Messages in this thread | | | Date | Mon, 30 Jan 2023 16:52:55 -0500 | From | "Colin Walters" <> | Subject | Re: [PATCH v3 1/2] exec: add PR_HIDE_SELF_EXE prctl |
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On Mon, Jan 30, 2023, at 5:06 AM, Christian Brauner wrote:
> The good thing is that - even if it will take a longer - that Aleksa's > patchset will provide a more general solution by making it possible for > runc/crun/lxc to open the target binary with a restricted upgrade mask > making it impossible to open the binary read-write again. This won't > break criu and will fix this issue and is generally useful.
Had to go back up thread more carefully; looking at the referenced commits now in https://github.com/cyphar/linux/commits/magiclink/open_how-reopen I do agree that that direction is the most elegant. The main downside I can think of is the potential blast radius is larger, and more nontrivial code.
But...in practice I guess today for the runc/crun type attacks today there are commonly multiple mitigations (e.g. read-only rootfs, multiple LSMs, and finally the memfd copy fallback) so we can probably wait for that patchset to land.
In short: agreed!
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