From: "Xing, Cedric" <cedric.xing@intel.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-sgx@vger.kernel.org, linux-security-module@vger.kernel.org,
selinux@vger.kernel.org,
Bill Roberts <william.c.roberts@intel.com>,
Casey Schaufler <casey.schaufler@intel.com>,
James Morris <jmorris@namei.org>,
Dave Hansen <dave.hansen@intel.com>,
Andy Lutomirski <luto@kernel.org>,
Jethro Beekman <jethro@fortanix.com>,
"Dr . Greg Wettstein" <greg@enjellic.com>,
Stephen Smalley <sds@tycho.nsa.gov>
Subject: Re: [RFC PATCH v4 00/12] security: x86/sgx: SGX vs. LSM
Date: Wed, 10 Jul 2019 16:16:42 -0700 [thread overview]
Message-ID: <38d3b0ee-be9c-cb1a-785a-325a3ade003b@intel.com> (raw)
In-Reply-To: <20190710221638.bwnwtcozpv44ojdg@linux.intel.com>
On 7/10/2019 3:16 PM, Jarkko Sakkinen wrote:
> Just some questions on these.
>
> On Tue, Jul 09, 2019 at 10:09:17AM -0700, Sean Christopherson wrote:
>> - FILE__ENCLAVE_EXECUTE: equivalent to FILE__EXECUTE, required to gain X
>> on an enclave page loaded from a regular file
>
> One thing that I have hard time to perceive is that whether the process
> or the target object has them. So would this be in the files extended
> attribute or does process need to possess this or both?
The target object.
>> - PROCESS2__ENCLAVE_EXECDIRTY: hybrid of EXECMOD and EXECUTE+WRITE,
>> required to gain W->X on an enclave page
>
> Still puzzling with EXECMOD given that how it is documented in
> https://selinuxproject.org/page/ObjectClassesPerms. If anything in that
> document is out of date, would be nice if it was updated.
If you search for "EXECMOD" in security/selinux/hooks.c in the latest
(Linux-5.2) master, you'll find only one occurrence - at line 3702.
The logic over there, if translated into English, basically says
FILE__EXECMOD is required (on the backing file) if mprotect() is called
to request X on a private file mapping that has been modified by the
calling process. That's what Sean meant by "W->X".
EXCLAVE_EXECDIRTY is similar to EXECMOD but because of his "maximal
protection" model, LSM couldn't distinguish between "W->X" and "X->W",
hence those two are collapsed into a single case - WX in "maximal
protection".
>> - PROCESS2__ENCLAVE_EXECANON: subset of EXECMEM, required to gain X on
>> an enclave page that is loaded from an
>> anonymous mapping
>>
>> - PROCESS2__ENCLAVE_MAPWX: subset of EXECMEM, required to gain WX on an
>> enclave page
>
> I guess these three belong to the process and are not attached to file.
Correct.
ENCLAVE_EXECANON basically means the calling process doesn't care what
permissions given to enclave pages as the SIGSTRUCT alone is considered
sufficient validation. This has a security impact process wide so shall
be a process permission.
ENCLAVE_{EXECDIRTY|MAPWX} express enclave specific
requirements/behaviors and IMO shall be enclave permissions, probably
manifested as file permissions on the file containing SIGSTRUCT. Sean
was taking a shortcut to make them process scope in order to avoid
keeping the SIGSTRUCT file around, which was what I criticized as
"illogical".
> How in SELinux anyway process in the first place acquires any SELinux
> permissions? I guess getty or whatever login process can set its perms
> before setuid() et al somehow (I don't know how) because they run as
> root?
