From: florian <florian@openbsd.org>
Date: Tue, 10 Oct 2023 16:09:53 +0000 (+0000)
Subject: Do not copy stack garbage, that's not going to be used.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=4f8d227ca362caaf47b25b8aa637dad1f995f487;p=openbsd

Do not copy stack garbage, that's not going to be used.

Pointed out by gcc via tb.

rdns_count is validated by all callers of propose_rdns(), so we can
trust it here to be sensible.

While here fix a pasto in an error message.

OK tb
---

diff --git a/sbin/dhcpleased/dhcpleased.c b/sbin/dhcpleased/dhcpleased.c
index 1b76a0bd38c..b5f65046894 100644
--- a/sbin/dhcpleased/dhcpleased.c
+++ b/sbin/dhcpleased/dhcpleased.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhcpleased.c,v 1.29 2023/02/15 13:47:00 florian Exp $	*/
+/*	$OpenBSD: dhcpleased.c,v 1.30 2023/10/10 16:09:53 florian Exp $	*/
 
 /*
  * Copyright (c) 2017, 2021 Florian Obser <florian@openbsd.org>
@@ -601,7 +601,7 @@ main_dispatch_engine(int fd, short event, void *bula)
 		case IMSG_WITHDRAW_RDNS: {
 			struct imsg_propose_rdns	 rdns;
 			if (IMSG_DATA_SIZE(imsg) != sizeof(rdns))
-				fatalx("%s: IMSG_PROPOSE_RDNS wrong "
+				fatalx("%s: IMSG_WITHDRAW_RDNS wrong "
 				    "length: %lu", __func__,
 				    IMSG_DATA_SIZE(imsg));
 			memcpy(&rdns, imsg.data, sizeof(rdns));
@@ -1197,7 +1197,7 @@ propose_rdns(struct imsg_propose_rdns *rdns)
 	memset(&rtdns, 0, sizeof(rtdns));
 	rtdns.sr_family = AF_INET;
 	rtdns.sr_len = 2 + rdns->rdns_count * sizeof(struct in_addr);
-	memcpy(rtdns.sr_dns, rdns->rdns, sizeof(rtdns.sr_dns));
+	memcpy(rtdns.sr_dns, rdns->rdns, rtdns.sr_len - 2);
 
 	iov[iovcnt].iov_base = &rtdns;
 	iov[iovcnt++].iov_len = sizeof(rtdns);