21791 Commits

Author SHA1 Message Date
Johannes Schindelin
e5e6663e69 Sync with 2.43.4
* maint-2.43: (40 commits)
  Git 2.43.4
  Git 2.42.2
  Git 2.41.1
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  ...
2024-04-19 12:38:54 +02:00
Johannes Schindelin
8e97ec3662 Sync with 2.42.2
* maint-2.42: (39 commits)
  Git 2.42.2
  Git 2.41.1
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  has_dir_name(): do not get confused by characters < '/'
  ...
2024-04-19 12:38:50 +02:00
Johannes Schindelin
be348e9815 Sync with 2.41.1
* maint-2.41: (38 commits)
  Git 2.41.1
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  has_dir_name(): do not get confused by characters < '/'
  docs: document security issues around untrusted .git dirs
  ...
2024-04-19 12:38:46 +02:00
Johannes Schindelin
f5b2af06f5 Sync with 2.40.2
* maint-2.40: (39 commits)
  Git 2.40.2
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  has_dir_name(): do not get confused by characters < '/'
  docs: document security issues around untrusted .git dirs
  upload-pack: disable lazy-fetching by default
  ...
2024-04-19 12:38:42 +02:00
Johannes Schindelin
93a88f42db Sync with 2.39.4
* maint-2.39: (38 commits)
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  has_dir_name(): do not get confused by characters < '/'
  docs: document security issues around untrusted .git dirs
  upload-pack: disable lazy-fetching by default
  fetch/clone: detect dubious ownership of local repositories
  ...
2024-04-19 12:38:37 +02:00
Johannes Schindelin
9e65df5eab Merge branch 'ownership-checks-in-local-clones'
This topic addresses two CVEs:

- CVE-2024-32020:

  Local clones may end up hardlinking files into the target repository's
  object database when source and target repository reside on the same
  disk. If the source repository is owned by a different user, then
  those hardlinked files may be rewritten at any point in time by the
  untrusted user.

- CVE-2024-32021:

  When cloning a local source repository that contains symlinks via the
  filesystem, Git may create hardlinks to arbitrary user-readable files
  on the same filesystem as the target repository in the objects/
  directory.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-19 12:38:32 +02:00
Johannes Schindelin
a33fea0886 fsck: warn about symlink pointing inside a gitdir
In the wake of fixing a vulnerability where `git clone` mistakenly
followed a symbolic link that it had just written while checking out
files, writing into a gitdir, let's add some defense-in-depth by
teaching `git fsck` to report symbolic links stored in its trees that
point inside `.git/`.

Even though the Git project never made any promises about the exact
shape of the `.git/` directory's contents, there are likely repositories
out there containing symbolic links that point inside the gitdir. For
that reason, let's only report these as warnings, not as errors.
Security-conscious users are encouraged to configure
`fsck.symlinkPointsToGitDir = error`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-19 12:38:25 +02:00
Johannes Schindelin
20f3588efc core.hooksPath: add some protection while cloning
Quite frequently, when vulnerabilities were found in Git's (quite
complex) clone machinery, a relatively common way to escalate the
severity was to trick Git into running a hook which is actually a script
that has just been laid on disk as part of that clone. This constitutes
a Remote Code Execution vulnerability, the highest severity observed in
Git's vulnerabilities so far.

Some previously-fixed vulnerabilities allowed malicious repositories to
be crafted such that Git would check out files not in the worktree, but
in, say, a submodule's `<git>/hooks/` directory.

A vulnerability that "merely" allows to modify the Git config would
allow a related attack vector, to manipulate Git into looking in the
worktree for hooks, e.g. redirecting the location where Git looks for
hooks, via setting `core.hooksPath` (which would be classified as
CWE-427: Uncontrolled Search Path Element and CWE-114: Process Control,
for more details see https://cwe.mitre.org/data/definitions/427.html and
https://cwe.mitre.org/data/definitions/114.html).

To prevent that attack vector, let's error out and complain loudly if an
active `core.hooksPath` configuration is seen in the repository-local
Git config during a `git clone`.

