Commit graph

96 commits

Author SHA1 Message Date
jade 3daeeaefb1 build: implement clang-tidy using our plugin
The principle of this is that you can either externally build it with
Nix (actual implementation will be in a future commit), or it can be
built with meson if the Nix one is not passed in.

The idea I have is that dev shells don't receive the one from Nix to
avoid having to build it, but CI can use the one from Nix and save some
gratuitous rebuilds.

The design of this is that you can run `ninja -C build clang-tidy` and
it will simply correctly clang-tidy the codebase in spite of PCH
bullshit caused by the cc-wrapper.

This is a truly horrendous number of hacks in a ball, caused by bugs in
several pieces of software, and I am not even getting started.

I don't consider this to fix the clang-tidy issue filing, since we still
have a fair number of issues to fix even on the existing minimal
configuration, and I have not yet implemented it in CI. Realistically we
will need to do something like https://github.com/Ericsson/codechecker
to be able to silence warnings without physically touching the code, or
at least *diff* reports between versions.

Also, the run-clang-tidy output design is rather atrocious and must
not be inflicted upon anyone I have respect for, since it buries the
diagnostics in a pile of invocation logs. We would do really well to
integrate with the Gerrit SARIF stuff so we can dump the reports on
people in a user-friendly manner.

Related: #147

Change-Id: Ifefe533f3b56874795de231667046b2da6ff2461
2024-08-04 20:41:19 -07:00
Isabel 9eb374dc6d Merge "nix flake show: add the description if it exists" into main 2024-08-02 07:56:06 +00:00
Max “Goldstein” Siling 1a6d7a3af4 src/libcmd/repl.cc: avoid unneeded reload after :e
If `:edit`ing a store path, don't reload repl afterwards
to avoid losing local variables: store is immutable,
so "editing" a store path is always just viewing it.

Resolves: #341
Change-Id: I3747f75ce26e0595e953069c39ddc3ee80699718
2024-07-30 16:08:26 +00:00
alois31 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
Isabel d2422771eb
nix flake show: add the description if it exists
(cherry picked from commit 8cd1d02f90eb9915e640c5d370d919fad9833c65)

nix flake show: Only print up to the first new line if it exists.

(cherry picked from commit 5281a44927bdb51bfe6e5de12262d815c98f6fe7)

add tests

(cherry picked from commit 74ae0fbdc70a5079a527fe143c4832d1357011f7)

Handle long strings, embedded new lines and empty descriptions

(cherry picked from commit 2ca7b3afdbbd983173a17fa0a822cf7623601367)

Account for total length of 80

(cherry picked from commit 1cc808c18cbaaf26aaae42bb1d7f7223f25dd364)

docs: add nix flake show description release note

fix: remove white space

nix flake show: trim length based on terminal size

test: account for terminal size

docs(flake-description): before and after commands; add myself to credits

Upstream-PR: https://github.com/NixOS/nix/pull/10980
Change-Id: Ie1c667dc816b3dd81e65a1f5395e57ea48ee0362
2024-07-23 13:21:15 +01:00
jade 22252825c4 Merge changes Id8b3d289,Ib75ab5b8,I3792eeb3 into main
* changes:
  Fixup a bunch of references to nixos.org manuals
  Add release notes for removing overflow from Nix language
  expr: fix a compiler warning about different signs in comparison
2024-07-19 18:52:46 +00:00
jade 10cc3b288d Add release notes for removing overflow from Nix language
Change-Id: Ib75ab5b8b4d879035d7ee7678f9cd0c491a39c0a
2024-07-18 19:27:33 +00:00
alois31 768d1f29a2
doc/release-notes: add for pretty printing improvements
Change-Id: I829581a3f5b8b742e6c866dcdbbc635f91afceb5
2024-07-18 19:08:20 +02:00
Quantum Jump 6e0ca02425 Fix dry-run flag for nix-collect-garbage
`nix-collect-garbage --dry-run` previously elided the entire garbage
collection check, meaning that it would just exit the script without
printing anything.

