[ruby-core:101179] Spectre Mitigations

[ruby-core:101179] Spectre Mitigations

[Amel]

Hi there!

I've already asked this question in the ruby-talk mailing list and it 
was hinted at that ruby-core could be the better place to ask, so here's 
my question.

Are there any mitigations in Ruby for the Spectre security 
vulnerability? Maybe in the interpreter itself or a function which is 
similar to the lfence-instruction.
If there isn't, are there any mitigations planned?

Cheers,

Amel

[ruby-core:101180] Re: Spectre Mitigations

[Chris Seaton]

I wouldn’t recommend using Ruby to run in-process untrusted code in the first place. Are people doing that?

Chris

> On 1 Dec 2020, at 15:32, Amel <amel.smajic@student.tugraz.at> wrote:
> 
> Hi there!
> 
> I've already asked this question in the ruby-talk mailing list and it was hinted at that ruby-core could be the better place to ask, so here's my question.
> 
> Are there any mitigations in Ruby for the Spectre security vulnerability? Maybe in the interpreter itself or a function which is similar to the lfence-instruction.
> If there isn't, are there any mitigations planned?
> 
> Cheers,
> 
> Amel
> 
> 
> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>

[ruby-core:101181] Re: Spectre Mitigations

[Amel]

Trusted code can potentially be vulnerable to Spectre attacks, as branch 
prediction on modern processors occurs in all code where there are 
branches. The question is how can I stop security critical branches from 
being executed out-of-order and thus protect my trusted code?

Amel

On 01.12.20 16:44, Chris Seaton wrote:
> I wouldn’t recommend using Ruby to run in-process untrusted code in the first place. Are people doing that?
>
> Chris
>
>> On 1 Dec 2020, at 15:32, Amel <amel.smajic@student.tugraz.at> wrote:
>>
>> Hi there!
>>
>> I've already asked this question in the ruby-talk mailing list and it was hinted at that ruby-core could be the better place to ask, so here's my question.
>>
>> Are there any mitigations in Ruby for the Spectre security vulnerability? Maybe in the interpreter itself or a function which is similar to the lfence-instruction.
>> If there isn't, are there any mitigations planned?
>>
>> Cheers,
>>
>> Amel
>>
>>
>> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
>> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>
>
> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>

[ruby-core:101182] Re: Spectre Mitigations

[Chris Seaton]

If you really do want to add barriers to your code, a one-line C extension with a full barrier instruction in it would be easy to write and would be the only way at the moment.

Chris

> On 1 Dec 2020, at 16:05, Amel <amel.smajic@student.tugraz.at> wrote:
> 
> Trusted code can potentially be vulnerable to Spectre attacks, as branch prediction on modern processors occurs in all code where there are branches. The question is how can I stop security critical branches from being executed out-of-order and thus protect my trusted code?
> 
> Amel
> 
> On 01.12.20 16:44, Chris Seaton wrote:
>> I wouldn’t recommend using Ruby to run in-process untrusted code in the first place. Are people doing that?
>> 
>> Chris
>> 
>>> On 1 Dec 2020, at 15:32, Amel <amel.smajic@student.tugraz.at> wrote:
>>> 
>>> Hi there!
>>> 
>>> I've already asked this question in the ruby-talk mailing list and it was hinted at that ruby-core could be the better place to ask, so here's my question.
>>> 
>>> Are there any mitigations in Ruby for the Spectre security vulnerability? Maybe in the interpreter itself or a function which is similar to the lfence-instruction.
>>> If there isn't, are there any mitigations planned?
>>> 
>>> Cheers,
>>> 
>>> Amel
>>> 
>>> 
>>> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
>>> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>
>> 
>> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
>> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>
> 
> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>

[ruby-core:101185] Re: Spectre Mitigations

[Lee Hambley]

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The mitigations have been put into place at the OS level [0], it is quite
far "below" the level of scripting languages such as Ruby.

I don't recall which toolchain Ruby is built with, but it is possible to
add toolchain specific annotations to the sources to guard critical
sections on top of that. [1] [2] [3]

[0]: https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/spectre.html
[1]:
https://www.phoronix.com/scan.php?page=news_item&px=GCC-8-Spectre-Mitigation-Lands
[2]: https://devblogs.microsoft.com/cppblog/spectre-mitigations-in-msvc/
[3]: https://llvm.org/docs/SpeculativeLoadHardening.html

Lee Hambley
http://lee.hambley.name/
+49 (0) 170 298 5667


On Tue, 1 Dec 2020 at 17:05, Amel <amel.smajic@student.tugraz.at> wrote:

> Trusted code can potentially be vulnerable to Spectre attacks, as branch
> prediction on modern processors occurs in all code where there are
> branches. The question is how can I stop security critical branches from
> being executed out-of-order and thus protect my trusted code?
>
> Amel
>
> On 01.12.20 16:44, Chris Seaton wrote:
> > I wouldn’t recommend using Ruby to run in-process untrusted code in the
> first place. Are people doing that?
> >
> > Chris
> >
> >> On 1 Dec 2020, at 15:32, Amel <amel.smajic@student.tugraz.at> wrote:
> >>
> >> Hi there!
> >>
> >> I've already asked this question in the ruby-talk mailing list and it
> was hinted at that ruby-core could be the better place to ask, so here's my
> question.
> >>
> >> Are there any mitigations in Ruby for the Spectre security
> vulnerability? Maybe in the interpreter itself or a function which is
> similar to the lfence-instruction.
> >> If there isn't, are there any mitigations planned?
> >>
> >> Cheers,
> >>
> >> Amel
> >>
> >>
> >> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org
> ?subject=unsubscribe>
> >> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>
> >
> > Unsubscribe: <mailto:ruby-core-request@ruby-lang.org
> ?subject=unsubscribe>
> > <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>
>
> Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>
>

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