There is one caveat: This changes Git's behavior in a slightly
backwards-incompatible manner. While it is probably a rare scenario (if
it exists at all) to configure `core.hooksPath` via a config in the Git
templates, it _is_ conceivable that some valid setup requires this to
work. In the hopefully very unlikely case that a user runs into this,
there is an escape hatch: set the `GIT_CLONE_PROTECTION_ACTIVE=false`
environment variable. Obviously, this should be done only with utmost
caution.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-19 12:38:24 +02:00
Johannes Schindelin
4412a04fe6 init.templateDir: consider this config setting protected
The ability to configuring the template directory is a delicate feature:
It allows defining hooks that will be run e.g. during a `git clone`
operation, such as the `post-checkout` hook.

As such, it is of utmost importance that Git would not allow that config
setting to be changed during a `git clone` by mistake, allowing an
attacker a chance for a Remote Code Execution, allowing attackers to run
arbitrary code on unsuspecting users' machines.

As a defense-in-depth measure, to prevent minor vulnerabilities in the
`git clone` code from ballooning into higher-serverity attack vectors,
let's make this a protected setting just like `safe.directory` and
friends, i.e. ignore any `init.templateDir` entries from any local
config.

Note: This does not change the behavior of any recursive clone (modulo
bugs), as the local repository config is not even supposed to be written
while cloning the superproject, except in one scenario: If a config
template is configured that sets the template directory. This might be
done because `git clone --recurse-submodules --template=<directory>`
does not pass that template directory on to the submodules'
initialization.

Another scenario where this commit changes behavior is where
repositories are _not_ cloned recursively, and then some (intentional,
benign) automation configures the template directory to be used before
initializing the submodules.

So the caveat is that this could theoretically break existing processes.

In both scenarios, there is a way out, though: configuring the template
directory via the environment variable `GIT_TEMPLATE_DIR`.

This change in behavior is a trade-off between security and
backwards-compatibility that is struck in favor of security.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-19 12:38:24 +02:00
Johannes Schindelin
8db1e8743c clone: prevent hooks from running during a clone
Critical security issues typically combine relatively common
vulnerabilities such as case confusion in file paths with other
weaknesses in order to raise the severity of the attack.

One such weakness that has haunted the Git project in many a
submodule-related CVE is that any hooks that are found are executed
during a clone operation. Examples are the `post-checkout` and
`fsmonitor` hooks.

However, Git's design calls for hooks to be disabled by default, as only
disabled example hooks are copied over from the templates in
`<prefix>/share/git-core/templates/`.

As a defense-in-depth measure, let's prevent those hooks from running.

Obviously, administrators can choose to drop enabled hooks into the
template directory, though, _and_ it is also possible to override
`core.hooksPath`, in which case the new check needs to be disabled.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-19 12:38:23 +02:00
Johannes Schindelin
584de0b4c2 Add a helper function to compare file contents
In the next commit, Git will learn to disallow hooks during `git clone`
operations _except_ when those hooks come from the templates (which are
inherently supposed to be trusted). To that end, we add a function to
compare the contents of two files.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-19 12:38:19 +02:00
Johannes Schindelin
31572dc420 clone: when symbolic links collide with directories, keep the latter
When recursively cloning a repository with submodules, we must ensure
that the submodules paths do not suddenly contain symbolic links that
would let Git write into unintended locations. We just plugged that
vulnerability, but let's add some more defense-in-depth.

Since we can only keep one item on disk if multiple index entries' paths
collide, we may just as well avoid keeping a symbolic link (because that
would allow attack vectors where Git follows those links by mistake).

Technically, we handle more situations than cloning submodules into
paths that were (partially) replaced by symbolic links. This provides
defense-in-depth in case someone finds a case-folding confusion
vulnerability in the future that does not even involve submodules.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:30:08 +02:00
Johannes Schindelin
e4930e86c0 t5510: verify that D/F confusion cannot lead to an RCE
The most critical vulnerabilities in Git lead to a Remote Code Execution
("RCE"), i.e. the ability for an attacker to have malicious code being
run as part of a Git operation that is not expected to run said code,
such has hooks delivered as part of a `git clone`.

