Commit Graph
84 Commits
Author SHA1 Message Date
Raito BezariusandTom Hubrecht c493fb668e nix/daemon: consider supplementary groups during authentication
Two things happens here:

- we consider supplementary groups that are known for authentication,
fixes #968.

- we check supplementary groups if they are our build users group and
throw an error if they are (new behavior).

Nonetheless, we did not remove the ability for `matchUser` to recurse
and check for groups that the user may have but the connection might not
have communicated as part of their groups, i.e. if a process reduces its
list of groups via a call to setgroups, it will still be authorized.
This will come in another commit.

The authorization NixOS test has been extended with a store ping test
running in systemd with DynamicUser=true *AND* a supplementary group in
allowed-users.

Co-authored-by: Tom Hubrecht <github@mail.hubrecht.ovh>
Change-Id: I25b2b8304d66a04651cea523b5585a5d15ceebe8
Signed-off-by: Raito Bezarius <raito@lix.systems>
2026-01-28 08:24:24 +00:00
Raito Bezarius 63871751ce linux/cgroups: rename cgroups to nix-build@$drvHash-$uid
The prior use of the UID is uninteresting in general for consumers who
wants to learn things about _what_ the build is, not what is the UID of
the build user running it.

Achieving this with a place where a mapping between cgroup names and
build requests are maintained is non trivial because there's no "global"
daemon that keeps track of this information and such a daemon would
require a persistent location to track this.

Rather than solving that, we will just encode the derivation hash inside
the cgroup name. Userspace can simply pull this apart and query Nix to
obtain the original corresponding derivation for more information.

This provides userspace with a way to map cgroup names to pnames for
example. Going further, if you have a map between attribute paths and
derivation hashes, you can power a database of cgroup metrics per
attribute paths by combining all of that.

In addition to this rename, we adopt a systemd-ish convention for
template units (`@`).

As a result, userspace tooling that will scrape cgroup metrics will
discover a consistent path as long as they filter out the UID part,
especially in context of Id6c458aad30eaa08c3609ac8280a7dde8e8f3cf9
change.

This problem is tracked under #1073.

Change-Id: I238d0568a3e4b1ff3057781c0639528d666b4d37
Signed-off-by: Raito Bezarius <raito@lix.systems>
2026-01-04 18:23:32 +00:00
eldritch horrors 521b42866d nix/daemon: socket-activate single connections
the cgroups experimental feature does not work properly without this
because we do not stop subdaemons when the main daemon is shut down.
systemd needs the assigned cgroups to be empty to restart the daemon
and thus cannot cleanly restart the daemon if any connections exist.
starting a fresh unit for each connection creates a new cgroup every
time instead of sharing any delegations and thus solves the problem.

fixes #1030

Change-Id: Id6c458aad30eaa08c3609ac8280a7dde8e8f3cf9
2025-12-20 15:09:23 +00:00
Justin !andTom Hubrecht 32d7c02b96 nixpkgs: bump to 25.11
This bump nixpkgs input to 25.11 and fix the two warnings that were
coming with the update:

1. `pkgs.system` => `pkgs.stdenv.hostPlatform.system`
2. `runCommandNoCC` => `runCommand`

also:

1. remove cppnix 2.3 compat tests (cppnix 2.3 is officially dead now)
2. remove lowdown 1.3 compat tests (nixpkgs no longer carries it)

Co-authored-by: Tom Hubrecht <github@mail.hubrecht.ovh>

Change-Id: I78526b5d8992a6c63ecd7f0c7c1fa6346a6a6964
2025-12-17 20:59:59 +01:00
eldritch horrors 20ba2b49fb testing: mock ssh during nix-copy prompt test
we don't need full ssh, we only need to know something makes it onto the terminal.

Change-Id: Ic31808e10e1b876b35d0dbdeee0b5ede7b5b9883
2025-10-17 15:13:37 +02:00
Alois Wohlschlager 91bf54d726 flake: update nixpkgs input
Without https://github.com/NixOS/nixpkgs/pull/434761 evaluation of the
`nixpkgsLibTests` will fail in CI with recent enough Lix, due to reliance on
the TOML integer saturation bug.

Reported-by: Sergei Zimmerman <sergei@zimmerman.foo>

Change-Id: I6a6a6964838009d2c525f67035f84072fdfad988
2025-09-07 16:50:37 +02:00
eldritch horrors ae3b8e58c3 libstore: chown build dirs with --keep-failed
although we only chown if the build was requested by a local daemon
user. daemonless invocations will not chown as they do not have to.
remote builds *can* chown to the remote builder user, but that does
not seem to happen (for some reason keep-failed is not propagated).

Change-Id: Ic0ead406b38b4ca0556fec42d84888efa25123bf
2025-07-17 15:05:32 +02:00
Raito Bezarius 286aa409b2 Revert "libstore/build: automatic clean up of unsuccessfully built scratch outputs"
This reverts commit 42e2bd045c
because this is the root cause of the critical correctness bug.

Change-Id: Ia2360e24650a923034de72ffc193ecb73470cc48
2025-06-29 21:26:36 +02:00
Emily e1ccbe9abd daemon: prefer daemon stores for nix-daemon --stdio
Using `AllowDaemon::Disallow` here broke `ssh-ng://` remote builds in
multi‐user setups where the remote builder user does not have write
access to the store, now that the automatic store selection logic
has changed. Switch to the default behaviour for this path to fix that.

