From: Thomas Gleixner <tglx@linutronix.de>
To: "Maciej W. Rozycki" <macro@orcam.me.uk>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>,
Kees Cook <keescook@chromium.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PING][PATCH v3] x86: Use `get_random_u8' for kernel stack offset randomization
Date: Mon, 13 Feb 2023 20:01:31 +0100 [thread overview]
Message-ID: <877cwltmno.ffs@tglx> (raw)
In-Reply-To: <alpine.DEB.2.21.2302122311470.46819@angie.orcam.me.uk>
On Sun, Feb 12 2023 at 23:17, Maciej W. Rozycki wrote:
> On Mon, 30 Jan 2023, Maciej W. Rozycki wrote:
>
>> For x86 kernel stack offset randomization uses the RDTSC instruction,
>> which according to H. Peter Anvin is not a secure source of entropy:
>>
>> "RDTSC isn't a super fast instruction either, but what is *way* more
>> significant is that this use of RDTSC is NOT safe: in certain power states
>> it may very well be that stone number of lower bits of TSC contain no
>> entropy at all."
>
> Ping for:
> <https://lore.kernel.org/all/alpine.DEB.2.21.2301302011150.55843@angie.orcam.me.uk/>.
I'm waiting for you to address Peter Anvins feedback. You also cite him
w/o providing a link to the conversation, so any context is missing.
Thanks,
tglx
next prev parent reply other threads:[~2023-02-13 19:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-30 21:30 [PATCH v3] x86: Use `get_random_u8' for kernel stack offset randomization Maciej W. Rozycki
2023-01-31 19:34 ` Jason A. Donenfeld
2023-01-31 20:52 ` H. Peter Anvin
2023-01-31 21:01 ` Miko Larsson
2023-02-12 23:17 ` [PING][PATCH " Maciej W. Rozycki
2023-02-13 19:01 ` Thomas Gleixner [this message]
2023-02-14 4:54 ` Maciej W. Rozycki
2023-02-14 20:43 ` H. Peter Anvin
2023-02-22 16:44 ` Jason A. Donenfeld
2023-02-13 19:03 ` [PATCH " Thomas Gleixner
2023-02-14 5:12 ` Maciej W. Rozycki
2023-02-14 13:39 ` Jason A. Donenfeld
2023-02-22 12:05 ` Maciej W. Rozycki
2023-06-05 15:45 ` Maciej W. Rozycki
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