From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
linux-sgx@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Jethro Beekman <jethro@fortanix.com>,
Darren Kenny <darren.kenny@oracle.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
asapek@google.com, Borislav Petkov <bp@alien8.de>,
"Xing, Cedric" <cedric.xing@intel.com>,
chenalexchen@google.com, Conrad Parker <conradparker@google.com>,
cyhanish@google.com, Dave Hansen <dave.hansen@intel.com>,
"Huang, Haitao" <haitao.huang@intel.com>,
Josh Triplett <josh@joshtriplett.org>,
"Huang, Kai" <kai.huang@intel.com>,
"Svahn, Kai" <kai.svahn@intel.com>, Keith Moyer <kmoy@google.com>,
Christian Ludloff <ludloff@google.com>,
Neil Horman <nhorman@redhat.com>,
Nathaniel McCallum <npmccallum@redhat.com>,
Patrick Uiterwijk <puiterwijk@redhat.com>,
David Rientjes <rientjes@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
yaozhangx@google.com
Subject: Re: [PATCH v38 10/24] mm: Add vm_ops->mprotect()
Date: Mon, 21 Sep 2020 14:18:49 -0700 [thread overview]
Message-ID: <20200921211849.GA25403@linux.intel.com> (raw)
In-Reply-To: <20200921210736.GB58176@linux.intel.com>
On Tue, Sep 22, 2020 at 12:07:36AM +0300, Jarkko Sakkinen wrote:
> On Mon, Sep 21, 2020 at 09:57:58AM -0700, Sean Christopherson wrote:
> > On Mon, Sep 21, 2020 at 03:49:46PM +0300, Jarkko Sakkinen wrote:
> > > On Fri, Sep 18, 2020 at 04:53:37PM -0700, Sean Christopherson wrote:
> > > > a noexec filesystem by loading code into an enclave, and to give the kernel the
> > > > option of adding enclave specific LSM policies in the future.
> > > >
> > > > The source file (if one exists) for the enclave is long gone when the enclave
> > > > is actually mmap()'d and mprotect()'d. To enforce noexec, the requested
> > > > permissions for a given page are snapshotted when the page is added to the
> > > > enclave, i.e. when the enclave is built. Enclave pages that will be executable
> > > > must originate from an a MAYEXEC VMA, e.g. the source page can't come from a
> > > > noexec file system.
> > >
> > > noexec check is done in __sgx_encl_add_page(), not in this callback.
> > > sgx_vma_mprotect() calls sgx_encl_may_map(), which iterates the
> > > addresses, checks that permissions are not surpassed and there are
> > > no holes.
> >
> > Yes, that's what I said.
>
> sgx_encl_add_page() will remove such page. The callback does not
> interact with this process as such pages never get to the enclave.
I think we're in violent agreement, mostly.
Userspace can add the page without EXEC permissions in the EPCM, and thus
avoid the noexec/VM_MAYEXEC check. The enclave can then do EMODPE to gain
EXEC permissions in the EPMC. Without the ->mprotect() hook, we wouldn't
be able to detect/prevent such shenanigans.
> > I would copy-paste the part of the response that was snipped...
>
> I do agree with the main conclusions but it contains also things that I
> do not see relating that much, like noexec partitions.
As above, this does directly related to noexec/VM_MAYEXEC.
> It goes too far in detail what will LSM's end up doing. I absolutely do not
> want to forecast too far how LSM hooks would work.
That's fine, I was responding to Andy's question, not intending to write a
changelog.
> Since we do not have ioctl's for EMODPE and such, I see EMODPE as the
> only reason for doing this right now. Otherwise, we are in trouble with
> any possible LSM callbacks. For any sort of access control decision,
> things decided must stick.
Yes, again, violent agreement :-).
> I would add something like this to the commit message largely based on
> your text:
>
> "SGX stores the permissions for each page when they are first added, and
> will implement this callback to check that mmap() or mprotect() does not
> surpass these permissions in the requested address range.
