From: Jarkko Sakkinen <jarkko@kernel.org>
To: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org, linux-sgx@vger.kernel.org,
Reinette Chatre <reinette.chatre@intel.com>,
Borislav Petkov <bp@alien8.de>,
Tianjia Zhang <tianjia.zhang@linux.alibaba.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] selftests/sgx: Fix Q1 and Q2 calculation in sigstruct.c
Date: Mon, 5 Jul 2021 08:10:39 +0300 [thread overview]
Message-ID: <20210705051039.npwagq2xd2r35v2u@kernel.org> (raw)
In-Reply-To: <20210705050922.63710-1-jarkko@kernel.org>
On Mon, Jul 05, 2021 at 08:09:21AM +0300, Jarkko Sakkinen wrote:
> From: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
>
> Q1 and Q2 are numbers with *maximum* length of 384 bytes. If the calculated
> length of Q1 and Q2 is less than 384 bytes, things will go wrong.
>
> E.g. if Q2 is 383 bytes, then
>
> 1. The bytes of q2 are copied to sigstruct->q2 in calc_q1q2().
> 2. The entire sigstruct->q2 is reversed, which results it being
> 256 * Q2, given that the last byte of sigstruct->q2 is added
> to before the bytes given by calc_q1q2().
>
> Either change in key or measurement can trigger the bug. E.g. an unmeasured
> heap could cause a devastating change in Q1 or Q2.
>
> Reverse exactly the bytes of Q1 and Q2 in calc_q1q2() before returning to
> the caller.
>
> Fixes: dedde2634570 ("selftests/sgx: Trigger the reclaimer in the selftests")
Oops :-(
Was meant to be
Fixes: 2adcba79e69d ("selftests/x86: Add a selftest for SGX")
/Jarkko
next prev parent reply other threads:[~2021-07-05 5:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-05 5:09 [PATCH v2] selftests/sgx: Fix Q1 and Q2 calculation in sigstruct.c Jarkko Sakkinen
2021-07-05 5:10 ` Jarkko Sakkinen [this message]
2021-07-23 19:53 ` Shuah Khan
2021-07-27 3:12 ` Jarkko Sakkinen
2021-07-29 21:33 ` Shuah Khan
2021-07-30 1:03 ` Jarkko Sakkinen
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