Normally media reports like these should be taken with a grain of salt. But there's a history of certain figures telling pals how stupid they believe Trump is. And the media usually likes McMaster.
Just look at these CNN headlines about McMaster
Trump's brilliant choice of McMaster - CNN
H.R. McMaster hinted he's not behind Trump on Iran - CNN
H.R. McMaster faces attacks from conservatives - CNNPolitics
The media doesn't generally do hit pieces about McMaster. And there's a history of McMaster or those around him leaking to the media about how their boss "manages" President Trump.
Here's a New York Times story from May.
"There is a fear among some of Mr. Trump’s senior advisers about leaving him alone in meetings with foreign leaders out of concern he might speak out of turn. General McMaster, in particular, has tried to insert caveats or gentle corrections into conversations when he believes the president is straying off topic or onto boggy diplomatic ground."
If you know anything about Washington insiders and their relationship with the media, positive reporting like this usually occurs when you build a relationship with a reporter or media outlet.
So McMaster or someone in his office wanted the New York Times to know how good of a job he was doing preventing President Trump from "speaking out of turn".
Now here's the current BuzzFeed story about what McMaster might be saying when he's all the way off the record.
National Security Advisor H.R. McMaster mocked President Trump’s intelligence at a private dinner with a powerful tech CEO, according to five sources with knowledge of the conversation.
Over a July dinner with Oracle CEO Safra Catz — who has been mentioned as a candidate for several potential administration jobs — McMaster bluntly trashed his boss, said the sources, four of whom told BuzzFeed News they heard about the exchange directly from Catz. The top national security official dismissed the president variously as an “idiot” and a “dope” with the intelligence of a “kindergartner,” the sources said.
A sixth source who was not familiar with the details of the dinner told BuzzFeed News that McMaster had made similarly derogatory comments about Trump’s intelligence to him in private, including that the president lacked the necessary brainpower to understand the matters before the National Security Council...
Three of the sources said that McMaster disparaged multiple members of the administration to Catz, including Tillerson, Secretary of Defense James Mattis, former White House Chief Strategist Steve Bannon, and President Trump’s son-in-law and senior adviser Jared Kushner.
Is this true? The principals deny everything. As they would be expected to. BuzzFeed is not a reliable outlet. But then no media outlet is these days.
There's no way to know what is and isn't true in D.C. But McMaster and Trump have their tensions. And McMaster or his people appear bent on making Trump look like he needs 'management'.
McMaster has been a terrible and unfortunate choice. He has protected and defended Obama holdovers at the NSC. And you have to wonder why anyone who truly respected Trump would do that?