>
> This is done to prevent using EMODPE upgrading permissions of a page
> after mmap() or mprotect() has been done, which would prevent any sort
> of LSM callbacks to be implemented later on because the access control
> decision could deprecate."
next prev parent reply other threads:[~2020-09-21 21:18 UTC|newest]
Thread overview: 182+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-15 11:28 [PATCH v38 00/24] Intel SGX foundations Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 01/24] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 02/24] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 03/24] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-09-16 11:44 ` Borislav Petkov
2020-09-16 20:30 ` Jarkko Sakkinen
2020-09-16 20:32 ` Borislav Petkov
2020-09-15 11:28 ` [PATCH v38 04/24] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 05/24] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 06/24] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 07/24] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 08/24] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 09/24] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 10/24] mm: Add vm_ops->mprotect() Jarkko Sakkinen
2020-09-18 12:44 ` Borislav Petkov
2020-09-18 15:09 ` Andy Lutomirski
2020-09-18 23:24 ` [PATCH v38 10/24] mm: Add vm_ops->mprotect()' Jarkko Sakkinen
2020-09-18 23:53 ` [PATCH v38 10/24] mm: Add vm_ops->mprotect() Sean Christopherson
2020-09-19 0:15 ` Andy Lutomirski
[not found] ` <20200922125801.GA133710@linux.intel.com>
2020-09-22 15:11 ` Dave Hansen
2020-09-23 13:30 ` Jarkko Sakkinen
2020-09-23 13:43 ` Jarkko Sakkinen
2020-09-23 14:33 ` Jarkko Sakkinen
2020-09-24 14:50 ` Dave Hansen
2020-09-24 16:27 ` Sean Christopherson
[not found] ` <20200921124946.GF6038@linux.intel.com>
2020-09-21 12:51 ` Jarkko Sakkinen
2020-09-21 13:14 ` Jarkko Sakkinen
[not found] ` <20200921165758.GA24156@linux.intel.com>
2020-09-21 21:07 ` Jarkko Sakkinen
2020-09-21 21:18 ` Sean Christopherson [this message]
2020-09-22 5:29 ` Jarkko Sakkinen
2020-09-22 5:35 ` Jarkko Sakkinen
2020-09-22 16:43 ` Sean Christopherson
2020-09-23 13:50 ` Jarkko Sakkinen
2020-09-24 19:11 ` Haitao Huang
2020-09-24 19:28 ` Sean Christopherson
2020-09-24 19:39 ` Dave Hansen
2020-09-24 20:01 ` Sean Christopherson
2020-09-24 20:10 ` Dave Hansen
2020-09-24 20:25 ` Sean Christopherson
2020-09-24 20:54 ` Dave Hansen
2020-09-24 23:05 ` Sean Christopherson
2020-09-24 23:09 ` Dave Hansen
2020-09-25 0:00 ` Sean Christopherson
2020-09-25 17:18 ` Dave Hansen
2020-09-25 19:43 ` Sean Christopherson
2020-09-25 19:53 ` Dave Hansen
2020-09-26 4:15 ` Andy Lutomirski
2020-09-28 0:53 ` Jarkko Sakkinen
2020-09-28 14:04 ` Dave Hansen
2020-09-28 16:19 ` Jarkko Sakkinen
2020-09-28 16:48 ` Dave Hansen
2020-09-28 19:32 ` Jarkko Sakkinen
2020-09-28 19:45 ` Dave Hansen
2020-09-28 20:19 ` Jarkko Sakkinen
2020-09-29 1:37 ` Andy Lutomirski
2020-09-29 4:05 ` Jarkko Sakkinen
2020-09-29 14:24 ` Dave Hansen
2020-09-30 0:20 ` Jarkko Sakkinen
2020-09-30 14:35 ` Dave Hansen
2020-09-28 20:18 ` Jarkko Sakkinen
2020-10-18 8:49 ` Dr. Greg
2020-10-19 21:31 ` Sean Christopherson
