Comment by loeg
It probably uses OS sandboxing primitives already.
It probably uses OS sandboxing primitives already.
No, that doesn't follow. That only means the networking and parsing functions can't be sandboxed in the same process that drops new root-owned files. C and C++ services have been using subprocesses for sandboxing risky functionality for a long time now. It appears Apt has some version of this:
https://salsa.debian.org/apt-team/apt/-/blob/main/apt-pkg/co...
That's true; you can't usefully sandbox apt as a whole, but, because it verifies the signatures of the packages it downloads, you could usefully sandbox the downloading process, and you could avoid doing any parsing on the package file until you've validated its signature. It's a pleasant surprise to hear that it already does something like this!
In normal operation, apt has to be able to upgrade the kernel, the bootloader, and libc, so it can't usefully be sandboxed except for testing or chroots.