A couple of parent commits ago, a bug was fixed that let Git be confused
by the presence of a path `a-` to mistakenly assume that a directory
`a/` can safely be created without removing an existing `a` that is a
symbolic link.

This bug did not represent an exploitable vulnerability on its
own; Let's make sure it stays that way.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:30:06 +02:00
Johannes Schindelin
e8d0608944 submodule: require the submodule path to contain directories only
Submodules are stored in subdirectories of their superproject. When
these subdirectories have been replaced with symlinks by a malicious
actor, all kinds of mayhem can be caused.

This _should_ not be possible, but many CVEs in the past showed that
_when_ possible, it allows attackers to slip in code that gets executed
during, say, a `git clone --recursive` operation.

Let's add some defense-in-depth to disallow submodule paths to have
anything except directories in them.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:30:04 +02:00
Johannes Schindelin
9706576133 submodules: submodule paths must not contain symlinks
When creating a submodule path, we must be careful not to follow
symbolic links. Otherwise we may follow a symbolic link pointing to
a gitdir (which are valid symbolic links!) e.g. while cloning.

On case-insensitive filesystems, however, we blindly replace a directory
that has been created as part of the `clone` operation with a symlink
when the path to the latter differs only in case from the former's path.

Let's simply avoid this situation by expecting not ever having to
overwrite any existing file/directory/symlink upon cloning. That way, we
won't even replace a directory that we just created.

This addresses CVE-2024-32002.

Reported-by: Filip Hejsek <filip.hejsek@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:30:02 +02:00
Filip Hejsek
9cf8547320 clone: prevent clashing git dirs when cloning submodule in parallel
While it is expected to have several git dirs within the `.git/modules/`
tree, it is important that they do not interfere with each other. For
example, if one submodule was called "captain" and another submodule
"captain/hooks", their respective git dirs would clash, as they would be
located in `.git/modules/captain/` and `.git/modules/captain/hooks/`,
respectively, i.e. the latter's files could clash with the actual Git
hooks of the former.

To prevent these clashes, and in particular to prevent hooks from being
written and then executed as part of a recursive clone, we introduced
checks as part of the fix for CVE-2019-1387 in a8dee3ca61 (Disallow
dubiously-nested submodule git directories, 2019-10-01).

It is currently possible to bypass the check for clashing submodule
git dirs in two ways:

1. parallel cloning
2. checkout --recurse-submodules

Let's check not only before, but also after parallel cloning (and before
checking out the submodule), that the git dir is not clashing with
another one, otherwise fail. This addresses the parallel cloning issue.

As to the parallel checkout issue: It requires quite a few manual steps
to create clashing git dirs because Git itself would refuse to
initialize the inner one, as demonstrated by the test case.

Nevertheless, let's teach the recursive checkout (namely, the
`submodule_move_head()` function that is used by the recursive checkout)
to be careful to verify that it does not use a clashing git dir, and if
it does, disable it (by deleting the `HEAD` file so that subsequent Git
calls won't recognize it as a git dir anymore).

Note: The parallel cloning test case contains a `cat err` that proved to
be highly useful when analyzing the racy nature of the operation (the
operation can fail with three different error messages, depending on
timing), and was left on purpose to ease future debugging should the
need arise.

Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:30:01 +02:00
Filip Hejsek
b20c10fd9b t7423: add tests for symlinked submodule directories
Submodule operations must not follow symlinks in working tree, because
otherwise files might be written to unintended places, leading to
vulnerabilities.

Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:30:00 +02:00
Filip Hejsek
c30a574a0b has_dir_name(): do not get confused by characters < '/'
There is a bug in directory/file ("D/F") conflict checking optimization:
It assumes that such a conflict cannot happen if a newly added entry's
path is lexicgraphically "greater than" the last already-existing index
entry _and_ contains a directory separator that comes strictly after the
common prefix (`len > len_eq_offset`).

This assumption is incorrect, though: `a-` sorts _between_ `a` and
`a/b`, their common prefix is `a`, the slash comes after the common
prefix, and there is still a file/directory conflict.