2020-10-20 10:01 ` Dr. Greg
2020-10-20 16:40 ` Sean Christopherson
2020-10-24 14:37 ` Dr. Greg
2020-10-24 15:33 ` Andy Lutomirski
2020-10-26 10:51 ` Dr. Greg
2020-10-26 22:59 ` Andy Lutomirski
2020-10-27 0:40 ` Sean Christopherson
2020-09-24 22:07 ` Jarkko Sakkinen
2020-09-24 21:58 ` Jarkko Sakkinen
2020-09-24 21:55 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 11/24] x86/sgx: Add SGX enclave driver Jarkko Sakkinen
2020-09-21 9:30 ` Borislav Petkov
2020-09-21 12:09 ` Jarkko Sakkinen
2020-10-01 17:36 ` Sean Christopherson
2020-10-01 18:49 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 12/24] x86/sgx: Add SGX_IOC_ENCLAVE_CREATE Jarkko Sakkinen
2020-09-21 10:03 ` Borislav Petkov
2020-09-21 12:28 ` Jarkko Sakkinen
2020-09-21 13:51 ` Borislav Petkov
2020-09-21 19:29 ` Jarkko Sakkinen
2020-10-03 0:23 ` Haitao Huang
2020-10-03 3:24 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 13/24] x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 14/24] x86/sgx: Add SGX_IOC_ENCLAVE_INIT Jarkko Sakkinen
2020-09-21 17:35 ` Borislav Petkov
2020-09-21 18:10 ` Sean Christopherson
2020-09-21 18:27 ` Borislav Petkov
[not found] ` <20200921191658.GA24823@linux.intel.com>
2020-09-22 8:29 ` Borislav Petkov
2020-09-22 11:50 ` Jarkko Sakkinen
2020-09-22 12:56 ` Jethro Beekman
2020-09-22 14:29 ` Borislav Petkov
2020-09-23 14:47 ` Jarkko Sakkinen
2020-09-23 15:55 ` Borislav Petkov
2020-09-24 12:23 ` Jarkko Sakkinen
2020-09-22 16:29 ` Sean Christopherson
2020-09-21 19:22 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 15/24] x86/sgx: Enable provisioning for remote attestation Jarkko Sakkinen
2020-09-21 18:07 ` Borislav Petkov
2020-09-21 19:27 ` Jarkko Sakkinen
2020-09-21 19:41 ` Borislav Petkov
2020-09-21 21:26 ` Jarkko Sakkinen
2020-09-22 8:30 ` Borislav Petkov
2020-09-15 11:28 ` [PATCH v38 16/24] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-09-22 10:45 ` Borislav Petkov
2020-09-22 14:03 ` Jarkko Sakkinen
2020-09-22 14:24 ` Borislav Petkov
2020-09-23 14:52 ` Jarkko Sakkinen
2020-09-29 1:14 ` Sean Christopherson
2020-09-29 3:50 ` Jarkko Sakkinen
2020-09-29 8:35 ` Sean Christopherson
2020-09-22 16:24 ` Sean Christopherson
2020-09-22 18:02 ` Borislav Petkov
2020-09-23 15:25 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 17/24] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-09-22 15:44 ` Borislav Petkov
2020-09-23 13:20 ` Jarkko Sakkinen
2020-09-23 16:17 ` Borislav Petkov
2020-09-24 11:51 ` Jarkko Sakkinen
2020-09-24 15:57 ` Borislav Petkov
2020-09-24 20:38 ` [PATCH v38 17/24] x86/sgx: ptrace() support for the SGX driver' Jarkko Sakkinen
2020-09-24 20:40 ` Jarkko Sakkinen
2020-09-25 7:53 ` Borislav Petkov
2020-09-25 11:00 ` Jarkko Sakkinen
2020-09-25 7:51 ` Borislav Petkov
2020-09-25 11:21 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 18/24] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-09-23 22:07 ` Borislav Petkov
2020-09-24 12:09 ` Jarkko Sakkinen
2020-09-24 16:00 ` Borislav Petkov
2020-09-24 21:07 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 19/24] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 20/24] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-09-24 16:31 ` Borislav Petkov
