Re: Sourceware mitigating and preventing the next xz-backdoor

Sam James via Gdb
2024-04-09T22:24:19Z

[-- Attachment #1: Type: text/plain, Size: 1276 bytes --]

Paul Eggert <eggert@cs.ucla.edu> writes:

> On 4/9/24 14:58, Sam James wrote:
>> Meson doesn't allow user-defined functions
>
> Meson has ways to execute arbitrary user-defined code, so it's not
> immune to this sort of exploit.

To be clear - not saying it's immune. Just that it scopes the
user-defined code part to clearly defined sections.

I think it makes sense to optimise for ease of review.

>
> It's of course better (all other things being equal) to use a build
> system with a smaller attack surface. However, any surface of nonzero
> size is attackable, so I'm not convinced that Meson is significantly
> safer against a determined insider. Although the xz exploit was tricky
> and is now famous (hey! the front page of the New York Times!)
> fundamentally it was sloppy and amateurish and it succeeded only
> because xz's project management was even sloppier.
>
> Yes, we need to defend against amateurish attacks. But we shouldn't
> waste valuable developer time on defenses that won't work against
> obvious future attacks and that will likely cost more than they'll
> benefit. That's just security theater.

Right, I'm not advocating that. It's just easy to go too far the other
way too and not change anything because it won't hold up against a state
actor.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 377 bytes --]