Let's re-design this logic, taking these facts into consideration:

- It is impossible for a file to sort after another file with whose
  directory it conflicts because the trailing NUL byte is always smaller
  than any other character.

- Since there are quite a number of ASCII characters that sort before
  the slash (e.g. `-`, `.`, the space character), looking at the last
  already-existing index entry is not enough to determine whether there
  is a D/F conflict when the first character different from the
  existing last index entry's path is a slash.

  If it is not a slash, there cannot be a file/directory conflict.

  And if the existing index entry's first different character is a
  slash, it also cannot be a file/directory conflict because the
  optimization requires the newly-added entry's path to sort _after_ the
  existing entry's, and the conflicting file's path would not.

So let's fall back to the regular binary search whenever the newly-added
item's path differs in a slash character. If it does not, and it sorts
after the last index entry, there is no D/F conflict and the new index
entry can be safely appended.

This fix also nicely simplifies the logic and makes it much easier to
reason about, while the impact on performance should be negligible:
After this fix, the optimization will be skipped only when index
entry's paths differ in a slash and a space, `!`,  `"`,  `#`,  `$`,
`%`, `&`,  `'`,  | (  `)`,  `*`,  `+`,  `,`,  `-`, or  `.`, which should
be a rare situation.

Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:29:58 +02:00
Jeff King
7b70e9efb1 upload-pack: disable lazy-fetching by default
The upload-pack command tries to avoid trusting the repository in which
it's run (e.g., by not running any hooks and not using any config that
contains arbitrary commands). But if the server side of a fetch or a
clone is a partial clone, then either upload-pack or its child
pack-objects may run a lazy "git fetch" under the hood. And it is very
easy to convince fetch to run arbitrary commands.

The "server" side can be a local repository owned by someone else, who
would be able to configure commands that are run during a clone with the
current user's permissions. This issue has been designated
CVE-2024-32004.

The fix in this commit's parent helps in this scenario, as well as in
related scenarios using SSH to clone, where the untrusted .git directory
is owned by a different user id. But if you received one as a zip file,
on a USB stick, etc, it may be owned by your user but still untrusted.

This has been designated CVE-2024-32465.

To mitigate the issue more completely, let's disable lazy fetching
entirely during `upload-pack`. While fetching from a partial repository
should be relatively rare, it is certainly not an unreasonable workflow.
And thus we need to provide an escape hatch.

This commit works by respecting a GIT_NO_LAZY_FETCH environment variable
(to skip the lazy-fetch), and setting it in upload-pack, but only when
the user has not already done so (which gives us the escape hatch).

The name of the variable is specifically chosen to match what has
already been added in 'master' via e6d5479e7a (git: extend
--no-lazy-fetch to work across subprocesses, 2024-02-27). Since we're
building this fix as a backport for older versions, we could cherry-pick
that patch and its earlier steps. However, we don't really need the
niceties (like a "--no-lazy-fetch" option) that it offers. By using the
same name, everything should just work when the two are eventually
merged, but here are a few notes:

  - the blocking of the fetch in e6d5479e7a is incomplete! It sets
    fetch_if_missing to 0 when we setup the repository variable, but
    that isn't enough. pack-objects in particular will call
    prefetch_to_pack() even if that variable is 0. This patch by
    contrast checks the environment variable at the lowest level before
    we call the lazy fetch, where we can be sure to catch all code
    paths.

    Possibly the setting of fetch_if_missing from e6d5479e7a can be
    reverted, but it may be useful to have. For example, some code may
    want to use that flag to change behavior before it gets to the point
    of trying to start the fetch. At any rate, that's all outside the
    scope of this patch.

  - there's documentation for GIT_NO_LAZY_FETCH in e6d5479e7a. We can
    live without that here, because for the most part the user shouldn't
    need to set it themselves. The exception is if they do want to
    override upload-pack's default, and that requires a separate
    documentation section (which is added here)

  - it would be nice to use the NO_LAZY_FETCH_ENVIRONMENT macro added by
    e6d5479e7a, but those definitions have moved from cache.h to
    environment.h between 2.39.3 and master. I just used the raw string
    literals, and we can replace them with the macro once this topic is
    merged to master.

