firejail VS src

bubblewrap is designed as a low-level too. There is nothing quick and dirty about it. It disallows everything by default and you have to be explicit about what you want to share with the host. If your application needs complex permissions/resources, then you will need to have a complex bubblewrap command line.

Once you have figured out which permissions/resources you need for a given program, you can wrap the command line invocation in a shell script.

If you want other people to do the work of defining permissions/resources, then have a look at firejail: https://github.com/netblue30/firejail

Firejail is cool: https://github.com/netblue30/firejail

Linux namespaces/cgroups but nowhere near as heavy as Docker.

I use it when I want to limit the memory of a Python script:

```

Firejail can also be a useful option, though no good if you're on Mac https://firejail.wordpress.com/

Uses the same Linux primitives as docker etc, but can be a bit more ergonomic for this use case

Firejail, Flatpak (which uses Bubblewrap under the hood), and Snap (which uses AppArmor) all use the same underlying technology: Linux namespaces.

This question comes up a lot, and has been answered here: https://github.com/netblue30/firejail/wiki/Frequently-Asked-...

TL;DR: Firejail has much more comprehensive features than Flatpak (Bubblewrap). Firejail also has more comprehensive network support, support for AppArmor and SELinux, and easier seccomp filtering.

Compared to Snap (which uses AppArmor), Firejail is compatible with AppArmor and again goes above and beyond with a lot of additional features.

Wonderful little tool, too bad you must chain various exec calling tools to get cgroups (a bit akin to `ionice ... nice ... cmd`) and Linux users namespaces can't allow UNIX sockets while preventing network access (I think?).

Migrated from Firejail when its complexity annoyed me too much and I hit https://github.com/netblue30/firejail/issues/3001 (Firejail doesn't like parens or brackets in --put/--get parameters) to a badly NIH version using bwrap and bash to have "profiles":

Firejail does this. The profile database is the two "profile" directories in https://github.com/netblue30/firejail/tree/master/etc

What do you mean by a Firefox container? Do you mean FireJail?

The OpenBSD project released 7.4 of their OS on 16 Oct 2023 as their 55th release 💫

Well since https://www.openbsd.org/ still says

> Only two remote holes in the default install, in a heck of a long time!

I'm assuming not, but I could always be mistaken.

> building a cat from scratch

> That would be an interesting project.

Here is the source code of the OpenBSD implementation of cat:

> https://github.com/openbsd/src/blob/master/bin/cat/cat.c

and here of the GNU coreutils implementation:

> https://github.com/coreutils/coreutils/blob/master/src/cat.c

Thus: I don't think building a cat from scratch or creating a tutorial about that topic is particularly hard (even though the HN audience would likely be interested in it). :-)

> I don't know how they define `MAX`, but I'm guessing it's a typical "a>b?a:b"

Indeed: https://github.com/openbsd/src/blob/master/sys/sys/param.h#L...

> Then `SYS_kbind` seems to be a signed int.

It's an untyped #define: https://github.com/openbsd/src/blob/master/sys/sys/syscall.h...

I believe your whole analysis is correct, that running an elf file with an openbsd.syscalls entry with .sysno > INT_MAX will allow an out-of-bounds write.

I can reproduce it. And this is the commit that causes the issue: https://github.com/openbsd/src/commit/d21788ce70be80e9c4ed0c52c149e01147c4a823

This doesn’t really change your conclusion, but I think that’s the wrong file. This is the real doas afaict: https://github.com/openbsd/src/blob/master/usr.bin/doas/doas...

Still just a tidy 1072 lines in that folder though.

I spent 5 minutes staring at your file trying to understand how on earth it does the things in the man page, but of course it doesn’t.

OpenBSD developers are making serious effort to kill off indirect syscalls, the base system is completely clean, take a look at the work Andrew Fresh did to adapt Perl. He write a complete syscall "dispatcher" or emulator for the Perl syscall function so that it calls the libc stubs.

https://github.com/openbsd/src/commit/312e26c80be876012ae979...

The ports tree is also being cleansed of syscall(2) usage, until they're all gone.

msyscall, pinsyscall, recent mandatory IBT/BTI, xonly. OpenBSD is making waves, but people aren't really seeing them yet.