[Starlingx-discuss] Recommended C/C++ compiler flag for security

Mon Jan 7 22:13:36 UTC 2019

On Wed, 2019-01-02 at 14:40 -0600, Victor Rodriguez wrote:
> > 
> > 
> On Wed, Jan 2, 2019 at 10:35 AM Young, Ken <Ken.Young at windriver.com>
> wrote:
> > 
> > Victor,
> > 
> > 
> > 
> > Security work is never completed.  There is always a long list of
> > inventive new vulnerabilities and a laundry list of hardening work
> > to be completed.   The vulnerability work, considering the
> > severity, is generally urgent.  Hardening work is not urgent but
> > important.  In this case, we are dealing with a hardening
> > initiative that focuses on a small area of the code.
> > 

I don't entirely agree with the hardening urgency, as hardening can
prevent vulnerabilities. The lack of reported vulnerabilities not
necessary means that software is secure, most probably is that the
software hasn't been used/tested well enough. 

Prevention tends to be more cost-effective than mitigation. I'd prefer
to treat the hardening as high priority.

> > 
> > The challenge is that these small change proposed have larger
> > implications.  As was pointed out on the gerrit reviews,
> > performance and / or functional testing is required.  My concern is
> > that we affect the timing / behaviour of stx-ha and stx-metal such
> > that they do not work together in some scenarios.  This will need
> > to be tested and is certainly larger than a sanity.
> > 

I agree, Also I think that in order to improve the discussion and
solution of these issues it would be helpful to understand the
critical/specific use cases that people is worried about and the
thresholds that we shouldn't cross. Then, find a way to measure them
and start from there.

Otherwise we will deal with a high level of ambiguity that could cause
delays on solving these issues.

> Agree, our concern on the last  TSC meeting was to come up with a
> proper framework to measure the performance impact of key changes in
> the project ( such as new compiler flags or new functionality
> options). The concern you have about timing /behavior of stx-ha and
> stx-metal is a key point that I would like to understand more, the
> idea is to improve security without affecting functionality at all
> > Also, I am wondering if there is a way to phase the effort. For
> > example, is there a way to break up the flag changes such that the
> > warnings are separated from the flags which change the compiled
> > code?  That way, we are not trying to jam everything through at
> > once.
> 
> We could came up with a V2 of the patches with just the warning flags
> and the fixes to those warnings, is that ok?

Agree with apply the warning patch first to have some progress.