This change makes the dry run flag instead set the GC action to
`gcReturnDead` rather than `gcDeleteDead`, and then continue with the
script. So if you set `--dry-run`, it will print the paths it *would*
have garbage collected, but not actually delete them.

I filed a bug for this: #432 but then realised I could give fixing it a go myself.

Change-Id: I062dbf1a80bbab192b5fd0b3a453a0b555ad16f2
2024-07-09 13:55:05 +00:00
Qyriad 4c7165be86 distinguish between throws & errors during throw
Turns errors like this:

let
  throwMsg = a: throw (a + " invalid bar");
in throwMsg "bullshit"

error:
       … from call site
         at «string»:3:4:
            2|   throwMsg = a: throw (a + " invalid bar");
            3| in throwMsg "bullshit"
             |    ^

       … while calling 'throwMsg'
         at «string»:2:14:
            1| let
            2|   throwMsg = a: throw (a + " invalid bar");
             |              ^
            3| in throwMsg "bullshit"

       … while calling the 'throw' builtin
         at «string»:2:17:
            1| let
            2|   throwMsg = a: throw (a + " invalid bar");
             |                 ^
            3| in throwMsg "bullshit"

       error: bullshit invalid bar

into errors like this:

let
  throwMsg = a: throw (a + " invalid bar");
in throwMsg "bullshit"

error:
       … from call site
         at «string»:3:4:
            2|   throwMsg = a: throw (a + " invalid bar");
            3| in throwMsg "bullshit"
             |    ^

       … while calling 'throwMsg'
         at «string»:2:14:
            1| let
            2|   throwMsg = a: throw (a + " invalid bar");
             |              ^
            3| in throwMsg "bullshit"

       … caused by explicit throw
         at «string»:2:17:
            1| let
            2|   throwMsg = a: throw (a + " invalid bar");
             |                 ^
            3| in throwMsg "bullshit"

       error: bullshit invalid bar

Change-Id: I593688928ece20f97999d1bf03b2b46d9ac338cb
2024-07-04 17:43:03 -06:00
Qyriad 14bf54bd39 trace which part of foo.bar.baz errors
Turns errors like:

let
  somepkg.src = throw "invalid foobar";
in somepkg.src.meta

error:
       … while evaluating the attribute 'src.meta'
         at «string»:2:3:
            1| let
            2|   somepkg.src = throw "invalid foobar";
             |   ^
            3| in somepkg.src.meta

       … while calling the 'throw' builtin
         at «string»:2:17:
            1| let
            2|   somepkg.src = throw "invalid foobar";
             |                 ^
            3| in somepkg.src.meta

       error: invalid foobar

into errors like:

let
  somepkg.src = throw "invalid foobar";
in somepkg.src.meta

error:
       … while evaluating the attribute 'src.meta'
         at «string»:2:3:
            1| let
            2|   somepkg.src = throw "invalid foobar";
             |   ^
            3| in somepkg.src.meta

       … while evaluating 'somepkg.src' to select 'meta' on it
         at «string»:3:4:
            2|   somepkg.src = throw "invalid foobar";
            3| in somepkg.src.meta
             |    ^

       … while calling the 'throw' builtin
         at «string»:2:17:
            1| let
            2|   somepkg.src = throw "invalid foobar";
             |                 ^
            3| in somepkg.src.meta

       error: invalid foobar

And for type errors, from:

let
  somepkg.src = "I'm not an attrset";
in somepkg.src.meta

error:
       … while evaluating the attribute 'src.meta'
         at «string»:2:3:
            1| let
            2|   somepkg.src = "I'm not an attrset";
             |   ^
            3| in somepkg.src.meta

       … while selecting an attribute
         at «string»:3:4:
            2|   somepkg.src = "I'm not an attrset";
            3| in somepkg.src.meta
             |    ^

       error: expected a set but found a string: "I'm not an attrset"

into:

let
  somepkg.src = "I'm not an attrset";
in somepkg.src.meta

error:
       … while evaluating the attribute 'src.meta'
         at «string»:2:3:
            1| let
            2|   somepkg.src = "I'm not an attrset";
             |   ^
            3| in somepkg.src.meta

       … while selecting 'meta' on 'somepkg.src'
         at «string»:3:4:
            2|   somepkg.src = "I'm not an attrset";
            3| in somepkg.src.meta
             |    ^

       error: expected a set but found a string: "I'm not an attrset"

For the low price of an enumerate() and a lambda you too can have the
incorrect line of code actually show up in the trace!

