tipc: fix an infoleak in tipc_nl_compat_link_dump

link_info.str is a char array of size 60. Memory after the NULL
byte is not initialized. Sending the whole object out can cause
a leak.
Signed-off-by: NKangjie Lu <kjlu@gatech.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/tipc/netlink_compat.c

@@ -604,7 +604,8 @@ static int tipc_nl_compat_link_dump(struct tipc_nl_compat_msg *msg,
 
 	link_info.dest = nla_get_flag(link[TIPC_NLA_LINK_DEST]);
 	link_info.up = htonl(nla_get_flag(link[TIPC_NLA_LINK_UP]));
-	strcpy(link_info.str, nla_data(link[TIPC_NLA_LINK_NAME]));
+	nla_strlcpy(link_info.str, nla_data(link[TIPC_NLA_LINK_NAME]),
+		    TIPC_MAX_LINK_NAME);
 
 	return tipc_add_tlv(msg->rep, TIPC_TLV_LINK_INFO,
 			    &link_info, sizeof(link_info));