At least with respect to CVE-2024-32004, this does render this commit's
parent commit somewhat redundant. However, it is worth retaining that
commit as defense in depth, and because it may help other issues (e.g.,
symlink/hardlink TOCTOU races, where zip files are not really an
interesting attack vector).

The tests in t0411 still pass, but now we have _two_ mechanisms ensuring
that the evil command is not run. Let's beef up the existing ones to
check that they failed for the expected reason, that we refused to run
upload-pack at all with an alternate user id. And add two new ones for
the same-user case that both the restriction and its escape hatch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:29:56 +02:00
Johannes Schindelin
f4aa8c8bb1 fetch/clone: detect dubious ownership of local repositories
When cloning from somebody else's repositories, it is possible that,
say, the `upload-pack` command is overridden in the repository that is
about to be cloned, which would then be run in the user's context who
started the clone.

To remind the user that this is a potentially unsafe operation, let's
extend the ownership checks we have already established for regular
gitdir discovery to extend also to local repositories that are about to
be cloned.

This protection extends also to file:// URLs.

The fixes in this commit address CVE-2024-32004.

Note: This commit does not touch the `fetch`/`clone` code directly, but
instead the function used implicitly by both: `enter_repo()`. This
function is also used by `git receive-pack` (i.e. pushes), by `git
upload-archive`, by `git daemon` and by `git http-backend`. In setups
that want to serve repositories owned by different users than the
account running the service, this will require `safe.*` settings to be
configured accordingly.

Also note: there are tiny time windows where a time-of-check-time-of-use
("TOCTOU") race is possible. The real solution to those would be to work
with `fstat()` and `openat()`. However, the latter function is not
available on Windows (and would have to be emulated with rather
expensive low-level `NtCreateFile()` calls), and the changes would be
quite extensive, for my taste too extensive for the little gain given
that embargoed releases need to pay extra attention to avoid introducing
inadvertent bugs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:29:54 +02:00
Filip Hejsek
5c5a4a1c05 t0411: add tests for cloning from partial repo
Cloning from a partial repository must not fetch missing objects into
the partial repository, because that can lead to arbitrary code
execution.

Add a couple of test cases, pretending to the `upload-pack` command (and
to that command only) that it is working on a repository owned by
someone else.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:29:53 +02:00
Patrick Steinhardt
1204e1a824 builtin/clone: refuse local clones of unsafe repositories
When performing a local clone of a repository we end up either copying
or hardlinking the source repository into the target repository. This is
significantly more performant than if we were to use git-upload-pack(1)
and git-fetch-pack(1) to create the new repository and preserves both
disk space and compute time.

Unfortunately though, performing such a local clone of a repository that
is not owned by the current user is inherently unsafe:

  - It is possible that source files get swapped out underneath us while
    we are copying or hardlinking them. While we do perform some checks
    here to assert that we hardlinked the expected file, they cannot
    reliably thwart time-of-check-time-of-use (TOCTOU) style races. It
    is thus possible for an adversary to make us copy or hardlink
    unexpected files into the target directory.

    Ideally, we would address this by starting to use openat(3P),
    fstatat(3P) and friends. Due to platform compatibility with Windows
    we cannot easily do that though. Furthermore, the scope of these
    fixes would likely be quite broad and thus not fit for an embargoed
    security release.

  - Even if we handled TOCTOU-style races perfectly, hardlinking files
    owned by a different user into the target repository is not a good
    idea in general. It is possible for an adversary to rewrite those
    files to contain whatever data they want even after the clone has
    completed.

Address these issues by completely refusing local clones of a repository
that is not owned by the current user. This reuses our existing infra we
have in place via `ensure_valid_ownership()` and thus allows a user to
override the safety guard by adding the source repository path to the
"safe.directory" configuration.

This addresses CVE-2024-32020.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 02:17:40 +02:00
Johannes Schindelin
ea094eec54 Merge branch 'jk/test-lsan-denoise-output'
Tests with LSan from time to time seem to emit harmless message
that makes our tests unnecessarily flakey; we work it around by
filtering the uninteresting output.

