From ce42ce038efdc1508aaf2364eedb227a5a0781c3 Mon Sep 17 00:00:00 2001 From: "Bjoern A. Zeeb" Date: Wed, 3 Feb 2016 11:03:44 +0000 Subject: [PATCH] Try to fix a bug introduced in r228623. We started to copy the ifa_msghdr as otherwise platforms with strict alignment would break. It's unclear to me if there's also a problem with access to the address list following the structure. However we never copied the address list after the structure and thus are pointing at random memory. For now just use a pointer to the original memory for accessing the address list making it at least work on platforms with weak memory access. PR: 195445 Reported by: wolfgang lyxys.ka.sub.org Tested by: wolfgang lyxys.ka.sub.org (x86) MFC after: 3 days --- contrib/bsnmp/snmp_mibII/mibII.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/contrib/bsnmp/snmp_mibII/mibII.c b/contrib/bsnmp/snmp_mibII/mibII.c index b62ee66d6d61..9079d1d3b58c 100644 --- a/contrib/bsnmp/snmp_mibII/mibII.c +++ b/contrib/bsnmp/snmp_mibII/mibII.c @@ -982,7 +982,7 @@ handle_rtmsg(struct rt_msghdr *rtm) { struct sockaddr *addrs[RTAX_MAX]; struct if_msghdr *ifm; - struct ifa_msghdr ifam; + struct ifa_msghdr ifam, *ifamp; struct ifma_msghdr *ifmam; #ifdef RTM_IFANNOUNCE struct if_announcemsghdr *ifan; @@ -1002,8 +1002,9 @@ handle_rtmsg(struct rt_msghdr *rtm) switch (rtm->rtm_type) { case RTM_NEWADDR: - memcpy(&ifam, rtm, sizeof(ifam)); - mib_extract_addrs(ifam.ifam_addrs, (u_char *)(&ifam + 1), addrs); + ifamp = (struct ifa_msghdr *)rtm; + memcpy(&ifam, ifamp, sizeof(ifam)); + mib_extract_addrs(ifam.ifam_addrs, (u_char *)(ifamp + 1), addrs); if (addrs[RTAX_IFA] == NULL || addrs[RTAX_NETMASK] == NULL) break; @@ -1029,8 +1030,9 @@ handle_rtmsg(struct rt_msghdr *rtm) break; case RTM_DELADDR: - memcpy(&ifam, rtm, sizeof(ifam)); - mib_extract_addrs(ifam.ifam_addrs, (u_char *)(&ifam + 1), addrs); + ifamp = (struct ifa_msghdr *)rtm; + memcpy(&ifam, ifamp, sizeof(ifam)); + mib_extract_addrs(ifam.ifam_addrs, (u_char *)(ifamp + 1), addrs); if (addrs[RTAX_IFA] == NULL) break;