This causes `ssh-ng://` builds to use the daemon by default on the
remote end, even as `root`. I think this is desirable, as the previous
change already made `ssh://` behave this way, and the pitfalls of
local stores apply to remote builds too. For instance, there were
persistent `ulimit` issues on the NixOS Hydra macOS builders that were
resolved by forcing use of the daemon, and I believe the Linux builders
also go through the daemon these days due to using non‐`root` SSH
users. I believe that the `root` vs. non‐`root` difference is just
as confusing for remote builds as it is for local ones.

`ssh-ng://root@builder?remote-store=local` can be used to revert back
to the previous default if necessary.

Closes: #884
Fixes: 9a59106c17
Change-Id: I6a6a696410f46cd3f2f5a94073ea924ad45dc99c
2025-06-29 01:14:07 +01:00
Emily 3cfce7b37e tests: add test for bug with remote builds as non‐root user
Change-Id: I6a6a696420847c1f47f79269be6b63108ab63afa
2025-06-28 22:15:26 +01:00
Raito Bezariusandeldritch horrors 9a59106c17 libstore: NIX_REMOTE=auto tries the daemon socket *then* direct access
In the past, it tried direct access if it *could* [1] perform direct
access.

This solves a bunch of errors people had when they tried the cgroup
feature and their scripts did not pass NIX_REMOTE=daemon manually
(nixos-rebuild-ng, home-manager activation from a root systemd unit,
etc.)

To avoid looping infinitely while receiving daemon connections, we
forcibly change the store URI when forking for a subdaemon to do direct
access automatically, this doesn't break forward usecases where you
point a daemon to another socket because we only change NIX_REMOTE="",
NIX_REMOTE=daemon, NIX_REMOTE=auto to a local and direct access.

All these usecases would end up infinitely looping no matter what
settings are set, because we are also responsible for creating the
daemon socket.

[1]: this happened all the time if you were `root`.

Related: https://github.com/NixOS/nixpkgs/pull/415701
Change-Id: I783fc795a9c2ee25b3d9f44f453f8f94b063371f
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-06-25 14:59:58 +00:00
Raito Bezarius 42e2bd045c libstore/build: automatic clean up of unsuccessfully built scratch outputs
When a build fails, its scratch output paths are not cleaned up.

Until recently, this was deemed not a problem but as part of the effort
to harden the Nix builds and protect these paths against being part of a
staged attack (race conditions, etc.), we automatically cleanup after
failed builds.

Fixes CVE-2025-52992.

Change-Id: I58481b1cc83826298b9d80d37fecf81f117ccb09
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-06-24 10:49:49 +00:00
a959290f41 libstore: use pasta for FODs if available
This allows using a userspace program, pasta, to handle comms between
the build sandbox, and the outside world; allowing for full isolation
including the network namespace, closing the "fixed-output derivation
talks to the host over an abstract domain socket" hole for good.

Fixes CVE-2025-46416.

Co-Authored-By: Puck Meerburg <puck@puckipedia.com>
Change-Id: Ifd499b7dbb3784600a6e842fede65fc031ff9f15
2025-06-24 10:49:49 +00:00
Raito BezariusandMaximilian Bosch cd129186ea libstore/s3: fulfill with PutObjectOutcome instead of HeadObjectOutcome
This was probably a typo introduced in
7453e2979f.

Unfortunately, AWS SDK is so well made that this typo became an assert
error in production.

AWS Outcome constructors contains
```
            // Move error from other type of outcome
            template<typename RT, typename ET,
enable_if_t<!std::is_convertible<RT, R>::value &&

std::is_convertible<ET, E>::value, int> = 0>
```

which means that when:

* RT → R is not possible (e.g. PutObjectOutcome → HeadObjectOutcome)
* ET → E is possible (e.g. S3Error → S3Error)

Then, we will instantiate the error-moving outcome constructor which
asserts `!o.success`… Though, the original outcome indeed succeeded.

Change-Id: I3809514ae0648e8c02b0f93fa64d91115a091cd9
Co-authored-by: Maximilian Bosch <maximilian@mbosch.me>
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-06-22 19:45:53 +00:00
Raito Bezarius 87d99da6ca libutil/cgroup: ensure that cleanup takes place even under interruptions
When Ctrl-C is sent to the workload, even across remote builds, the
whole process possess a global flag `_isInterrupted` which is checked in
certain filesystem operations, cancelling them, e.g. writeFile will
write nothing under interruption unwinding.

In addition, if any operation throws an exception before we `rmdir` the
cgroup, we may leave it hanging while we remove the state record.
Therefore, we put the final cleanup in a block.

In practice, reading statistics could lead to failures.

Control groups cleanups are critical though and should always be
performed.

Change-Id: I48fa87317b6a9f6663559bc8fa5f8a897f37011e
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-06-17 22:20:37 +02:00
1e34c37477 flake/inputs: 24.11-small -> 25.05-small
We upgrade to 25.05 release, which contains the curl commit
https://github.com/curl/curl/commit/5fbd78eb2dc4afbd8884e8eed27147fc3d4318f6
done in
https://github.com/NixOS/nixpkgs/pull/396200#issuecomment-2795944006.

