From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-sgx@vger.kernel.org
Subject: Re: [PATCH 4/5] x86/sgx: Validate TCS permssions in sgx_validate_secinfo()
Date: Thu, 22 Aug 2019 19:31:39 +0300 [thread overview]
Message-ID: <d0e8313b7817a43151b11602ad55b1136f614850.camel@linux.intel.com> (raw)
In-Reply-To: <20190822035510.GV29345@linux.intel.com>
On Wed, 2019-08-21 at 20:55 -0700, Sean Christopherson wrote:
> Why are we validating the TCS protection bits? Hardware ignores them, so
> why do we care? sgx_ioc_enclave_add_page() sets the internal protection
> bits so there's no danger of putting the wrong thing in the page tables.
I think that in this commit I got it wrong but I think this is awkward:
/*
* TCS pages must always RW set for CPU access while the SECINFO
* permissions are *always* zero - the CPU ignores the user provided
* values and silently overwrites with zero permissions.
*/
if ((secinfo.flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS)
prot |= PROT_READ | PROT_WRITE;
In my opinion the right thing to do would be check that SECINFO has *at
minimum* RW and return -EINVAL if not.
I don't like the SGX silently adjusting permissions like this.
/Jarkko
next prev parent reply other threads:[~2019-08-22 16:31 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-19 15:25 [PATCH 0/5] x86/sgx: Improve permission handing Jarkko Sakkinen
2019-08-19 15:25 ` [PATCH 1/5] x86/sgx: Document permission handling better Jarkko Sakkinen
2019-08-22 3:43 ` Sean Christopherson
2019-08-22 16:04 ` Jarkko Sakkinen
2019-08-19 15:25 ` [PATCH 2/5] x86/sgx: Use memchr_inv() in sgx_validate_secinfo() Jarkko Sakkinen
2019-08-22 3:47 ` Sean Christopherson
2019-08-22 16:20 ` Jarkko Sakkinen
2019-08-19 15:25 ` [PATCH 3/5] x86/sgx: Make sgx_validate_secinfo() more readable Jarkko Sakkinen
2019-08-22 3:48 ` Sean Christopherson
2019-08-22 16:26 ` Jarkko Sakkinen
2019-08-22 10:39 ` Ayoun, Serge
2019-08-22 16:45 ` Jarkko Sakkinen
2019-08-19 15:25 ` [PATCH 4/5] x86/sgx: Validate TCS permssions in sgx_validate_secinfo() Jarkko Sakkinen
2019-08-21 18:45 ` Jarkko Sakkinen
2019-08-22 11:33 ` Ayoun, Serge
2019-08-22 14:27 ` Sean Christopherson
2019-08-22 16:46 ` Jarkko Sakkinen
2019-08-22 16:59 ` Jarkko Sakkinen
2019-08-22 3:55 ` Sean Christopherson
2019-08-22 16:31 ` Jarkko Sakkinen [this message]
2019-08-22 16:34 ` Sean Christopherson
2019-08-23 0:39 ` Jarkko Sakkinen
2019-08-23 0:57 ` Jarkko Sakkinen
2019-08-23 2:05 ` Sean Christopherson
2019-08-23 13:41 ` Jarkko Sakkinen
2019-08-22 16:38 ` Jarkko Sakkinen
2019-08-19 15:25 ` [PATCH 5/5] x86/sgx: Rename vm_prot_bits as max_vm_flags Jarkko Sakkinen
2019-08-22 4:00 ` Sean Christopherson
2019-08-22 16:43 ` Jarkko Sakkinen
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=d0e8313b7817a43151b11602ad55b1136f614850.camel@linux.intel.com \
--to=jarkko.sakkinen@linux.intel.com \
--cc=linux-sgx@vger.kernel.org \
--cc=sean.j.christopherson@intel.com \
/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;
as well as URLs for NNTP newsgroup(s).