* jk/test-lsan-denoise-output:
  test-lib: ignore uninteresting LSan output

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 00:00:54 +02:00
Johannes Schindelin
ef0fc42829 Merge branch 'jk/httpd-test-updates'
Test update.

* jk/httpd-test-updates:
  t/lib-httpd: increase ssl key size to 2048 bits
  t/lib-httpd: drop SSLMutex config
  t/lib-httpd: bump required apache version to 2.4
  t/lib-httpd: bump required apache version to 2.2

This is a backport onto the `maint-2.39` branch, to improve the CI
health of that branch.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
2024-04-16 23:58:40 +02:00
Johannes Schindelin
e3cbeb9673 Merge branch 'jk/http-test-fixes'
Various fix-ups on HTTP tests.

* jk/http-test-fixes:
  t5559: make SSL/TLS the default
  t5559: fix test failures with LIB_HTTPD_SSL
  t/lib-httpd: enable HTTP/2 "h2" protocol, not just h2c
  t/lib-httpd: respect $HTTPD_PROTO in expect_askpass()
  t5551: drop curl trace lines without headers
  t5551: handle v2 protocol in cookie test
  t5551: simplify expected cookie file
  t5551: handle v2 protocol in upload-pack service test
  t5551: handle v2 protocol when checking curl trace
  t5551: stop forcing clone to run with v0 protocol
  t5551: handle HTTP/2 when checking curl trace
  t5551: lower-case headers in expected curl trace
  t5551: drop redundant grep for Accept-Language
  t5541: simplify and move "no empty path components" test
  t5541: stop marking "used receive-pack service" test as v0 only
  t5541: run "used receive-pack service" test earlier

This is a backport onto the `maint-2.39` branch, starting to take care
of making that branch's CI builds healthy again.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
2024-04-16 23:58:06 +02:00
Jeff King
c67cf4c434 test-lib: ignore uninteresting LSan output
When I run the tests in leak-checking mode the same way our CI job does,
like:

  make SANITIZE=leak \
       GIT_TEST_PASSING_SANITIZE_LEAK=true \
       GIT_TEST_SANITIZE_LEAK_LOG=true \
       test

then LSan can racily produce useless entries in the log files that look
like this:

  ==git==3034393==Unable to get registers from thread 3034307.

I think they're mostly harmless based on the source here:

  7e0a52e8e9/compiler-rt/lib/lsan/lsan_common.cpp (L414)

which reads:

    PtraceRegistersStatus have_registers =
        suspended_threads.GetRegistersAndSP(i, &registers, &sp);
    if (have_registers != REGISTERS_AVAILABLE) {
      Report("Unable to get registers from thread %llu.\n", os_id);
      // If unable to get SP, consider the entire stack to be reachable unless
      // GetRegistersAndSP failed with ESRCH.
      if (have_registers == REGISTERS_UNAVAILABLE_FATAL)
        continue;
      sp = stack_begin;
    }

The program itself still runs fine and LSan doesn't cause us to abort.
But test-lib.sh looks for any non-empty LSan logs and marks the test as
a failure anyway, under the assumption that we simply missed the failing
exit code somehow.

I don't think I've ever seen this happen in the CI job, but running
locally using clang-14 on an 8-core machine, I can't seem to make it
through a full run of the test suite without having at least one
failure. And it's a different one every time (though they do seem to
often be related to packing tests, which makes sense, since that is one
of our biggest users of threaded code).

We can hack around this by only counting LSan log files that contain a
line that doesn't match our known-uninteresting pattern.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-16 23:58:04 +02:00
Junio C Hamano
5dc7366297 Merge branch 'la/trailer-cleanups' into maint-2.43
* la/trailer-cleanups:
  trailer: fix comment/cut-line regression with opts->no_divider
2024-02-22 16:09:45 -08:00
Junio C Hamano
58aa645fc0 Merge branch 'la/trailer-cleanups'
Fix to an already-graduated topic.