This fixes HTTP transfers generating arbitrary errors and possibly
failing unusually.

Users who are already depending on 25.05-small or a recent unstable
already had the fix.

Special mention to the Linux kernel who gave me the opportunity to get
on a 24 hours bisection side quest to fix the local release engineering
test.

Special thanks to everyone who had to endure me ranting.

Change-Id: I866caf65d5ea103f1fa5eccd57df8031c9eacda0
Co-authored-by: eldritch horrors <pennae@lix.systems>
Co-authored-by: helle <helle@h3l.li>
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-06-13 18:15:47 +00:00
a527bb251a libstore/build: cgroup delegation to sandbox
We offer full cgroup delegation to our sandbox now, required for running
containers inside the sandbox.

To run systemd-nspawn or containers managers inside the sandbox, there
is a need for one extra ingredient now: control over your own cgroup
subtree inside the sandbox.

If, in addition, you need multiple UIDs, for e.g. rootless usecases, you
need to run with the `uid-range` system feature.

Therefore, when the daemon or Nix runs under the right condition, e.g.
systemd-style delegation of the cgroup subtree while placing the
nix-daemon in a supervisor sub-cgroup, we create a new sub-cgroup for
each build based on the build UID and delegate that sub-cgroup to the
builder's process.

Additionally, `uid-range` always request the `cgroups` feature now, as
`uid-range` builds would probably always benefit from having cgroups
delegated, but the converse is not true.

Inspired from https://github.com/NixOS/nix/pull/11412 with a different
design that does not use function-local statics to derive the root
cgroup.

Co-authored-by: Linus Heckemann <git@sphalerite.org>
Co-authored-by: Parker Hoyes <contact@parkerhoyes.com>
Change-Id: Ic8947c5adaf4b5bbd153386e05fad65a935274fa
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-06-10 20:50:00 +02:00
Raito Bezarius 1783d5b348 libstore/build: drop cgroups experimental feature
We drop it to re-introduce it via the concept of build context which
will control in which cgroup a certain build should be spawned.

Change-Id: I4b4705d768129a6d7c0f061dc2163ba116088b18
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-06-10 16:00:51 +00:00
eldritch horrors fca0a30470 libstore: remove pre-2.18 protocols
the old protocols are largely untested, mostly unused, and have design
problems that make the RPC transition a lot harder, if not impossible.
in theory we could ship a transparent protocol-converting proxy that'd
isolate the daemon itself from old protocol versions, but that's a lot
of code to maintain for presumably little gain or even no gain at all.

Change-Id: I4c3f3bb34d39044f6aeb07c10caaf13b8340a220
2025-06-02 22:43:24 +00:00
Raito Bezarius 0dd8bf6c1c libstore/ssh: remove echo started check
The pre-flight `echo started` check over SSH was originally added in
577ebeaefb. As it is usual with these old
commits, understanding why is there a need for something is difficult.

The closest thing would be
> Fix a race starting the SSH master. We now wait synchronously for
> the SSH master to finish starting. This prevents the SSH clients
> from starting their own connections.

But, we removed SSH connection sharing, so this does not apply anymore.

Nonetheless, we believed this check was meant as a way to catch obvious
misconfigurations or SSH failures early, before handing off to
`nix-store`. However, this approach was not fruitful: it assumes the
remote has a `bash`-compatible shell, `echo` behaves in a standard way,
and no `ForceCommand` interferes—all of which are unreliable assumptions
in practice.

While the intent was to provide slightly better diagnostics (e.g. in
case of SSH hanging or returning an interactive shell), in practice it
does not meaningfully catch or improve real failure cases. The
underlying protocol or engine can and should handle those errors more
robustly anyway.

In contrast, this check *does* break several legitimate workflows,
including:

* remote builders using `ForceCommand` wrappers (e.g.
`nix-remote-build`-style setups), see
<https://discourse.nixos.org/t/wrapper-to-restrict-builder-access-through-ssh-worth-upstreaming/25834/15>,

* SSHing into minimal environments lacking `bash` (e.g. initrd,
busybox-based systems),

* configurations that don’t default to POSIX-like shells, e.g., nushell
enthusiasts.

As such, we’re removing this code. Protocol mismatch errors and SSH
failures can be rethought and handled more structurally elsewhere in the
engine.

Change-Id: I187f6881375d42ef83987a13a350c97964bbdb30
Signed-off-by: Raito Bezarius <raito@lix.systems>
2025-05-18 18:45:26 +02:00
kfearsoffandLix Systems Gerrit 8310367859 Merge "releng: add local environment" into main 2025-05-09 09:05:55 +00:00
KFearsoffandjade 3f811a415b releng: add local environment
This takes the first baby steps towards resolving #765. This first
test/workflow isn't the most useful thing ever, because it doesn't
test the code path for building the manual. Still, it does a decent job
at testing the basic git workflow, and the upload functionality.

Change-Id: I16dd3a39addd6308ad3eb37c2e3dc3466584a4e3
2025-05-09 00:01:22 +00:00
K900andeldritch horrors 227e4d349f libstore/ssh: fix the SSH connectivity check with non-POSIXy shells
SSH runs the command provided to it in the user's login shell.
That's a feature and is impossible to bypass (trust me, we tried).

