oss-sec mailing list archives

Re: Malicious commits to Linux kernel as part of university study


From: r00t4dm <r00t4dm () gmail com>
Date: Fri, 23 Apr 2021 01:46:15 +0800

Hello,

This case demonstrates that the possibility of a supply chain attack is
very high.
If the supply chain attack is sophisticated enough, this case may succeed.
e.g:

One day I committed some code, This code is a normal function.
After Five days, I committed some code, This code also is a normal function.

...

After three month, I committed it dozens of times,  But These committed
code together to form a vulnerability.
I don't know how to better guard against this kind of attack method,  Just
only rely on Human code review?

r00t4dm

Cloud-Penetrating Arrow Lab of Meituan Corp Information Security Department


Ariadne Conill <ariadne () dereferenced org> 于2021年4月23日周五 上午1:23写道:

Hello,

On Thu, 22 Apr 2021, David A. Wheeler wrote:

Peter Bex:
The university of Minnesota has been banned from making any commits to
the Linux kernel after it was found out they'd been submitting bogus
patches to the LKML to knowingly introduce security issues:
https://lore.kernel.org/linux-nfs/YH%2FfM%2FTsbmcZzwnX () kroah com/

I support research, but I personally think this work goes way beyond any
ethical boundaries.
While I don’t know if it’s *illegal* (I’m not a lawyer!), it seems clear
to me that these
U of MN researchers were conducting experiments on people without their
prior consent.
In the US, experiments on people without their consent is generally
forbidden.
These researchers did their experiment *before* even consulting their
Institutional Review Board (IRB),
a *huge* no-no, and then their IRB approved the non-consensual
experiment anyway (!!!).

GregKH’s response to this attack from the U of MN here:
https://lore.kernel.org/linux-nfs/YH%2FfM%2FTsbmcZzwnX () kroah com/
which reads in part:
Our community welcomes developers who wish to help and enhance Linux.
That is NOT what you are attempting to do here...
Our community does not appreciate being experimented on...

More discussion: https://news.ycombinator.com/item?id=26887670

Peter Bex:
I don't know the scope of this research, but it could involve other OSS
projects, now or in the future, as well.  Hence this e-mail.  If you
feel
it's spam or needless drama, feel free to ignore.

Since the researchers failed to get prior consent from the people
being experimented on, I don’t think we can presume ethical behavior.
I have no faith that these researchers limited their attacks.
I hope they did, but I think we can take more proactive measures.

I used the following shell command to search for potentially-concerning
commits in git:

git shortlog --summary --numbered --email | grep -E '(wu000273|kjlu|@
umn.edu)'

I recommend other OSS projects do something similar, just in case, unless
we can have better verification that no other OSS projects were attacked.
I welcome improved methods to find concerning proposals or patches;
this is just a quick attempt to detect potential damage.

The paper says that they used throwaway Gmail accounts to submit the
patches.  Frustratingly, they have not identified which patches they
succeeded in landing in that paper.

However, the paper also claims that they generated these "hypocrite"
commits using an LLVM-based static analysis tool.

Which means the work introduced by Aditya is likely directly related to
this experiment, since it has the same "feel" to it.

By mining the LKML archive, it may be possible to find the original set of
patch submissions by searching for similar keywords as the messages from
Aditya.  If somebody can do that, then we would be able to determine at
least some of the emails likely to have originated the patches.

Ariadne

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