This works because the `builder` and `args` variables are only used
in the non-builtin code path.
Co-Authored-By: Théophane Hufschmitt <theophane.hufschmitt@tweag.io>
https://github.com/NixOS/nix/pull/10456 fixed the addition of symlink
store paths to the sandbox, but also made it so that the hardcoded
sandbox paths (like `/etc/hosts`) were now bind-mounted without
following the possible symlinks. This made these files unreadable if
there were symlinks (because the sandbox would now contain a symlink to
an unreachable file rather than the underlying file).
In particular, this broke FOD derivations on NixOS as `/etc/hosts` is a
symlink there.
Fix that by canonicalizing all these hardcoded sandbox paths before
adding them to the sandbox.
(cherry picked from commit acbb1523c1)
This patch has been manually adapted from
14dc84ed03
Tested with:
$ NIX_SSL_CERT_FILE=$(nix-build '<nixpkgs>' -A cacert)/etc/ssl/certs/ca-bundle.crt nix-build --store $(mktemp -d) -E 'import <nix/fetchurl.nix> { url = https://google.com; }'
warning: found empty hash, assuming 'sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA='
this derivation will be built:
/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv
building '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv'...
error:
… writing file '/nix/store/0zynn4n8yx59bczy1mgh1lq2rnprvvrc-google.com'
error: unable to download 'https://google.com': Problem with the SSL CA cert (path? access rights?) (77)
error: builder for '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv' failed with exit code 1
Now returns:
nix-env % NIX_SSL_CERT_FILE=$(nix-build '<nixpkgs>' -A cacert)/etc/ssl/certs/ca-bundle.crt nix-build --store $(mktemp -d) -E 'import <nix/fetchurl.nix> { url = https://google.com; }'
this derivation will be built:
/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv
building '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv'...
error: hash mismatch in fixed-output derivation '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv':
specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
got: sha256-5xXEhGtnRdopaUTqaz2M1o2NE7ovhU0SjcSOPwntqwY=
(cherry picked from commit 1fbdf409524bb350b8614f3d95067cb9ba3c57f2)
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 5db358d4d7.
(cherry picked from commit c04bc17a5a)
Caused by 1d3696f0fb
Without this fix the kept build directory is readable only by root
```
$ sudo ls -ld /comp-temp/nix-build-openssh-static-x86_64-unknown-linux-musl-9.8p1.drv-5
drwx------ root root 60 B Wed Sep 11 00:09:48 2024 /comp-temp/nix-build-openssh-static-x86_64-unknown-linux-musl-9.8p1.drv-5/
$ sudo ls -ld /comp-temp/nix-build-openssh-static-x86_64-unknown-linux-musl-9.8p1.drv-5/build
drwxr-xr-x nixbld1 nixbld 80 B Wed Sep 11 00:09:58 2024 /comp-temp/nix-build-openssh-static-x86_64-unknown-linux-musl-9.8p1.drv-5/build/
```
(cherry picked from commit ebebe626ff)
Starting in macOS 15 Sequoia, macOS daemon UIDs are encroaching on our
default UIDs of 301-332. This commit relocates our range up to avoid
clashing with the current UIDs of 301-304 and buy us a little time
while still leaving headroom for people installing more than 32 users.
(cherry picked from commit df36ff0d1e)
The recent fix for CVE-2024-38531 broke the sandbox on macOS
completely. As it’s not practical to use `chroot(2)` on
macOS, the build takes place in the main filesystem tree, and the
world‐unreadable wrapper directory prevents the build from accessing
its `$TMPDIR` at all.
The macOS sandbox probably shouldn’t be treated as any kind of a
security boundary in its current state, but this specific vulnerability
wasn’t possible to exploit on macOS anyway, as creating `set{u,g}id`
binaries is blocked by sandbox policy.
Locking down the build sandbox further may be a good idea in future,
but it already has significant compatibility issues. For now, restore
the previous status quo on macOS.
Thanks to @alois31 for helping me come to a better understanding of
the vulnerability.
Fixes: 1d3696f0fbCloses: #11002
(cherry picked from commit af2e1142b1)
(cherry picked from commit 9feee13952)
After the fix for CVE-2024-38531, this was only removing the nested
build directory, rather than the top‐level temporary directory.
Fixes: 1d3696f0fb
(cherry picked from commit 76e4adfaac)
(cherry picked from commit 0d68b40dda)
When sandboxing is disabled, we cannot put $TMPDIR underneath an
inaccessible directory.
(cherry picked from commit 86ca2d6d94c0581fda0c666c5e022784952f3542)
(cherry picked from commit 8f58b98770)
Previously, the .chroot directory had permission 750 or 755 (depending
on the uid-range system feature) and was owned by root/nixbld. This
makes it possible for any nixbld user (if uid-range is disabled) or
any user (if uid-range is enabled) to inspect the contents of the
chroot of an active build and maybe interfere with it (e.g. via /tmp
in the chroot, which has 1777 permission).
To prevent this, the root is now a subdirectory of .chroot, which has
permission 700 and is owned by root/root.
(cherry picked from commit af280e72fa0e62e1c2eaccfb992c0dbb6f27f895)
With Nix 2.3, it was possible to pass a subpath of a store path to
exportReferencesGraph:
with import <nixpkgs> {};
let
hello = writeShellScriptBin "hello" ''
echo ${toString builtins.currentTime}
'';
in
writeClosure [ "${hello}/bin/hello" ]
This regressed with Nix 2.4, with a very confusing error message, that
presumably indicates it was unintentional:
error: path '/nix/store/3gl7kgjr4pwf03f0x70dgx9ln3bhl7zc-hello/bin/hello' is not in the Nix store
(cherry picked from commit 0774e8ba33)