The previous implementation of `echo started; nix-store --stdio`
broke with shells that treat `;` differently, e.g. nushell,
which eats the output of everything but the last command in a chain.

In the more general case, this means that a sufficiently weird shell
can do _anything_ it wants to the command we pass via SSH, so
we're forced to rely on as little functionality as possible.

The subset we're hereby settling on is just "running `bash` runs bash".
We then run bash, in non-interactive mode, which gives us a somewhat
consistent environment do to things in.

This whole thing is extremely cursed, but fixing it _correctly_
requires pretty much entirely rewriting how remote stores work,
and I'm not doing that right now.

Fixes #805.

Change-Id: Icac846e8cd821cbca91860ddaa0f657b4317dbf8
Co-authored-by: eldritch horrors <pennae@lix.systems>
2025-04-26 13:46:16 +03:00
eldritch horrors f92235e1d2 libstore: stop using ssh connection sharing
our implementation is mostly unused, completely untested, and simply
breaks when users configure connection sharing independently. we can
safely delete this "feature" and inherit user configuration instead.

also have the remote build test check that connection sharing works.

fixes #304, fixes #644

Change-Id: Iea44cc0f8e51a1d231ad186a95c7e310bbfeb303
2025-04-21 13:43:44 +00:00
Julian Stecklina 0e59e5b308 libfetchers: ensure that lastModified is a uint64_t
When lastModified comes via inputFromAttrs it ends up as string in the
Attrs map. This results in:

error: input attribute 'lastModified' is not an integer

Fix by handling it like revCount, which already does the right thing.
If added a test and confirmed that it catches the issue.

Also kudos to alexander.sieg@cyberus-technology.de for helping with
debugging this!

Change-Id: I8378fcaea986d798cb8458d4e6e15c2a92c2520a
2025-03-13 09:34:59 +01:00
Artemis TosiniandJade Lovelace 445b7c7d8a flake: Use nixpkgs 24.11
nixpkgs 24.11 changes how we access xonsh yet again
and updates clang.

Unfortunately, clang 18 produces significantly more
warnings on existing code that is challenging to fix.
Make sure that doesn't error when we're running
`-Werror` builds.

n.b. I had to change the "SSL certificate problem: self-signed
certificate" to the old error prior to the improved libcurl errors,
since what is presumably a difference in which TLS library is used has
cropped up between releases? Either way the curl error buffer is empty.
Seems like we aggressively cannot do anything about this.

Change-Id: If0141a46a8b445a0e7d6f86f939e8c8e03569bf5
2024-12-10 12:32:42 -08:00
Tom BereknyeiandJade Lovelace 6334e91b2f feat: better warning for common SSL errors
(cherry picked from commit 3e5bf903413f420c1f997e4b55140761172b8434)
Upstream-PR: https://github.com/NixOS/nix/pull/11246
Change-Id: Iccd92721bbcd92604a4b0e5c845242bdf3dd0f66
2024-11-18 16:49:35 -08:00
eldritch horrors 59e364c2a8 tests: stop using OCR for nix copy tests
this is fragile, slow as fuck, breaks constantly under high concurrency,
and completely unnecessary since ssh bypasses the stdio file descriptors
*anyway*. we do still check that we see ssh messages to ensure that none
of our subprocess handling messes with ssh's /dev/tty, but that's it now

Change-Id: Ib8e31e1999f813d07a27efc63a9d3454a9e4fcdd
2024-10-26 17:50:54 +00:00
Maximilian Bosch 4682e40183 ssh-ng: better way to keep SSH errors visible
A better fix than in 104448e75d, hence a
revert + the fix.

It turns out that this commit has the side-effect that when having e.g.
`StrictHostKeyChecking=accept-new` for a remote builder, the warnings à la

    Warning: Permanently added 'builder' (ED25519) to the list of known hosts.

actually end up in the derivation's log whereas hostkey verification
errors don't, but only in the stderr of the `nix-build` invocation
(which was the motivation for the patch).

This change writes the stderr from the build-hook to

* the daemon's stderr, so that the SSH errors appear in the journal
  (which was the case before 104448e75d)
* the client's stderr, as a log message
* NOT to the drv log (this is handled via `handleJSONLogMessage`)

I tried to fix the issue for legacy-ssh as well, but failed and
ultimately decided to not bother.

I know that we'll sooner or later replace the entire component, however
this is the part of the patch I have working for a while, so I figured I
might still submit it for the time being.

Change-Id: I21ca1aa0d8ae281d2eacddf26e0aa825272707e5
2024-10-14 06:01:18 +00:00
Puck Meerburg 37b22dae04 Fix passing custom CA files into the builtin:fetchurl sandbox
Without this, verifying TLS certificates would fail on macOS, as well
as any system that doesn't have a certificate file at /etc/ssl/certs/ca-certificates.crt,
which includes e.g. Fedora.