>
> /Jarkko
>
next prev parent reply other threads:[~2019-07-10 23:16 UTC|newest]
Thread overview: 156+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-19 22:23 [RFC PATCH v4 00/12] security: x86/sgx: SGX vs. LSM Sean Christopherson
2019-06-19 22:23 ` [RFC PATCH v4 01/12] x86/sgx: Use mmu_notifier.release() instead of per-vma refcounting Sean Christopherson
2019-06-20 21:03 ` Jarkko Sakkinen
2019-07-08 14:57 ` Sean Christopherson
2019-07-09 16:18 ` Jarkko Sakkinen
2019-06-19 22:23 ` [RFC PATCH v4 02/12] x86/sgx: Do not naturally align MAP_FIXED address Sean Christopherson
2019-06-20 21:09 ` Jarkko Sakkinen
2019-06-20 22:09 ` Jarkko Sakkinen
2019-06-19 22:23 ` [RFC PATCH v4 03/12] selftests: x86/sgx: Mark the enclave loader as not needing an exec stack Sean Christopherson
2019-06-20 21:17 ` Jarkko Sakkinen
2019-06-19 22:23 ` [RFC PATCH v4 04/12] x86/sgx: Require userspace to define enclave pages' protection bits Sean Christopherson
2019-06-21 1:07 ` Jarkko Sakkinen
2019-06-21 1:16 ` Jarkko Sakkinen
2019-06-21 16:42 ` Xing, Cedric
2019-07-08 16:34 ` Sean Christopherson
2019-07-08 17:29 ` Xing, Cedric
2019-07-01 18:00 ` Andy Lutomirski
2019-07-01 19:22 ` Xing, Cedric
2019-06-19 22:23 ` [RFC PATCH v4 05/12] x86/sgx: Enforce noexec filesystem restriction for enclaves Sean Christopherson
2019-06-21 1:26 ` Jarkko Sakkinen
2019-07-07 19:03 ` Sean Christopherson
2019-06-19 22:23 ` [RFC PATCH v4 06/12] mm: Introduce vm_ops->may_mprotect() Sean Christopherson
2019-06-21 1:35 ` Jarkko Sakkinen
2019-06-19 22:23 ` [RFC PATCH v4 07/12] LSM: x86/sgx: Introduce ->enclave_map() hook for Intel SGX Sean Christopherson
2019-06-21 2:28 ` Jarkko Sakkinen
2019-06-21 16:54 ` Xing, Cedric
2019-06-25 20:48 ` Stephen Smalley
2019-06-27 20:29 ` Xing, Cedric
2019-07-07 18:01 ` Sean Christopherson
2019-06-19 22:23 ` [RFC PATCH v4 08/12] security/selinux: Require SGX_MAPWX to map enclave page WX Sean Christopherson
2019-06-21 17:09 ` Xing, Cedric
2019-06-25 21:05 ` Stephen Smalley
2019-06-27 20:26 ` Xing, Cedric
2019-06-25 20:19 ` Stephen Smalley
2019-06-26 12:49 ` Dr. Greg
2019-06-19 22:23 ` [RFC PATCH v4 09/12] LSM: x86/sgx: Introduce ->enclave_load() hook for Intel SGX Sean Christopherson
2019-06-21 17:05 ` Xing, Cedric
2019-06-25 21:01 ` Stephen Smalley
2019-06-25 21:49 ` Stephen Smalley
2019-06-27 19:38 ` Xing, Cedric
2019-06-19 22:23 ` [RFC PATCH v4 10/12] security/selinux: Add enclave_load() implementation Sean Christopherson
2019-06-21 21:22 ` Xing, Cedric
2019-06-25 21:09 ` Stephen Smalley
2019-06-27 20:19 ` Xing, Cedric
2019-06-28 16:16 ` Stephen Smalley
2019-06-28 21:20 ` Xing, Cedric
2019-06-29 1:15 ` Stephen Smalley
2019-07-01 18:14 ` Xing, Cedric
2019-06-29 23:41 ` Andy Lutomirski
2019-07-01 17:46 ` Xing, Cedric
2019-07-01 17:53 ` Andy Lutomirski
2019-07-01 18:54 ` Xing, Cedric
2019-07-01 19:03 ` Xing, Cedric
2019-07-01 19:32 ` Andy Lutomirski
2019-07-01 20:03 ` Xing, Cedric
2019-07-07 18:46 ` Sean Christopherson
2019-06-25 20:34 ` Stephen Smalley
2019-06-19 22:24 ` [RFC PATCH v4 11/12] security/apparmor: " Sean Christopherson
2019-06-19 22:24 ` [RFC PATCH v4 12/12] LSM: x86/sgx: Show line of sight to LSM support SGX2's EAUG Sean Christopherson
2019-06-21 17:18 ` Xing, Cedric
2019-07-08 14:34 ` Sean Christopherson
2019-06-21 1:32 ` [RFC PATCH v4 00/12] security: x86/sgx: SGX vs. LSM Jarkko Sakkinen
2019-06-27 18:56 ` [RFC PATCH v2 0/3] security/x86/sgx: SGX specific LSM hooks Cedric Xing
2019-07-03 23:16 ` Jarkko Sakkinen
2019-07-03 23:22 ` Jarkko Sakkinen
2019-07-03 23:23 ` Jarkko Sakkinen
2019-07-06 5:04 ` Xing, Cedric