Change-Id: Ic1491c86e33c167891bdac9adad6224784760bd6
2024-07-04 17:42:35 -06:00
Qyriad d00edfb28d trace when the foo part of foo.bar.baz errors
Turns errors like:

let
  errpkg = throw "invalid foobar";
in errpkg.meta

error:
       … while calling the 'throw' builtin
         at «string»:2:12:
            1| let
            2|   errpkg = throw "invalid foobar";
             |            ^
            3| in errpkg.meta

       error: invalid foobar

into errors like:

let
  errpkg = throw "invalid foobar";
in errpkg.meta

error:
       … while evaluating 'errpkg' to select 'meta' on it
         at «string»:3:4:
            2|   errpkg = throw "invalid foobar";
            3| in errpkg.meta
             |    ^

       … while calling the 'throw' builtin
         at «string»:2:12:
            1| let
            2|   errpkg = throw "invalid foobar";
             |            ^
            3| in errpkg.meta

       error: invalid foobar

For the low price of one try/catch, you too can have the incorrect line
of code actually show up in the trace!

Change-Id: If8d6200ec1567706669d405c34adcd7e2d2cd29d
2024-07-04 16:33:02 -06:00
Delan Azabani 865a3732fa Merge "Reject fully-qualified URLs in 'from' argument of nix registry add" into main 2024-07-02 07:20:01 +00:00
jade d3286d0990 Merge changes Ie29a8a89,I873eedcf into main
* changes:
  store: delete obsolete lsof-disabling code
  store: guess the URL of failing fixed-output derivations
2024-07-01 16:11:32 +00:00
alois31 a55112898e
libexpr/flake: allow automatic rejection of configuration options from flakes
The `allow-flake-configuration` option allows the user to control whether to
accept configuration options supplied by flakes. Unfortunately, setting this
to false really meant "ask each time" (with an option to remember the choice
for each specific option encountered). Let no mean no, and introduce (and
default to) a separate value for the "ask each time" behaviour.

Co-Authored-By: Jade Lovelace <lix@jade.fyi>
Change-Id: I7ccd67a95bfc92cffc1ebdc972d243f5191cc1b4
2024-06-30 19:28:14 +02:00
Delan Azabani b2944d93a6 Reject fully-qualified URLs in 'from' argument of nix registry add
We previously allowed you to map any flake URL to any other flake URL,
including shorthand flakerefs, indirect flake URLs like `flake:nixpkgs`,
direct flake URLs like `github:NixOS/nixpkgs`, or local paths.

But flake registry entries mapping from direct flake URLs often come
from swapping the 'from' and 'to' arguments by accident, and even when
created intentionally, they may not actually work correctly.

This patch rejects those URLs (and fully-qualified flake: URLs), making
it harder to swap the arguments by accident.

Fixes #181.

Change-Id: I24713643a534166c052719b8770a4edfcfdb8cf3
2024-06-29 05:11:31 +00:00
jade d92712673b store: guess the URL of failing fixed-output derivations
This is a shameless layering violation in favour of UX. It falls back
trivially to "unknown", so it's purely a UX feature.

Diagnostic sample:

```
error: hash mismatch in fixed-output derivation '/nix/store/sjfw324j4533lwnpmr5z4icpb85r63ai-x1.drv':
        likely URL: https://meow.puppy.forge/puppy.tar.gz
         specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
            got:    sha256-a1Qvp3FOOkWpL9kFHgugU1ok5UtRPSu+NwCZKbbaEro=
```

Change-Id: I873eedcf7984ab23f57a6754be00232b5cb5b02c
2024-06-27 22:44:16 -07:00
jade e19f27917c Add some release notes for things we did
Change-Id: If0ddec6b64a43c3d8f6cae39e0292863f3b49401
2024-06-24 16:26:12 -07:00
Robert Hensing d86009bd76 Add build-dir setting, clean up default TMPDIR handling
This is a squash of upstream PRs #10303, #10312 and #10883.

fix: Treat empty TMPDIR as unset

Fixes an instance of

    nix: src/libutil/util.cc:139: nix::Path nix::canonPath(PathView, bool): Assertion `path != ""' failed.

