[rpcbind PATCH 5/6] rpcbind: check for null netmask in addrmerge()

[Scott Mayhew <smayhew@redhat.com>]

getifaddrs(3) states that ifa_netmask may contain a null pointer, so we
should skip interfaces where ifa_netmask is null to avoid triggering a
null dereference in bitmaskcmp().

This is mainly a defensive change - we only call bitmaskcmp() for
AF_INET/AF_INET6 addresses, and I'm not sure it's possible for an
interface to have an IP address but no netmask.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
 src/util.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/util.c b/src/util.c
index ead4899..a61a8c6 100644
--- a/src/util.c
+++ b/src/util.c
@@ -165,7 +165,8 @@ addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
 		ifsa = ifap->ifa_addr;
 		ifmasksa = ifap->ifa_netmask;
 
-		if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family ||
+		if (ifsa == NULL || ifmasksa == NULL ||
+		    ifsa->sa_family != hint_sa->sa_family ||
 		    !(ifap->ifa_flags & IFF_UP))
 			continue;
 
-- 
2.55.0