Change-Id: Iaa2e0e9db3747645b5482c82e3e0e4e8f229f5f9
2024-09-26 15:25:28 +00:00
Eelco DolstraandJade Lovelace c1631b0a39 [security] builtin:fetchurl: Enable TLS verification
This is better for privacy and to avoid leaking netrc credentials in a
MITM attack, but also the assumption that we check the hash no longer
holds in some cases (in particular for impure derivations).

Partially reverts https://github.com/NixOS/nix/commit/5db358d4d78aea7204a8f22c5bf2a309267ee038.

(cherry picked from commit c04bc17a5a0fdcb725a11ef6541f94730112e7b6)
(cherry picked from commit f2f47fa725fc87bfb536de171a2ea81f2789c9fb)
(cherry picked from commit 7b39cd631e0d3c3d238015c6f450c59bbc9cbc5b)

Upstream-PR: https://github.com/NixOS/nix/pull/11585

Change-Id: Ia973420f6098113da05a594d48394ce1fe41fbb9
2024-09-25 18:40:58 -07:00
piegames 1c080a8239 treewide: Stop using URL literals
They must die

Change-Id: Ibe2b1818b21d98ec1a68836d01d5dad729b8c501
2024-08-17 15:48:10 +00:00
Maximilian BoschandJade Lovelace 87fd1f024c Reapply "libfetchers: make attribute / URL query handling consistent"
The original attempt at this introduced a regression; this commit
reverts the revert and fixes the regression.

This reverts commit 3e151d4d77.

Fix to the regression:

flakeref: fix handling of `?dir=` param for flakes in subdirs

As reported in #419[1], accessing a flake in a subdir of a Git
repository fails with the previous commit[2] applied with the error

    error: unsupported Git input attribute 'dir'

The problem is that the `dir`-param is inserted into the parsed URL if a
flake is fetched from the subdir of a Git repository. However, for the
fetching part this isn't even needed. The fix is to just pass `subdir`
as second argument to `FlakeRef` (which needs a `basedir` that can be
empty) and leave the parsedURL as-is.

Added a regression test to make sure we don't run into this again.

[1] https://git.lix.systems/lix-project/lix/issues/419
[2] e22172aaf6b6a366cecd3c025590e68fa2b91bcc,
    originally 3e151d4d77

Change-Id: I2c72d5a32e406a7ca308e271730bd0af01c5d18b
2024-08-01 15:41:30 -07:00
Alois Wohlschlager e7188e211a libstore/build: block io_uring
Unfortunately, io_uring is totally opaque to seccomp, and while currently there
are no dangerous operations implemented, there is no guarantee that it remains
this way. This means that io_uring should be blocked entirely to ensure that
the sandbox is future-proof. This has not been observed to cause issues in
practice.

Change-Id: I45d3895f95abe1bc103a63969f444c334dbbf50d
2024-07-25 18:24:45 +02:00
Alois Wohlschlager 127ee1a101 libstore/build: use an allowlist approach to syscall filtering
Previously, system call filtering (to prevent builders from storing files with
setuid/setgid permission bits or extended attributes) was performed using a
blocklist. While this looks simple at first, it actually carries significant
security and maintainability risks: after all, the kernel may add new syscalls
to achieve the same functionality one is trying to block, and it can even be
hard to actually add the syscall to the blocklist when building against a C
library that doesn't know about it yet. For a recent demonstration of this
happening in practice to Nix, see the introduction of fchmodat2 [0] [1].

The allowlist approach does not share the same drawback. While it does require
a rather large list of harmless syscalls to be maintained in the codebase,
failing to update this list (and roll out the update to all users) in time has
rather benign effects; at worst, very recent programs that already rely on new
syscalls will fail with an error the same way they would on a slightly older
kernel that doesn't support them yet. Most importantly, no unintended new ways
of performing dangerous operations will be silently allowed.

Another possible drawback is reduced system call performance due to the larger
filter created by the allowlist requiring more computation [2]. However, this
issue has not convincingly been demonstrated yet in practice, for example in
systemd or various browsers. To the contrary, it has been measured that the the
actual filter constructed here has approximately the same overhead as a very
simple filter blocking only one system call.

This commit tries to keep the behavior as close to unchanged as possible. The
system call list is in line with libseccomp 2.5.5 and glibc 2.39, which are the
latest versions at the point of writing. Since libseccomp 2.5.5 is already a
requirement and the distributions shipping this together with older versions of
glibc are mostly not a thing any more, this should not lead to more build
failures any more.

[0] https://github.com/NixOS/nixpkgs/issues/300635
[1] https://github.com/NixOS/nix/issues/10424
[2] https://github.com/flatpak/flatpak/pull/4462#issuecomment-1061690607

Change-Id: I541be3ea9b249bcceddfed6a5a13ac10b11e16ad
2024-07-25 18:24:40 +02:00
Qyriad ae7eab49b9 nix3-upgrade-nix: always use the /new/ nix-env to perform the installation
Fixes #411.

Change-Id: I8d87c0e9295deea26ff33234e15ee33cc68ab303
2024-07-15 15:26:53 -06:00
jadeandGerrit Code Review 3e151d4d77 Revert "libfetchers: make attribute / URL query handling consistent"
This reverts commit 35eec921af.

Reason for revert: Regressed nix-eval-jobs, and it appears to be this change is buggy/missing a case. It just needs another pass.