* la/trailer-cleanups:
  trailer: fix comment/cut-line regression with opts->no_divider
2024-02-19 20:58:06 -08:00
Jeff King
bc47139f4f trailer: fix comment/cut-line regression with opts->no_divider
Commit 97e9d0b78a (trailer: find the end of the log message, 2023-10-20)
combined two code paths for finding the end of the log message. For the
"no_divider" case, we used to use find_trailer_end(), and that has now
been rolled into find_end_of_log_message(). But there's a regression;
that function returns early when no_divider is set, returning the whole
string.

That's not how find_trailer_end() behaved. Although it did skip the
"---" processing (which is what "no_divider" is meant to do), we should
still respect ignored_log_message_bytes(), which covers things like
comments, "commit -v" cut lines, and so on.

The bug is actually in the interpret-trailers command, but the obvious
way to experience it is by running "commit -v" with a "--trailer"
option. The new trailer will be added at the end of the verbose diff,
rather than before it (and consequently will be ignored entirely, since
everything after the diff's intro scissors line is thrown away).

I've added two tests here: one for interpret-trailers directly, which
shows the bug via the parsing routines, and one for "commit -v".

The fix itself is pretty simple: instead of returning early, no_divider
just skips the "---" handling but still calls ignored_log_message_bytes().

Reported-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-19 19:06:18 -08:00
Junio C Hamano
89400c3615 Merge branch 'pb/complete-config'
The command line completion script (in contrib/) learned to
complete configuration variable names better.

* pb/complete-config:
  completion: add and use __git_compute_second_level_config_vars_for_section
  completion: add and use __git_compute_first_level_config_vars_for_section
  completion: complete 'submodule.*' config variables
  completion: add space after config variable names also in Bash 3
2024-02-14 15:36:06 -08:00
Junio C Hamano
c036a145c3 Merge branch 'vn/rebase-with-cherry-pick-authorship'
"git cherry-pick" invoked during "git rebase -i" session lost
the authorship information, which has been corrected.

* vn/rebase-with-cherry-pick-authorship:
  sequencer: unset GIT_CHERRY_PICK_HELP for 'exec' commands
2024-02-14 15:36:05 -08:00
Junio C Hamano
09e0aa64b3 Merge branch 'pw/gc-during-rebase'
The sequencer machinery does not use the ref API and instead
records names of certain objects it needs for its correct operation
in temporary files, which makes these objects susceptible to loss
by garbage collection.  These temporary files have been added as
starting points for reachability analysis to fix this.

* pw/gc-during-rebase:
  prune: mark rebase autostash and orig-head as reachable
2024-02-14 15:36:05 -08:00
Junio C Hamano
bd10c45672 Merge branch 'ps/report-failure-from-git-stash' into maint-2.43
"git stash" sometimes was silent even when it failed due to
unwritable index file, which has been corrected.

* ps/report-failure-from-git-stash:
  builtin/stash: report failure to write to index
2024-02-13 14:44:49 -08:00
Junio C Hamano
5071cb78a3 Merge branch 'jk/diff-external-with-no-index' into maint-2.43
"git diff --no-index file1 file2" segfaulted while invoking the
external diff driver, which has been corrected.

* jk/diff-external-with-no-index:
  diff: handle NULL meta-info when spawning external diff
2024-02-13 14:44:48 -08:00
Junio C Hamano
d982de5d32 Merge branch 'rs/parse-options-with-keep-unknown-abbrev-fix' into maint-2.43
"git diff --no-rename A B" did not disable rename detection but did
not trigger an error from the command line parser.

* rs/parse-options-with-keep-unknown-abbrev-fix:
  parse-options: simplify positivation handling
  parse-options: fully disable option abbreviation with PARSE_OPT_KEEP_UNKNOWN
2024-02-13 14:44:48 -08:00
Junio C Hamano
904ca69428 Merge branch 'en/diffcore-delta-final-line-fix' into maint-2.43
Rename detection logic ignored the final line of a file if it is an
incomplete line.

* en/diffcore-delta-final-line-fix:
  diffcore-delta: avoid ignoring final 'line' of file
2024-02-13 14:44:48 -08:00
Junio C Hamano
908fde12b0 Merge branch 'tc/show-ref-exists-fix' into maint-2.43
Update to a new feature recently added, "git show-ref --exists".

