| 31 Mar 2025 |
 niko ⚡️ | By design | 20:36:02 |
 @r522:matrix.org | i'm looking at https://github.com/NixOS/nix/blob/5a8dedc45cc04a207917316c245e4993234bfbe0/src/libstore/unix/build/local-derivation-goal.cc and i don't see an allow list?
... i also don't see where io_uring is blocked though | 20:38:17 |
| @r522:matrix.org | * i'm looking at https://github.com/NixOS/nix/blob/5a8dedc45cc04a207917316c245e4993234bfbe0/src/libstore/unix/build/local-derivation-goal.cc#L1774 and i don't see an allow list?
... i also don't see where io_uring is blocked though | 20:39:05 |
| @r522:matrix.org | so i guess that's not what sets up the build sandbox | 20:39:17 |
| niko ⚡️ | No, you're right, I'm too Lix-brained, Lix has an explicit syscall list, CppNix uses (for the most part) the default seccomp profile | 20:45:13 |
| @r522:matrix.org | mhm
i will go look in lix to see where they do it then | 20:46:48 |
| @r522:matrix.org | right, yeah, they do | 20:47:22 |
| @r522:matrix.org | that being said, they don't seem to care about the exact path used for opens | 20:48:08 |
| @r522:matrix.org | so it's seccomp but not in a way that inspects paths
actually, you can't do that anyways | 20:48:35 |
| @r522:matrix.org | * so it's seccomp but not in a way that inspects paths
actually, you can't do that anyways with seccomp | 20:48:38 |
| @r522:matrix.org | so allowing io_uring operations that are equal to syscalls that are already allowed would be fine | 20:48:57 |
| @r522:matrix.org | unsure if you can set global io_uring restrictions though | 20:50:59 |
| @r522:matrix.org | mhm yeah it's per-ring | 20:51:42 |
| 1 Apr 2025 |
 @aloisw:julia0815.de | In reply to @r522:matrix.org
so allowing io_uring operations that are equal to syscalls that are already allowed would be fine The problem is that seccomp cannot do that. | 04:38:41 |
|  leona joined the room. | 08:42:50 |
| @r522:matrix.org | yeah
it wouldn't be hard to make it do that, kernel-wise (or maybe LD_PRELOAD some shim that goes and asks for an already created ring that has syscall restrictions applied already)
but i guess ultimately it doesn't Particularly matter since all you lose is the ability to run tests in the sandbox | 10:42:38 |
 K900 | In reply to @r522:matrix.org
yeah
it wouldn't be hard to make it do that, kernel-wise (or maybe LD_PRELOAD some shim that goes and asks for an already created ring that has syscall restrictions applied already)
but i guess ultimately it doesn't Particularly matter since all you lose is the ability to run tests in the sandbox There are no restrictions in io_uring | 10:47:58 |
| K900 | That's kind of the problem | 10:48:04 |
| @r522:matrix.org | there are, but it's per-ring | 10:48:33 |
| @r522:matrix.org | not globally | 10:48:38 |
| @r522:matrix.org | if there was a syscall to say "apply these restrictions to all future rings made by this process", it would be fine | 10:49:25 |