Code causing the problem in n-e-j, when invoked with `nix-eval-jobs --flake '.#hydraJobs'`:

```
n-e-j/tests/assets » ../../build/src/nix-eval-jobs --meta --workers 1 --flake .#hydraJobs
warning: unknown setting 'trusted-users'
warning: `--gc-roots-dir' not specified
error: unsupported Git input attribute 'dir'
error: worker error: error: unsupported Git input attribute 'dir'
```

```
  nix::Value *vRoot = [&]() {
        if (args.flake) {
            auto [flakeRef, fragment, outputSpec] =
                nix::parseFlakeRefWithFragmentAndExtendedOutputsSpec(
                    args.releaseExpr, nix::absPath("."));
            nix::InstallableFlake flake{
                {}, state, std::move(flakeRef), fragment, outputSpec,
                {}, {},    args.lockFlags};

            return flake.toValue(*state).first;
        } else {
            return releaseExprTopLevelValue(*state, autoArgs, args);
        }
    }();
```

Inspecting the program behaviour reveals that `dir` was in fact set in the URL going into the fetcher. This is in turn because unlike in the case changed in this commit, it was not erased before handing it to libfetchers, which is probably just a mistake.

```
(rr) up
3  0x00007ffff60262ae in nix::fetchers::Input::fromURL (url=..., requireTree=requireTree@entry=true) at src/libfetchers/fetchers.cc:39
warning: Source file is more recent than executable.
39              auto res = inputScheme->inputFromURL(url, requireTree);
(rr) p url
$1 = (const nix::ParsedURL &) @0x7fffdc874190: {url = "git+file:///home/jade/lix/nix-eval-jobs", 
  base = "git+file:///home/jade/lix/nix-eval-jobs", scheme = "git+file", authority = std::optional<std::string> = {[contained value] = ""}, 
  path = "/home/jade/lix/nix-eval-jobs", query = std::map with 1 element = {["dir"] = "tests/assets"}, fragment = ""}
(rr) up
4  0x00007ffff789d904 in nix::parseFlakeRefWithFragment (url=".#hydraJobs", baseDir=std::optional<std::string> = {...}, 
    allowMissing=allowMissing@entry=false, isFlake=isFlake@entry=true) at src/libexpr/flake/flakeref.cc:179
warning: Source file is more recent than executable.
179                                 FlakeRef(Input::fromURL(parsedURL, isFlake), getOr(parsedURL.query, "dir", "")),
(rr) p parsedURL
$2 = {url = "git+file:///home/jade/lix/nix-eval-jobs", base = "git+file:///home/jade/lix/nix-eval-jobs", scheme = "git+file", 
  authority = std::optional<std::string> = {[contained value] = ""}, path = "/home/jade/lix/nix-eval-jobs", query = std::map with 1 element = {
    ["dir"] = "tests/assets"}, fragment = ""}
(rr) list
174
175                             if (pathExists(flakeRoot + "/.git/shallow"))
176                                 parsedURL.query.insert_or_assign("shallow", "1");
177
178                             return std::make_pair(
179                                 FlakeRef(Input::fromURL(parsedURL, isFlake), getOr(parsedURL.query, "dir", "")),
180                                 fragment);
181                         }
```

Change-Id: Ib55a882eaeb3e59228857761dc1e3b2e366b0f5e
2024-06-24 22:49:17 +00:00
Maximilian Bosch 35eec921af libfetchers: make attribute / URL query handling consistent
The original idea was to fix lix#174, but for a user friendly solution,
I figured that we'd need more consistency:

* Invalid query params will cause an error, just like invalid
  attributes. This has the following two consequences:

  * The `?dir=`-param from flakes will be removed before the URL to be
    fetched is passed to libfetchers.

  * The tarball fetcher doesn't allow URLs with custom query params
    anymore. I think this was questionable anyways given that an
    arbitrary set of query params was silently removed from the URL you
    wanted to fetch. The correct way is to use an attribute-set
    with a key `url` that contains the tarball URL to fetch.

  * Same for the git & mercurial fetchers: in that case it doesn't even
    matter though: both fetchers added unused query params to the URL
    that's passed from the input scheme to the fetcher (`url2` in the code).
    It turns out that this was never used since the query parameters were
    erased again in `getActualUrl`.

* Validation happens for both attributes and URLs. Previously, a lot of
  fetchers validated e.g. refs/revs only when specified in a URL and
  the validity of attribute names only in `inputFromAttrs`.

  Now, all the validation is done in `inputFromAttrs` and `inputFromURL`
  constructs attributes that will be passed to `inputFromAttrs`.

* Accept all attributes as URL query parameters. That also includes
  lesser used ones such as `narHash`.

  And "output" attributes like `lastModified`: these could be declared
  already when declaring inputs as attribute rather than URL. Now the
  behavior is at least consistent.

  Personally, I think we should differentiate in the future between
  "fetched input" (basically the attr-set that ends up in the lock-file)
  and "unfetched input" earlier: both inputFrom{Attrs,URL} entrypoints
  are probably OK for unfetched inputs, but for locked/fetched inputs
  a custom entrypoint should be used. Then, the current entrypoints
  wouldn't have to allow these attributes anymore.

