From: Jann Horn <jannh@google.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: "Catangiu, Adrian Costin" <acatan@amazon.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"linux-api@vger.kernel.org" <linux-api@vger.kernel.org>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"rjw@rjwysocki.net" <rjw@rjwysocki.net>,
"len.brown@intel.com" <len.brown@intel.com>,
"mhocko@kernel.org" <mhocko@kernel.org>,
"fweimer@redhat.com" <fweimer@redhat.com>,
"keescook@chromium.org" <keescook@chromium.org>,
"luto@amacapital.net" <luto@amacapital.net>,
"wad@chromium.org" <wad@chromium.org>,
"mingo@kernel.org" <mingo@kernel.org>,
"bonzini@gnu.org" <bonzini@gnu.org>, "Graf (AWS),
Alexander" <graf@amazon.de>,
"MacCarthaigh, Colm" <colmmacc@amazon.com>,
"Singh, Balbir" <sblbir@amazon.com>,
"Sandu, Andrei" <sandreim@amazon.com>,
"Brooker, Marc" <mbrooker@amazon.com>,
"Weiss, Radu" <raduweis@amazon.com>,
"Manwaring, Derek" <derekmn@amazon.com>
Subject: Re: [RFC]: mm,power: introduce MADV_WIPEONSUSPEND
Date: Sat, 4 Jul 2020 00:56:03 +0200 [thread overview]
Message-ID: <CAG48ez0oWQd42a-H-Dzw1Wq7HgB5PpFRGCZeYxP8ohxaoZHmvQ@mail.gmail.com> (raw)
In-Reply-To: <20200703224411.GC25072@amd>
On Sat, Jul 4, 2020 at 12:44 AM Pavel Machek <pavel@ucw.cz> wrote:
> > Cryptographic libraries carry pseudo random number generators to
> > quickly provide randomness when needed. If such a random pool gets
> > cloned, secrets may get revealed, as the same random number may get
> > used multiple times. For fork, this was fixed using the WIPEONFORK
> > madvise flag [1].
>
> > Unfortunately, the same problem surfaces when a virtual machine gets
> > cloned. The existing flag does not help there. This patch introduces a
> > new flag to automatically clear memory contents on VM suspend/resume,
> > which will allow random number generators to reseed when virtual
> > machines get cloned.
>
> Umm. If this is real problem, should kernel provide such rng in the
> vsdo page using vsyscalls? Kernel can have special interface to its
> vsyscalls, but we may not want to offer this functionality to rest of
> userland...
And then the kernel would just need to maintain a sequence
number in the vDSO data page that gets bumped on suspend, right?
next prev parent reply other threads:[~2020-07-03 22:56 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-03 10:34 Catangiu, Adrian Costin
2020-07-03 11:04 ` Jann Horn
2020-07-04 1:33 ` Colm MacCárthaigh
2020-07-06 12:09 ` Alexander Graf
2020-07-03 11:30 ` Michal Hocko
2020-07-03 12:17 ` Rafael J. Wysocki
2020-07-03 22:39 ` Pavel Machek
2020-07-03 13:29 ` Jann Horn
2020-07-03 22:34 ` Pavel Machek
2020-07-03 22:53 ` Jann Horn
2020-07-07 7:38 ` Michal Hocko
2020-07-07 8:07 ` Pavel Machek
2020-07-07 8:58 ` Michal Hocko
2020-07-07 16:37 ` Pavel Machek
2020-07-07 19:00 ` Colm MacCarthaigh
2020-07-12 7:22 ` Pavel Machek
2020-07-13 8:02 ` Michal Hocko
2020-07-04 1:45 ` Colm MacCárthaigh
2020-07-07 7:40 ` Michal Hocko
2020-07-03 22:44 ` Pavel Machek
2020-07-03 22:56 ` Jann Horn [this message]
2020-07-04 11:48 ` Pavel Machek
2020-07-06 12:26 ` Alexander Graf
2020-07-06 12:52 ` Jann Horn
2020-07-06 13:14 ` Alexander Graf
2020-07-07 7:44 ` Michal Hocko
2020-07-07 8:01 ` Alexander Graf
2020-07-07 9:14 ` Michal Hocko
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