Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20260331040317.GA31713@openwall.com>
Date: Tue, 31 Mar 2026 06:03:17 +0200
From: Solar Designer <solar@...nwall.com>
To: Sandipan Roy <saroy@...hat.com>
Cc: oss-security@...ts.openwall.com, Paolo Bonzini <pbonzini@...hat.com>,
	denis.pilipchuk@...cle.com, bkov@...zon.com, fgriffo@...zon.com,
	Yogesh Mittal <ymittal@...hat.com>,
	Mauro Matteo Cascella <mcascell@...hat.com>
Subject: Re: KVM shadow EPT stale rmap use-after-free

Hi,

On Mon, Mar 30, 2026 at 11:34:02AM +0530, Sandipan Roy wrote:
> Alexander Bulekov(bkov@...zon.com) and Fred Griffoul (fgriffo@...zon.com)
> reported a use-after-free in KVM's shadow paging code.

Thank you all for finding and handling this issue, including bringing it
to oss-security.

Sandipan Roy first brought this to linux-distros on March 10, writing:

On Tue, Mar 10, 2026 at 04:03:41PM +0530, Sandipan Roy wrote:
> The reporters and maintainers have agreed on an embargo until Sunday
> March 29, 2026, 16:00 UTC. The Linux kernel security team did not object
> to extending the embargo period past the documented limit of 14 calendar
> days

to which I replied:

On Thu, Mar 12, 2026 at 06:04:33PM +0100, Solar Designer wrote:
> We have a problem here: we also have a 14 days maximum on linux-distros,
> and no one asked us whether we'd be willing to make an exception.  As
> linux-distros list admin, if asked in advance, I would object to this.
> More precisely, I'd have asked to delay notification to linux-distros
> until no more than 14 days remain until embargo end.
>
> But what's done, is done.

So here I am acknowledging the policy violation and explaining how it
happened and why I let it happen.  With a precise planned public
disclosure date/time only moderately in excess of the usual maximum, and
with many other stakeholders involved, I felt it would be
counter-productive to insist on public disclosure after at most 14 days
per the policy.

Looking at distros list statistics, we previously let the 14 days be
exceeded to a similar extent a year ago, in March 2025.  Here's my
explanation of that previous occasion (also related to Linux kernel):

https://www.openwall.com/lists/oss-security/2025/04/01/6

Here are the statistics (until end of February - I'll add March likely
in mid-April like I usually do):

https://oss-security.openwall.org/wiki/mailing-lists/distros/stats

The maximum we had since mid-2023 when Linux Foundation sponsorship
started is a little over 20 days, so just like we had this time.  This
maximum was reached 3 times in these almost 4 years.  The rest of cases
are at most 15.5 days (on one occasion; the rest are below 15).  Prior
to mid-2023, things were occasionally a lot worse as I wasn't keeping
track of list statistics like I do now.

Alexander

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.