Change-Id: I1be1992249f7af8287cfc37891ab505ddaa2e8cd
2024-06-22 14:42:43 +02:00
Pierre BourdonandJade Lovelace f7b6552699 [resubmit] flake: update nixpkgs pin 23.11->24.05 (+ boehmgc compat changes)
-- message from cl/1418 --

The boehmgc changes are bundled into this commit because doing otherwise
would require an annoying dance of "adding compatibility for < 8.2.6 and
>= 8.2.6" then updating the pin then removing the (now unneeded)
compatibility. It doesn't seem worth the trouble to me given the low
complexity of said changes.

Rebased coroutine-sp-fallback.diff patch taken from https://github.com/NixOS/nixpkgs/pull/317227

-- jade resubmit changes --

This is a resubmission of https://gerrit.lix.systems/c/lix/+/1418, which
was reverted in https://gerrit.lix.systems/c/lix/+/1432 for breaking CI
evaluation without being detected.

I have run `nix flake check -Lv` on this one before submission and it
passes on my machine and crucially without eval errors, so the CI result
should be accurate.

It seems like someone renamed forbiddenDependenciesRegex to
forbiddenDependenciesRegexes in nixpkgs and also changed the type
incompatibly. That's pretty silly, but at least it's just an eval error.

Also, `xonsh` regressed the availability of `xonsh-unwrapped`, but it
was fixed by us in https://github.com/NixOS/nixpkgs/pull/317636, which
is now in our channel, so we update nixpkgs compared to the original
iteration of this to simply get that.

We originally had a regression related to some reorganization of the
nixpkgs lib test suite in which there was broken parameter passing.
This, too, we got quickfixed in nixpkgs, so we don't need any changes
for it: https://github.com/NixOS/nixpkgs/pull/317772

Related: https://gerrit.lix.systems/c/lix/+/1428
Fixes: https://git.lix.systems/lix-project/lix/issues/385

Change-Id: I26d41ea826fec900ebcad0f82a727feb6bcd28f3
2024-06-12 15:34:22 -07:00
Pierre Bourdon 9281a12532 tests/nixos/nix-copy: fix NixOS >= 24.05 compatibility
4b128008c5d9fde881ce1b0a25e60ae0415a14d5 in nixpkgs introduced a default
hashedPasswordFile for root in NixOS tests, which takes precedence over
the password option set in the nix-copy test.

Change-Id: Iffaebec5992e50614b854033f0d14312c8d275b5
2024-06-08 17:59:08 +02:00
Pierre Bourdon a3256a9375 tests/nixos: make the tarball-flakes test better reflect real use cases
In most real world cases, the Link header is set on the redirect, not on
the final file. This regressed in Lix earlier and while new unit tests
were added to cover it, this integration test should probably have also
caught it.

Change-Id: I2a9d8d952fff36f2c22cfd751451c2b523f7045c
2024-06-04 08:12:59 +02:00
Alois Wohlschlager f047e4357b libstore/build: always enable seccomp filtering and no-new-privileges
Seccomp filtering and the no-new-privileges functionality improve the security
of the sandbox, and have been enabled by default for a long time. In
https://git.lix.systems/lix-project/lix/issues/265 it was decided that they
should be enabled unconditionally. Accordingly, remove the allow-new-privileges
(which had weird behavior anyway) and filter-syscall settings, and force the
security features on. Syscall filtering can still be enabled at build time to
support building on architectures libseccomp doesn't support.

Change-Id: Iedbfa18d720ae557dee07a24f69b2520f30119cb
2024-05-24 21:19:29 +00:00
Pierre Bourdon 6260563bed nixos/tests: enable remoteBuilds tests against Nix 2.18
Fixes #321.

Change-Id: I60812aec9f9b68ab742413835c581d3b53432b9b
2024-05-23 21:16:40 +02:00
julia 7a3745b076 Deprecate the online flake registries and vendor the default registry
Fixes #183, #110, #116.

The default flake-registry option becomes 'vendored', and refers
to a vendored flake-registry.json file in the install path.

Vendored copy of the flake-registry is from github:NixOS/flake-registry
at commit 9c69f7bd2363e71fe5cd7f608113290c7614dcdd.

Change-Id: I752b81c85ebeaab4e582ac01c239d69d65580f37
2024-05-18 12:27:23 +10:00
midnightveilandJade Lovelace 5b7dcb3005 Allow enabling core dumps from builds for nix & child processes
Fixes https://git.lix.systems/lix-project/lix/issues/268

Change-Id: I3f1b0ddf064f891cca8b53229c5c31c74cea3d9f
2024-05-16 17:11:21 -07:00
Jade Lovelace 9909a175bf Fix /etc/group having desynced IDs from the actual UID in the sandbox
This was found when `logrotate.conf` failed to build in a NixOS system
with:

    /nix/store/26zdl4pyw5qazppj8if5lm8bjzxlc07l-coreutils-9.3/bin/id: cannot find name for group ID 30000

This was surprising because it seemed to mean that /etc/group was busted
in the sandbox. Indeed it was:

    root:x:0:
    nixbld:!💯
    nogroup:x:65534:

We diagnosed this to sandboxUid() being called before
usingUserNamespace() was called, in setting up /etc/group inside the
sandbox. This code desperately needs refactoring.

