8

commit 4682ac697ce9b306d11e03a628d1ac07f4b540c8
Author:     Gleb Smirnoff <glebius@FreeBSD.org>
AuthorDate: 2022-05-25 20:29:20 +0000
Commit:     Gleb Smirnoff <glebius@FreeBSD.org>
CommitDate: 2022-05-25 20:29:20 +0000

    unix: turn check in unp_externalize() into assertion
    
    In this function we always work with mbufs that we previously
    created ourselves in unp_internalize().  They must be valid.
    
    Reviewed by:            markj
    Differential revision:  https://reviews.freebsd.org/D35319
---
 sys/kern/uipc_usrreq.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index cf9e04034760..c9e40c664042 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -2015,10 +2015,8 @@ unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
 	if (controlp != NULL) /* controlp == NULL => free control messages */
 		*controlp = NULL;
 	while (cm != NULL) {
-		if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
-			error = EINVAL;
-			break;
-		}
+		MPASS(clen >= sizeof(*cm) && clen <= cm->cmsg_len);
+
 		data = CMSG_DATA(cm);
 		datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
 		if (cm->cmsg_level == SOL_SOCKET