[PATCH] Add overflow check to socket_wrapper

[Volker Lendecke]

Hi!

Review appreciated!

Thanks, Volker

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From f0d0f5c3ce38702252e1b07b3a1f7082f2e6c7b5 Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl at samba.org>
Date: Sat, 29 Dec 2018 20:20:13 +0100
Subject: [PATCH] swrap: Add an overflow check

Signed-off-by: Volker Lendecke <vl at samba.org>
---
 src/socket_wrapper.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/socket_wrapper.c b/src/socket_wrapper.c
index df70df5008d..a0e1df044a6 100644
--- a/src/socket_wrapper.c
+++ b/src/socket_wrapper.c
@@ -4752,6 +4752,11 @@ static ssize_t swrap_sendmsg_before(int fd,
 		for (i = 0; i < (size_t)msg->msg_iovlen; i++) {
 			size_t nlen;
 			nlen = len + msg->msg_iov[i].iov_len;
+			if (nlen < len) {
+				/* overflow */
+				errno = EMSGSIZE;
+				goto out;
+			}
 			if (nlen > mtu) {
 				break;
 			}
-- 
2.11.0