We also moved the /etc/group code to be with the /etc/passwd code, but
honestly this code is all spaghetti'd all over the place and needs some
more serious tidying than we did here.

We also moved some checks to be earlier to improve locality with where
the things they are checking come from.

Change-Id: Ie29798771f3593c46ec313a32960fa955054aceb
2024-05-04 17:36:50 -07:00
Maximilian BoschandGerrit Code Review 79d0ae6670 Merge "libstore/local-derivation-goal: prohibit creating setuid/setgid binaries" into main 2024-05-04 07:26:15 +00:00
Maximilian Bosch 045ee37438 libstore/local-derivation-goal: prohibit creating setuid/setgid binaries
With Linux kernel >=6.6 & glibc 2.39 a `fchmodat2(2)` is available that
isn't filtered away by the libseccomp sandbox.

Being able to use this to bypass that restriction has surprising results
for some builds such as lxc[1]:

> With kernel ≥6.6 and glibc 2.39, lxc's install phase uses fchmodat2,
> which slips through https://github.com/NixOS/nix/blob/9b88e5284608116b7db0dbd3d5dd7a33b90d52d7/src/libstore/build/local-derivation-goal.cc#L1650-L1663.
> The fixupPhase then uses fchmodat, which fails.
> With older kernel or glibc, setting the suid bit fails in the
> install phase, which is not treated as fatal, and then the
> fixup phase does not try to set it again.

Please note that there are still ways to bypass this sandbox[2] and this is
mostly a fix for the breaking builds.

This change works by creating a syscall filter for the `fchmodat2`
syscall (number 452 on most systems). The problem is that glibc 2.39
is needed to have the correct syscall number available via
`__NR_fchmodat2` / `__SNR_fchmodat2`, but this flake is still on
nixpkgs 23.11. To have this change everywhere and not dependent on the
glibc this package is built against, I added a header
"fchmodat2-compat.hh" that sets the syscall number based on the
architecture. On most platforms its 452 according to glibc with a few
exceptions:

    $ rg --pcre2 'define __NR_fchmodat2 (?!452)'
    sysdeps/unix/sysv/linux/x86_64/x32/arch-syscall.h
    58:#define __NR_fchmodat2 1073742276

    sysdeps/unix/sysv/linux/mips/mips64/n32/arch-syscall.h
    67:#define __NR_fchmodat2 6452

    sysdeps/unix/sysv/linux/mips/mips64/n64/arch-syscall.h
    62:#define __NR_fchmodat2 5452

    sysdeps/unix/sysv/linux/mips/mips32/arch-syscall.h
    70:#define __NR_fchmodat2 4452

    sysdeps/unix/sysv/linux/alpha/arch-syscall.h
    59:#define __NR_fchmodat2 562

I added a small regression-test to the setuid integration-test that
attempts to set the suid bit on a file using the fchmodat2 syscall.
I confirmed that the test fails without the change in
local-derivation-goal.

Additionally, we require libseccomp 2.5.5 or greater now: as it turns
out, libseccomp maintains an internal syscall table and
validates each rule against it. This means that when using libseccomp
2.5.4 or older, one may pass `452` as syscall number against it, but
since it doesn't exist in the internal structure, `libseccomp` will refuse
to create a filter for that. This happens with nixpkgs-23.11, i.e. on
stable NixOS and when building Lix against the project's flake.

To work around that

* a backport of libseccomp 2.5.5 on upstream nixpkgs has been
  scheduled[3].

* the package now uses libseccomp 2.5.5 on its own already. This is to
  provide a quick fix since the correct fix for 23.11 is still a staging cycle
  away.

We still need the compat header though since `SCMP_SYS(fchmodat2)`
internally transforms this into `__SNR_fchmodat2` which points to
`__NR_fchmodat2` from glibc 2.39, so it wouldn't build on glibc 2.38.
The updated syscall table from libseccomp 2.5.5 is NOT used for that
step, but used later, so we need both, our compat header and their
syscall table 🤷

Relevant PRs in CppNix:

* https://github.com/NixOS/nix/pull/10591
* https://github.com/NixOS/nix/pull/10501

[1] https://github.com/NixOS/nixpkgs/issues/300635#issuecomment-2031073804
[2] https://github.com/NixOS/nixpkgs/issues/300635#issuecomment-2030844251
[3] https://github.com/NixOS/nixpkgs/pull/306070

(cherry picked from commit ba6804518772e6afb403dd55478365d4b863c854)
Change-Id: I6921ab5a363188c6bff617750d00bb517276b7fe
2024-05-03 16:29:06 +02:00
Qyriad e2ab89a74b add VM test for nix upgrade-nix
This commit adds a new NixOS VM test, which tests that `nix upgrade-nix`
works on both kinds of profiles (manifest.nix and manifest.json).

Done as a separate commit from 831d18a13, since it relies on the
--store-path argument from 026c90e5f as well.

Change-Id: I5fc94b751d252862cb6cffb541a4c072faad9f3b
2024-04-29 01:19:21 +00:00
Maximilian BoschandGerrit Code Review 8773439a85 Merge "ssh-ng: Set log-fd for ssh to 4 by default" into main 2024-04-26 18:30:33 +00:00