From: Jarkko Sakkinen <jarkko@kernel.org>
To: Dave Hansen <dave.hansen@intel.com>
Cc: linux-integrity@vger.kernel.org,
Dave Hansen <dave.hansen@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Dan Carpenter <dan.carpenter@linaro.org>,
linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] arch/x86: Fix size overflows in sgx_encl_create()
Date: Wed, 5 Mar 2025 03:26:51 +0200 [thread overview]
Message-ID: <Z8eoW4rUV5U9JUci@kernel.org> (raw)
In-Reply-To: <379e2198-55bb-4fd9-bf54-7fe0b3e33803@intel.com>
On Tue, Mar 04, 2025 at 04:30:21PM -0800, Dave Hansen wrote:
> On 3/4/25 16:19, Jarkko Sakkinen wrote:
> > On Tue, Mar 04, 2025 at 04:18:03PM -0800, Dave Hansen wrote:
> >> On 3/4/25 16:06, Jarkko Sakkinen wrote:
> >>> + /*
> >>> + * This is a micro-architectural requirement. ECREATE would detect this
> >>> + * too without mentionable overhead but this check guarantees also that
> >>> + * the space calculations for EPC and shmem allocations never overflow.
> >>> + */
> >>> + if (!is_power_of_2(secs->size))
> >>> + return -EINVAL;
> >> Isn't it a plain old documented architectural requirement?
> > Yes, but it requires some explanation why it exists here instead of
> > counting on ECREATE.
> >
> > What do you suggest?
>
> /*
> * ECREATE would detect this too, but checking here also ensures
> * that the 'encl_size' calculations below can never overflow.
> */
Looks reasonable to me!
BR, Jarkko
prev parent reply other threads:[~2025-03-05 1:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-05 0:06 [PATCH v2] arch/x86: Fix size overflows in sgx_encl_create() Jarkko Sakkinen
2025-03-05 0:09 ` Jarkko Sakkinen
2025-03-05 0:18 ` Dave Hansen
2025-03-05 0:19 ` Jarkko Sakkinen
2025-03-05 0:30 ` Dave Hansen
2025-03-05 1:26 ` Jarkko Sakkinen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Z8eoW4rUV5U9JUci@kernel.org \
--to=jarkko@kernel.org \
--cc=bp@alien8.de \
--cc=dan.carpenter@linaro.org \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sgx@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox