Squashed commit of the following:
commit 04fff3a637d455cbb1d75937a235950e43008db9
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 12:30:32 2025 +0200
Chown structured attr files safely
commit 5417ad445e414c649d0cfc71a05661c7bf8f3ef5
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 12:14:04 2025 +0200
Replace 'bool sync' with an enum for clarity
And drop writeFileAndSync().
commit 7ae0141f328d8e8e1094be24665789c05f974ba6
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 11:35:28 2025 +0200
Drop guessOrInventPathFromFD()
No need to do hacky stuff like that when we already know the original path.
commit 45b05098bd019da7c57cd4227a89bfd0fa65bb08
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 11:15:58 2025 +0200
Tweak comment
commit 0af15b31209d1b7ec8addfae9a1a6b60d8f35848
Author: Raito Bezarius <raito@lix.systems>
Date: Thu Mar 27 12:22:26 2025 +0100
libstore: ensure that temporary directory is always 0o000 before deletion
In the case the deletion fails, we should ensure that the temporary
directory cannot be used for nefarious purposes.
Change-Id: I498a2dd0999a74195d13642f44a5de1e69d46120
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 2c20fa37b15cfa03ac6a1a6a47cdb2ed66c0827e
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 12:42:55 2025 +0100
libutil: ensure that `_deletePath` does NOT use absolute paths with dirfds
When calling `_deletePath` with a parent file descriptor, `openat` is
made effective by using relative paths to the directory file descriptor.
To avoid the problem, the signature is changed to resist misuse with an
assert in the prologue of the function.
Change-Id: I6b3fc766bad2afe54dc27d47d1df3873e188de96
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit d3c370bbcae48bb825ce19fd0f73bb4eefd2c9ea
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:07:47 2025 +0100
libstore: ensure that `passAsFile` is created in the original temp dir
This ensures that `passAsFile` data is created inside the expected
temporary build directory by `openat()` from the parent directory file
descriptor.
This avoids a TOCTOU which is part of the attack chain of CVE-????.
Change-Id: Ie5273446c4a19403088d0389ae8e3f473af8879a
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 45d3598724f932d024ef6bc2ffb00c1bb90e6018
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:06:03 2025 +0100
libutil: writeFile variant for file descriptors
`writeFile` lose its `sync` boolean flag to make things simpler.
A new `writeFileAndSync` function is created and all call sites are
converted to it.
Change-Id: Ib871a5283a9c047db1e4fe48a241506e4aab9192
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 732bd9b98cabf4aaf95a01fd318923de303f9996
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:05:34 2025 +0100
libstore: chown to builder variant for file descriptors
We use it immediately for the build temporary directory.
Change-Id: I180193c63a2b98721f5fb8e542c4e39c099bb947
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 962c65f8dcd5570dd92c72370a862c7b38942e0d
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:04:59 2025 +0100
libstore: open build directory as a dirfd as well
We now keep around a proper AutoCloseFD around the temporary directory
which we plan to use for openat operations and avoiding the build
directory being swapped out while we are doing something else.
Change-Id: I18d387b0f123ebf2d20c6405cd47ebadc5505f2a
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit c9b42462b75b5a37ee6564c2b53cff186c8323da
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:04:12 2025 +0100
libutil: guess or invent a path from file descriptors
This is useful for certain error recovery paths (no pun intended) that
does not thread through the original path name.
Change-Id: I2d800740cb4f9912e64c923120d3f977c58ccb7e
Signed-off-by: Raito Bezarius <raito@lix.systems>
Fixes
error:
… while processing sandbox path '/private/tmp/nix-shell.0MDgyx/nix-test/ca/repl/store/nix/var/nix/builds/nix-build-simple.drv-65916-3910734210' (/private/tmp/nix-shell.0MDgyx/nix-test/ca/repl/store)
error: 'nix' is too short to be a valid store path
which happened because we were now putting the build directory
underneath the store directory.
If a build directory is accessible to other users it is possible to
smuggle data in and out of build directories. Usually this is only
a build purity problem, but in combination with other issues it can
be used to break out of a build sandbox. to prevent this we default
to using a subdirectory of nixStateDir (which is more restrictive).
(cherry picked from pennae Lix commit 55b416f6897fb0d8a9315a530a9b7f0914458ded)
(store setting done by roberth)
In the case the deletion fails, we should ensure that the temporary
directory cannot be used for nefarious purposes.
Change-Id: I498a2dd0999a74195d13642f44a5de1e69d46120
Signed-off-by: Raito Bezarius <raito@lix.systems>
When calling `_deletePath` with a parent file descriptor, `openat` is
made effective by using relative paths to the directory file descriptor.
To avoid the problem, the signature is changed to resist misuse with an
assert in the prologue of the function.
Change-Id: I6b3fc766bad2afe54dc27d47d1df3873e188de96
Signed-off-by: Raito Bezarius <raito@lix.systems>
This ensures that `passAsFile` data is created inside the expected
temporary build directory by `openat()` from the parent directory file
descriptor.
This avoids a TOCTOU which is part of the attack chain of CVE-????.
Change-Id: Ie5273446c4a19403088d0389ae8e3f473af8879a
Signed-off-by: Raito Bezarius <raito@lix.systems>
`writeFile` lose its `sync` boolean flag to make things simpler.
A new `writeFileAndSync` function is created and all call sites are
converted to it.
Change-Id: Ib871a5283a9c047db1e4fe48a241506e4aab9192
Signed-off-by: Raito Bezarius <raito@lix.systems>
We use it immediately for the build temporary directory.
Change-Id: I180193c63a2b98721f5fb8e542c4e39c099bb947
Signed-off-by: Raito Bezarius <raito@lix.systems>
We now keep around a proper AutoCloseFD around the temporary directory
which we plan to use for openat operations and avoiding the build
directory being swapped out while we are doing something else.
Change-Id: I18d387b0f123ebf2d20c6405cd47ebadc5505f2a
Signed-off-by: Raito Bezarius <raito@lix.systems>
This is useful for certain error recovery paths (no pun intended) that
does not thread through the original path name.
Change-Id: I2d800740cb4f9912e64c923120d3f977c58ccb7e
Signed-off-by: Raito Bezarius <raito@lix.systems>
Running parallel nix in nix can lead to multiple instances trying to
create the state directories and failing on the `createSymlink` step,
because the link already exists.
`replaceSymlink` is already idempotent, so let's use that.
Resolves#2706
We can always compute the store path from the content hash, but not
vice versa. Storing the content hash allows `hashPath()` to be
replaced by `fetchToStore(...FetchMode::DryRun...)`, which gets us
caching in lazy-trees mode.
This prevents C++ level undefined behavior from affecting
the evaluator. Stdlib implementation details should not affect
eval, regardless of the build platform. Even erroneous usage
of `builtins.sort` should not make it possible to crash the
evaluator or produce results that depend on the host platform.
Unlike std::sort and std::stable_sort, this implementation
does not lead to out-of-bounds memory reads or other undefined
behavior when the predicate is not strict weak ordering.
This makes it possible to use this function in libexpr for
builtins.sort, where an incorrectly implemented comparator
in the user nix code currently can crash and burn the evaluator
by invoking C++ UB.
86785fd9d1 was broken because it was
storing the full path in the MountedSourceAccessor as the `path` field
in the fetcher cache key (i.e. including the
/nix/store/... prefix). Especially in the case of lazy (virtual) store
paths, this didn't work at all because those paths are different every time.
Makes the behavoral change of #13263 without the underlying refactor.
Hopefully this clearly safe from a perf and GC perspective, and will
make it easier to benchmark #13263.
This overload isn't actually necessary anywhere and
doesn't make much sense. The pointers to `Value`s are
themselves const, but the `Value`s are mutable.
A non-const member function implies that the object itself
can be modified but this doesn't make much sense considering
the return type: `Value * const * `, which is a pointer
to a constant array of pointers to mutable values.
