From: Otto Moerbeek <otto.moerbeek@open-xchange.com>
Date: Fri, 28 Jun 2019 09:25:32 +0000 (+0200)
Subject: Clear CMSG_SPACE(sizeof(data)) in cmsghdr to appease valgrind.
X-Git-Tag: dnsdist-1.4.0-rc1~84^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F7996%2Fhead;p=thirdparty%2Fpdns.git

Clear CMSG_SPACE(sizeof(data)) in cmsghdr to appease valgrind.
---

diff --git a/pdns/misc.cc b/pdns/misc.cc
index 2686b0fc46..db7e780bff 100644
--- a/pdns/misc.cc
+++ b/pdns/misc.cc
@@ -901,7 +901,8 @@ void addCMsgSrcAddr(struct msghdr* msgh, cmsgbuf_aligned* cmsgbuf, const ComboAd
     cmsg->cmsg_len = CMSG_LEN(sizeof(*pkt));
 
     pkt = (struct in6_pktinfo *) CMSG_DATA(cmsg);
-    memset(pkt, 0, sizeof(*pkt));
+    // Include the padding to stop valgrind complaining about passing uninitialized data
+    memset(pkt, 0, CMSG_SPACE(sizeof(*pkt)));
     pkt->ipi6_addr = source->sin6.sin6_addr;
     pkt->ipi6_ifindex = itfIndex;
   }
@@ -918,7 +919,8 @@ void addCMsgSrcAddr(struct msghdr* msgh, cmsgbuf_aligned* cmsgbuf, const ComboAd
     cmsg->cmsg_len = CMSG_LEN(sizeof(*pkt));
 
     pkt = (struct in_pktinfo *) CMSG_DATA(cmsg);
-    memset(pkt, 0, sizeof(*pkt));
+    // Include the padding to stop valgrind complaining about passing uninitialized data
+    memset(pkt, 0, CMSG_SPACE(sizeof(*pkt)));
     pkt->ipi_spec_dst = source->sin4.sin_addr;
     pkt->ipi_ifindex = itfIndex;
 #elif defined(IP_SENDSRCADDR)
@@ -932,7 +934,9 @@ void addCMsgSrcAddr(struct msghdr* msgh, cmsgbuf_aligned* cmsgbuf, const ComboAd
     cmsg->cmsg_type = IP_SENDSRCADDR;
     cmsg->cmsg_len = CMSG_LEN(sizeof(*in));
 
+    // Include the padding to stop valgrind complaining about passing uninitialized data
     in = (struct in_addr *) CMSG_DATA(cmsg);
+    memset(in, 0, CMSG_SPACE(sizeof(*in)));
     *in = source->sin4.sin_addr;
 #endif
   }