virNetworkDefUpdateIPDHCPHost: Don't crash when updating network

https://bugzilla.redhat.com/show_bug.cgi?id=1182486

When updating a network and adding new ip-dhcp-host entry, the deamon
may crash. The problem is, we iterate over existing <host/> entries
trying to compare MAC addresses to see if there's already an existing
rule. However, not all entries are required to have MAC address. For
instance, the following is perfectly valid entry:

<host id='00:04:58:fd:e4:15:1b:09:4c:0e:09:af:e4:d3:8c:b8:ca:1e'
name='redhatipv6.redhat.com' ip='2001:db8:ca2:2::119'/>

When the checking loop iterates over this, the entry's MAC address is
accessed directly. Well, the fix is obvious - check if the address is
defined before trying to compare it.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
(cherry picked from commit 7d3ae359db604f6052247ad49d7fbce1db7ef99c)

diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
index 57e7cec6b98a3d987df23c3560745fedd1f25cd6..cac12c4d47c93f36cacd5643afe7323a364beb0a 100644 (file)
--- a/src/conf/network_conf.c
+++ b/src/conf/network_conf.c
@@ -3486,7 +3486,7 @@ virNetworkDefUpdateIPDHCPHost(virNetworkDefPtr def,
         /* search for the entry with this (ip|mac|name),
          * and update the IP+(mac|name) */
         for (i = 0; i < ipdef->nhosts; i++) {
-            if ((host.mac &&
+            if ((host.mac && ipdef->hosts[i].mac &&
                  !virMacAddrCompare(host.mac, ipdef->hosts[i].mac)) ||
                 (VIR_SOCKET_ADDR_VALID(&host.ip) &&
                  virSocketAddrEqual(&host.ip, &ipdef->hosts[i].ip)) ||
@@ -3521,7 +3521,7 @@ virNetworkDefUpdateIPDHCPHost(virNetworkDefPtr def,
 
         /* log error if an entry with same name/address/ip already exists */
         for (i = 0; i < ipdef->nhosts; i++) {
-            if ((host.mac &&
+            if ((host.mac && ipdef->hosts[i].mac &&
                  !virMacAddrCompare(host.mac, ipdef->hosts[i].mac)) ||
                 (host.name &&
                  STREQ_NULLABLE(host.name, ipdef->hosts[i].name)) ||
@@ -3550,7 +3550,7 @@ virNetworkDefUpdateIPDHCPHost(virNetworkDefPtr def,
 
         /* find matching entry - all specified attributes must match */
         for (i = 0; i < ipdef->nhosts; i++) {
-            if ((!host.mac ||
+            if ((!host.mac || !ipdef->hosts[i].mac ||
                  !virMacAddrCompare(host.mac, ipdef->hosts[i].mac)) &&
                 (!host.name ||
                  STREQ_NULLABLE(host.name, ipdef->hosts[i].name)) &&