... which I've been getting in one of my shells for some reason.
I have yet to find out why TMPDIR was empty, but it's no reason for
Nix to break.

(cherry picked from commit c3fb2aa1f9d1fa756dac38d3588c836c5a5395dc)

fix: Treat empty XDG_RUNTIME_DIR as unset

See preceding commit. Not observed in the wild, but is sensible
and consistent with TMPDIR behavior.

(cherry picked from commit b9e7f5aa2df3f0e223f5c44b8089cbf9b81be691)

local-derivation-goal.cc: Reuse defaultTempDir()

(cherry picked from commit fd31945742710984de22805ee8d97fbd83c3f8eb)

fix: remove usage of XDG_RUNTIME_DIR for TMP

(cherry picked from commit 1363f51bcb24ab9948b7b5093490a009947f7453)

tests/functional: Add count()

(cherry picked from commit 6221770c9de4d28137206bdcd1a67eea12e1e499)

Remove uncalled for message

(cherry picked from commit b1fe388d33530f0157dcf9f461348b61eda13228)

Add build-dir setting

(cherry picked from commit 8b16cced18925aa612049d08d5e78eccbf0530e4)
Change-Id: Ic7b75ff0b6a3b19e50a4ac8ff2d70f15c683c16a
2024-06-24 11:30:32 +03:00
kloenk da4e46dd1f libmain: add progress bar with multiple status lines
Add the log-formats `multiline` and `multiline-with-logs` which offer
multiple current active building status lines.

Change-Id: Idd8afe62f8591b5d8b70e258c5cefa09be4cab03
2024-06-22 14:20:27 +02:00
Qyriad 010d93393e repl: implement tab completing :colon commands
This uses a minor hack in which we check the rl_line_buffer global
variable to workaround editline not including the colon in its
completion callback.

Fixes #361

Change-Id: Id159d209c537443ef5e37a975982e8e12ce1f486
2024-06-17 13:08:02 +00:00
jade f95a47e8c4 release: release notes for 2.90.0
For now we just need to put the release notes in the final spot. We will
have to fix the date on both 2.90 and 2.91 branches, but such as it is.

Release created with releng/create_release.xsh

Closes: #318
Change-Id: I38e79b40e7f632c8a286f2f09865a84dc93eca90
2024-06-15 18:46:18 -07:00
jade 611b1de441 Add meson release note
Change-Id: I4d2d08dc77a3ab4dce9fbb129c1487aa8c9f1722
2024-06-06 15:08:12 -07:00
jade 24057dcb6a Remove rl-next-dev
We realized that there's really no good place to put these dev facing
bulletins, and the user-facing release notes aren't really the worst
place to put them, I guess, and we do kind of hope that it converts
users to devs.

Change-Id: Id9387b2964fe291cb5a3f74ad6344157f19b540c
2024-06-06 15:08:12 -07:00
Maximilian Bosch 3d78b4847e Merge "release-notes: add missing credits/category to consistent-nix-build entry" into main 2024-05-30 14:38:47 +00:00
Maximilian Bosch 6abac7aacc release-notes: add missing credits/category to consistent-nix-build entry
Change-Id: I737422a2ff9d66be30cc432f8c1ddba9b1e71f4f
2024-05-30 14:05:12 +00:00
Cole Helbling 031d924116 libutil/args: warn on unknown settings after parsing all flags
Upstream change: https://github.com/NixOS/nix/pull/10701