2020-09-24 23:11 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 21/24] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-09-24 18:04 ` Borislav Petkov
2020-09-25 1:00 ` Jarkko Sakkinen
2020-09-25 8:28 ` Borislav Petkov
2020-09-27 23:37 ` Jarkko Sakkinen
2020-09-28 8:30 ` Borislav Petkov
2020-09-28 15:02 ` Jarkko Sakkinen
2020-09-25 8:39 ` Jethro Beekman
2020-09-25 11:17 ` Jarkko Sakkinen
2020-09-25 11:43 ` Jethro Beekman
[not found] ` <20200925003808.GB20333@linux.intel.com>
2020-09-25 1:04 ` Jarkko Sakkinen
2020-09-25 8:14 ` Borislav Petkov
2020-09-25 10:59 ` Jarkko Sakkinen
2020-09-28 14:36 ` Jarkko Sakkinen
2020-09-25 18:23 ` Andrew Cooper
2020-09-28 0:58 ` Jarkko Sakkinen
2020-09-28 16:44 ` Andrew Cooper
2020-09-28 18:07 ` H.J. Lu
2020-09-28 18:12 ` Andy Lutomirski
2020-09-28 18:17 ` Dave Hansen
2020-09-28 22:07 ` Jarkko Sakkinen
2020-09-28 21:56 ` Jarkko Sakkinen
2020-09-28 22:06 ` H.J. Lu
2020-09-28 22:18 ` Dave Hansen
2020-09-28 22:41 ` Andy Lutomirski
2020-09-28 23:38 ` Andrew Cooper
2020-09-29 14:10 ` Dave Hansen
2020-09-29 15:01 ` Andrew Cooper
2020-09-28 21:41 ` Jarkko Sakkinen
2020-09-28 20:42 ` Jarkko Sakkinen
2020-09-28 23:52 ` Andrew Cooper
2020-09-30 0:52 ` Jarkko Sakkinen
2020-09-28 15:43 ` Yu, Yu-cheng
2020-09-28 15:54 ` H.J. Lu
2020-09-28 16:40 ` Yu, Yu-cheng
2020-09-28 21:36 ` Jarkko Sakkinen
2020-09-28 20:56 ` Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 22/24] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-09-15 11:28 ` [PATCH v38 23/24] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-09-23 13:50 ` Borislav Petkov
2020-09-24 11:28 ` Jarkko Sakkinen
2020-09-24 15:54 ` Borislav Petkov
2020-09-15 11:28 ` [PATCH v38 24/24] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
2020-09-25 22:37 ` Sean Christopherson
2020-09-28 0:44 ` Jarkko Sakkinen
-- strict thread matches above, loose matches on Subject: below --
2020-09-15 11:04 [PATCH v38 00/24] Intel SGX foundations Jarkko Sakkinen
2020-09-15 11:05 ` [PATCH v38 10/24] mm: Add vm_ops->mprotect() 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=20200921211849.GA25403@linux.intel.com \
--to=sean.j.christopherson@intel.com \
--cc=akpm@linux-foundation.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=asapek@google.com \
--cc=bp@alien8.de \
--cc=cedric.xing@intel.com \
--cc=chenalexchen@google.com \
--cc=conradparker@google.com \
--cc=cyhanish@google.com \
--cc=darren.kenny@oracle.com \
--cc=dave.hansen@intel.com \
--cc=haitao.huang@intel.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jethro@fortanix.com \
--cc=josh@joshtriplett.org \
--cc=kai.huang@intel.com \
--cc=kai.svahn@intel.com \
--cc=kmoy@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-sgx@vger.kernel.org \
--cc=ludloff@google.com \
--cc=luto@kernel.org \
--cc=nhorman@redhat.com \
--cc=npmccallum@redhat.com \
--cc=puiterwijk@redhat.com \
--cc=rientjes@google.com \
--cc=tglx@linutronix.de \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
--cc=yaozhangx@google.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).