2019-07-08 14:46 ` Jarkko Sakkinen
2019-07-07 23:41 ` [RFC PATCH v3 0/4] " Cedric Xing
2019-07-08 15:55 ` Sean Christopherson
2019-07-08 17:49 ` Xing, Cedric
2019-07-08 18:49 ` Sean Christopherson
2019-07-08 22:26 ` Xing, Cedric
2019-07-07 23:41 ` [RFC PATCH v3 1/4] x86/sgx: Add " Cedric Xing
2019-07-07 23:41 ` [RFC PATCH v3 2/4] x86/64: Call LSM hooks from SGX subsystem/module Cedric Xing
2019-07-09 1:03 ` Sean Christopherson
2019-07-07 23:41 ` [RFC PATCH v3 3/4] X86/sgx: Introduce EMA as a new LSM module Cedric Xing
2019-07-08 16:26 ` Casey Schaufler
2019-07-08 17:16 ` Xing, Cedric
2019-07-08 23:53 ` Casey Schaufler
2019-07-09 22:13 ` Xing, Cedric
2019-07-10 0:10 ` Casey Schaufler
2019-07-10 0:55 ` Xing, Cedric
2019-07-10 21:14 ` Casey Schaufler
2019-07-11 13:51 ` Stephen Smalley
2019-07-11 15:12 ` Sean Christopherson
2019-07-11 16:11 ` Stephen Smalley
2019-07-11 16:25 ` Sean Christopherson
2019-07-11 16:32 ` Stephen Smalley
2019-07-11 23:41 ` Xing, Cedric
2019-07-07 23:41 ` [RFC PATCH v3 4/4] x86/sgx: Implement SGX specific hooks in SELinux Cedric Xing
2019-07-09 1:33 ` Sean Christopherson
2019-07-09 21:26 ` Xing, Cedric
2019-07-10 15:49 ` Sean Christopherson
2019-07-10 16:08 ` Jethro Beekman
2019-07-10 18:16 ` Xing, Cedric
2019-07-10 17:54 ` Xing, Cedric
2019-06-27 18:56 ` [RFC PATCH v2 1/3] x86/sgx: Add SGX specific LSM hooks Cedric Xing
2019-06-27 22:06 ` Casey Schaufler
2019-06-27 22:52 ` Xing, Cedric
2019-06-27 23:37 ` Casey Schaufler
2019-06-28 0:47 ` Xing, Cedric
2019-06-28 17:22 ` Casey Schaufler
2019-06-28 22:29 ` Xing, Cedric
2019-06-29 1:37 ` Stephen Smalley
2019-06-29 21:35 ` Casey Schaufler
2019-07-01 17:57 ` Xing, Cedric
2019-07-01 19:53 ` Casey Schaufler
2019-07-01 21:45 ` Xing, Cedric
2019-07-01 23:11 ` Casey Schaufler
2019-07-02 7:42 ` Xing, Cedric
2019-07-02 15:44 ` Casey Schaufler
2019-07-03 9:46 ` Dr. Greg
2019-07-03 15:32 ` Casey Schaufler
2019-07-07 13:30 ` Dr. Greg
2019-07-09 0:02 ` Casey Schaufler
2019-07-09 1:52 ` Sean Christopherson
2019-07-09 21:16 ` Xing, Cedric
2019-07-11 10:22 ` Dr. Greg
2019-07-15 22:23 ` Andy Lutomirski
2019-06-28 16:37 ` Stephen Smalley
2019-06-28 21:53 ` Xing, Cedric
2019-06-29 1:22 ` Stephen Smalley
2019-07-01 18:02 ` Xing, Cedric
2019-06-29 23:46 ` Andy Lutomirski
2019-07-01 17:11 ` Xing, Cedric
2019-07-01 17:58 ` Andy Lutomirski
2019-07-01 18:31 ` Xing, Cedric
2019-07-01 19:36 ` Andy Lutomirski
2019-07-01 19:56 ` Xing, Cedric
2019-07-02 2:29 ` Andy Lutomirski
2019-07-02 6:35 ` Xing, Cedric
2019-06-27 18:56 ` [RFC PATCH v2 2/3] x86/sgx: Call LSM hooks from SGX subsystem/module Cedric Xing
2019-06-27 18:56 ` [RFC PATCH v2 3/3] x86/sgx: Implement SGX specific hooks in SELinux Cedric Xing
2019-07-05 16:05 ` [RFC PATCH v4 00/12] security: x86/sgx: SGX vs. LSM Jarkko Sakkinen
2019-07-08 17:29 ` Sean Christopherson
2019-07-08 17:33 ` Xing, Cedric
2019-07-09 16:22 ` Jarkko Sakkinen
2019-07-09 17:09 ` Sean Christopherson
2019-07-09 20:41 ` Xing, Cedric
2019-07-09 22:25 ` Sean Christopherson
2019-07-09 23:11 ` Xing, Cedric
2019-07-10 16:57 ` Sean Christopherson
2019-07-10 20:19 ` Jarkko Sakkinen
2019-07-10 20:31 ` Sean Christopherson
2019-07-11 9:06 ` Jarkko Sakkinen
2019-07-10 22:00 ` Jarkko Sakkinen
2019-07-10 22:16 ` Jarkko Sakkinen
2019-07-10 23:16 ` Xing, Cedric [this message]
2019-07-11 9:26 ` Jarkko Sakkinen
2019-07-11 14:32 ` Stephen Smalley
2019-07-11 17:51 ` Jarkko Sakkinen
2019-07-12 0:08 ` Xing, Cedric
2019-07-10 1:28 ` Dr. Greg
2019-07-10 2:04 ` Xing, Cedric
2019-07-10 3:21 ` Jethro Beekman
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