Change-Id: Icf271df57ec529dd8c64667d1ef9f6dbf02d33d3
2024-05-30 03:07:21 +00:00
alois31 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
#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
jade 19ea351642 Merge "clang-tidy: work with angle brackets and external projects" into main 2024-05-24 19:11:26 +00:00
Qyriad 65da3e7199 make CTRL+Z work in the REPL
Editline just wasn't being built with --enable-sigstop lol

Change-Id: I35a78f74ea100d97f26b2b41990deb373fd9cd9a
2024-05-24 03:10:12 +00:00
jade 745b5d3d4f clang-tidy: work with angle brackets and external projects
Also fix the readme

Change-Id: I422dff5536bf01d43983621aa01035bd77ac0252
2024-05-24 02:22:58 +00:00
jade 9530b7f2b2 Merge "packaging: rename nixexpr -> lixexpr and so on" into main 2024-05-23 23:19:28 +00:00
jade c97e17144e packaging: rename nixexpr -> lixexpr and so on
This breaks downstreams linking to us on purpose to make sure that if
someone is linking to Lix they're doing it on purpose and crucially not
mixing up Nix and Lix versions in compatibility code.

We still need to fix the internal includes to follow the same schema so
we can drop the single-level include system entirely. However, this
requires a little more effort.

This adds pkg-config for libfetchers and config.h.

Migration path:
expr.hh      -> lix/libexpr/expr.hh
nix/config.h -> lix/config.h

To apply this migration automatically, remove all `<nix/>` from
includes, so: `#include <nix/expr.hh>` -> `#include <expr.hh>`. Then,
the correct paths will be resolved from the tangled mess, and the
clang-tidy automated fix will work.

Then run the following for out of tree projects:

```
lix_root=$HOME/lix
(cd $lix_root/clang-tidy && nix develop -c 'meson setup build && ninja -C build')
run-clang-tidy -checks='-*,lix-fixincludes' -load=$lix_root/clang-tidy/build/liblix-clang-tidy.so -p build/ -fix src
```

Related: lix-project/nix-eval-jobs#5
Fixes: #279
Change-Id: I7498e903afa6850a731ef8ce77a70da6b2b46966
2024-05-23 16:45:23 -06:00
jade dcc7ea5498 release notes: add a bunch of them
Also fix typos introduced by the commits I read.

I have run the addDrvOutputDependencies release note past Ericson since
I was confused by what the heck it was doing, and he was saying it was
reasonable.

Change-Id: Id015353b00938682f7faae7de43df7f991a5237e
2024-05-22 21:13:56 +02:00
alois31 0bf4c2971f Merge "doc: fix repl-interrupt release note entry" into main 2024-05-22 18:59:54 +00:00
alois31 d5fdb995d3
doc: fix repl-interrupt release note entry
The timing of the merge resulted in the newly introduced metadata not being
present.

Change-Id: I07f28cf37703ec05c3e1b96301797a42d913264b
2024-05-21 16:34:04 +02:00
Qyriad 20981461d4 print type and value in "flake attr is not a derivation" errors
This turns errors like:

error: flake output attribute 'hydraJobs' is not a derivation or path

into errors like:

error: expected flake output attribute 'hydraJobs' to be a derivation or
path but found a set: { binaryTarball = «thunk»; build = «thunk»; etc> }

This change affects all InstallableFlake commands.

Change-Id: I899757af418b6f98201006ec6ee13a448c07077c
2024-05-21 05:55:13 -06:00
puck bfb91db4f6 repl-interacter: save history after entering every line
Fixes: #328
Change-Id: Iedd79ff5f72e84766ebd234c63856170afc624f0
2024-05-19 22:47:45 +00:00
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
julia 5b7dcb3005 Allow enabling core dumps from builds for nix & child processes
Fixes #268

Change-Id: I3f1b0ddf064f891cca8b53229c5c31c74cea3d9f
2024-05-16 17:11:21 -07:00
jade 6d84d6bdc1 builtins: fix builtins.langVersion docs to state it's deprecated
This builtin was always a problem and nixpkgs uses it in exactly one
place, to give up if the Nix version is absurdly old. It has no other
use cases, and doesn't work in a multi-implementation world anyway.