> > 
> > 
> > 
> > Hope this helps.  Happy to discuss when you return from Holliday.
> 
> Sure, thanks for the feedback ( I will be fully back Monday )
> 
> > 
> > 
> > 
> > Regards,
> > 
> > Ken Y
> > 
> > 
> > 
> > From: Victor Rodriguez <vm.rod25 at gmail.com>
> > Date: Friday, December 28, 2018 at 7:34 PM
> > To: Curtis <serverascode at gmail.com>
> > Cc: "starlingx-discuss at lists.starlingx.io" <starlingx-discuss at lists
> > .starlingx.io>
> > Subject: Re: [Starlingx-discuss] Recommended C/C++ compiler flag
> > for security
> > 
> > 
> > 
> > 
> > 
> > On Fri, Dec 21, 2018, 07:08 Curtis <serverascode at gmail.com wrote:
> > 
> > 
> > 
> > 
> > 
> > On Thu, Dec 20, 2018 at 3:47 PM Victor Rodriguez <vm.rod25 at gmail.co
> > m> wrote:
> > 
> > Hi StarlingX community
> > 
> > We can all agree that security is an important feature to be taken
> > into consideration in any SW project. In the aim of improving the
> > security of the StarlingX project, we have been taking the task to
> > propose the use of some compiler flags that prevent and detect some
> > security holes, especially by buffer overflow that could lead into
> > ROP
> > attacks.
> > 
> > The list of flags that we are proposing are :
> > 
> > Stack-based Buffer Overrun Detection:    CFLAGS=”-fstack-protector-
> > strong”
> > 
> > Fortify source:                          CFLAGS="-O2
> > -D_FORTIFY_SOURCE=2"
> > Format string vulnerabilities:          CFLAGS="-Wformat -Wformat-
> > security"
> > Stack execution protection:              LDFLAGS="-z noexecstack"
> > Data relocation and protection (RELRO): LDLFAGS="-z relro -z now"
> > 
> > 
> > These are being analyzed in the following Gerrit reviews (thanks a
> > lot
> > for all the good feedback)
> > 
> > https://review.openstack.org/#/c/623608/
> > https://review.openstack.org/#/c/623603/
> > https://review.openstack.org/#/c/623601/
> > https://review.openstack.org/#/c/623599/
> > 
> > As requested in the Gerrit reviews, there is a proper need to first
> > understand what these compiler flags do and what is the impact they
> > have at the functional and performance area of the project. This is
> > a
> > preliminary report, we will be following up with a test plan for
> > functional & performance test plans for the services as a next
> > step.
> > This report includes:
> > 
> > * Detailed description of what the compiler flag does
> > * Code example that shows how does it work to prevent attacks
> > * If there is a change in the binary, we create a microbenchmark
> > that
> > shows us how the flag impact the performance
> > 
> > https://github.com/VictorRodriguez/hobbies/tree/master/c_programing
> > _exercises/cflags_security
> > 
> > As a result of the microbenchmark, the performance impact is not
> > relevant ( less than 1% ) using an Ubuntu x86 system ( GCC 5 )
> > (more
> > details on the HW and SW specification upon requests)
> > 
> > The areas of the code we are suggesting on the patches are:
> > 
> > * stx-ha
> > * stx-metal
> > * stx-nfv
> > * stx-fault
> > 
> > We do take care that these flags are not breaking the following
> > areas
> > after being applied.
> > 
> > * Build process of the image
> > * Sanity test cases after the image is created
> > (Ada can give more details on the sanity report of the image
> > generated
> > with these flags)
> > 
> > If running the sanity tests are not enough to prove that a change
> > in
> > compiler flags do not affect functionality, please gave us the
> > right
> > path to follow.
> > 
> > As mentioned before, this is a preliminary report, and that we will
> > be
> > following up with a test plan for functional & performance test
> > plans
> > for the services as a next step.
> > 
> > Hope this email helps to clarify some questions related to the
> > flags
> > and start the follow-up discussion.
> > 
> > 
> > 
> > Thanks for the context Victor, it's very helpful to me.
> > 
> > 
> > 
> > Hi Curtis, glad it helps, it was fun to do the research
> > 
> > 
> > 
> > One thing I want to mention is something the Kata Containers team
> > was talking about at the Berlin OpenStack summit, which is when
> > many small performance hits start to add up. They have to be
> > careful to ensure they don't have a bunch of smallish looking
> > changes that add up to a large performance hit over a longer period
> > of time.
> > 
> > 
> > 
> > You are right, it's a valid point that we need to take care too
> > 
> > 
> > 
> > Overall I'm sure the StarlingX project would like to have some
> > performance testing, if we don't already, though that can be
> > challenging for an open source project. I had mentioned OPNFV's
> > Functest and related projects on the TSC call, but now seeing which
> > components are affected I'm not sure that would be directly
> > helpful. I look forward to further discussions around this area.
> > 
> > 
> > 
> > Thanks for let me know that, I will take a look at OPNFV's functest
> > and other projects before the next TSC of 2019
> > 
> > 
> > 
> > I will do my best to came up with a proposal for a better
> > performance testing.
> > 
> > 
> > 
> > Thanks
> > 
> > 
> > 
> > Victor Rodriguez
> > 
> > 
> > 
> > Thanks,
> > 
> > Curtis
> > 
> > 
> > 
> > 
> > Regards
> > 
> > Victor Rodriguez
> > 
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> > s
> > 
> > 
> > 
> > --
> > 
> > Blog: serverascode.com
> 
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