Change-Id: I03c36e118591029e2ef14b091fe14a311c66a08a
2024-05-15 21:54:12 -07:00
jade 272db8af1b doc: add release note credits and categories for all the changes in Lix
This does not add missing release notes, and it doesn't do anything
about the profiles feature we would really like to have so we can have
consistent credit.

Change-Id: I72a6f7acfcff85f380be17dac76501a6f4693776
2024-05-15 14:33:35 -07:00
Maximilian Bosch aabc902040 Merge "nix3-build: show all FOD errors with --keep-going" into main 2024-05-15 18:46:06 +00:00
Maximilian Bosch e146393183
nix3-build: show all FOD errors with --keep-going
Basically I'd expect the same behavior as with `nix-build`, i.e.
with `--keep-going` the hash-mismatch error of each failing
fixed-output derivation is shown.

The approach is derived from `Store::buildPaths` (`entry-point.cc`):
instead of throwing the first build-result, check if there are any build
errors and if so, display all of them and throw after that.

Unfortunately, the BuildResult struct doesn't have an `ErrorInfo`
(there's a FIXME for that at least), so I have to construct my own here.
This is a rather cheap bugfix and I decided against touching too many
parts of libstore for that (also I don't know if that's in line with the
ongoing refactoring work).

Closes #302

Change-Id: I378ab984fa271e6808c6897c45e0f070eb4c6fac
2024-05-15 15:35:18 +02:00
alois31 914b0febf7
libutil: remove the interrupt-blocking code
The interrupt-blocking code was originally introduced 20 years ago so that
trying to log an error message does not result in an interrupt exception being
thrown and then going unhandled (c8d3882cdc).
However, the logging code does not check for interrupts any more
(054be50257), so this reasoning is no longer
applicable. Delete this code so that later interrupts are unblocked again, for
example in the next line entered into the repl.

Closes: #296
Change-Id: I48253f5f4272e75001148c13046e709ef5427fbd
2024-05-13 09:03:53 +02:00
jade 748d8310fa Fix the pages in the manual for Lix
This doesn't comprehensively fix everything outdated in the manual, or
make the manual greatly better, but it does note down where at least
jade noticed it was wrong, and it does fix all the instances of
referencing Nix to conform to the style guide to the best of our
ability.

A lot of things have been commented out for being wrong, and there are
three types of FIXME introduced:

- FIXME(Lix): generically Lix needs to fix it
- FIXME(Qyriad): re #215
- FIXME(meson): docs got outdated by meson changes and need rewriting

I did fix a bunch of it that I could, but there could certainly be
mistakes and this is definitely just an incremental improvement.

Fixes: #266
Change-Id: I5993c4603d7f026a887089fce77db08394362135
2024-05-05 16:11:01 -07:00
Maximilian Bosch 799d0132f0 Merge "Revert "Revert "Merge pull request #6621 from Kha/nested-follows""" into main 2024-05-04 08:52:29 +00:00
Maximilian Bosch 79d0ae6670 Merge "libstore/local-derivation-goal: prohibit creating setuid/setgid binaries" into main 2024-05-04 07:26:15 +00:00
Maximilian Bosch 0e38720502 Revert "Revert "Merge pull request #6621 from Kha/nested-follows""
This reverts commit a8b3d777fb.

This undoes the revert of PR#6621, which allows nested `follows`, i.e.

    {
      inputs = {
        foo.url = "github:bar/foo";
        foo.inputs.bar.inputs.nixpkgs = "nixpkgs";
      };
    }

does the expected thing now. This is useful to avoid the 1000 instances
of nixpkgs problem without having each flake in the dependency tree to
expose all of its transitive dependencies for modification.

This was in fact part of Nix before and the C++ changes applied w/o
conflicts. However, it got reverted then because people didn't want to
merge lazy-trees against it which was supposed to be merged soon back in
October 2022.

Fixes: #201

Change-Id: I5ddef914135b695717b2ef88862d57ced5e7aa3c
2024-05-03 22:54:38 +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 9b88e52846/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