* tc/show-ref-exists-fix:
  builtin/show-ref: treat directory as non-existing in --exists
2024-02-13 14:44:47 -08:00
Junio C Hamano
9115864cb5 Merge branch 'jc/unit-tests-make-relative-fix'
The mechanism to report the filename in the source code, used by
the unit-test machinery, assumed that the compiler expanded __FILE__
to the path to the source given to the $(CC), but some compilers
give full path, breaking the output.  This has been corrected.

* jc/unit-tests-make-relative-fix:
  unit-tests: do show relative file paths on non-Windows, too
2024-02-13 14:31:11 -08:00
Junio C Hamano
3b89ff16aa Merge branch 'tb/multi-pack-reuse-experiment'
Setting `feature.experimental` opts the user into multi-pack reuse
experiment

* tb/multi-pack-reuse-experiment:
  pack-objects: enable multi-pack reuse via `feature.experimental`
  t5332-multi-pack-reuse.sh: extract pack-objects helper functions
2024-02-12 13:16:11 -08:00
Junio C Hamano
d4833b22ab Merge branch 'vd/for-each-ref-sort-with-formatted-timestamp'
"git branch" and friends learned to use the formatted text as
sorting key, not the underlying timestamp value, when the --sort
option is used with author or committer timestamp with a format
specifier (e.g., "--sort=creatordate:format:%H:%M:%S").

* vd/for-each-ref-sort-with-formatted-timestamp:
  ref-filter.c: sort formatted dates by byte value
2024-02-12 13:16:11 -08:00
Junio C Hamano
b3370dd51e Merge branch 'pw/show-ref-pseudorefs'
"git show-ref --verify" did not show things like "CHERRY_PICK_HEAD",
which has been corrected.

* pw/show-ref-pseudorefs:
  t1400: use show-ref to check pseudorefs
  show-ref --verify: accept pseudorefs
2024-02-12 13:16:11 -08:00
Junio C Hamano
70550a2242 Merge branch 'ps/report-failure-from-git-stash'
"git stash" sometimes was silent even when it failed due to
unwritable index file, which has been corrected.

* ps/report-failure-from-git-stash:
  builtin/stash: report failure to write to index
2024-02-12 13:16:11 -08:00
Junio C Hamano
46761378c3 Merge branch 'bk/complete-bisect'
Command line completion support (in contrib/) has been
updated for "git bisect".

* bk/complete-bisect:
  completion: bisect: recognize but do not complete view subcommand
  completion: bisect: complete log opts for visualize subcommand
  completion: new function __git_complete_log_opts
  completion: bisect: complete missing --first-parent and - -no-checkout options
  completion: bisect: complete custom terms and related options
  completion: bisect: complete bad, new, old, and help subcommands
  completion: tests: always use 'master' for default initial branch name
2024-02-12 13:16:10 -08:00
Philippe Blain
6e32f718ff completion: add and use __git_compute_second_level_config_vars_for_section
In a previous commit we removed some hardcoded config variable names from
function __git_complete_config_variable_name in the completion script by
introducing a new function,
__git_compute_first_level_config_vars_for_section.

The remaining hardcoded config variables are "second level"
configuration variables, meaning 'branch.<name>.upstream',
'remote.<name>.url', etc. where <name> is a user-defined name.

Making use of the new existing --config flag to 'git help', add a new
function, __git_compute_second_level_config_vars_for_section. This
function takes as argument a config section name and computes the
corresponding second-level config variables, i.e. those that contain a
'<' which indicates the start of a placeholder. Note that as in
__git_compute_first_level_config_vars_for_section added previsouly, we
use indirect expansion instead of associative arrays to stay compatible
with Bash 3 on which macOS is stuck for licensing reasons.

As explained in the previous commit, we use the existing pattern in the
completion script of using global variables to cache the list of
variables for each section.

Use this new function and the variables it defines in
__git_complete_config_variable_name to remove hardcoded config
variables, and add a test to verify the new function.  Use a single
'case' for all sections with second-level variables names, since the
code for each of them is now exactly the same.

Adjust the name of a test added in a previous commit to reflect that it
now tests the added function.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-12 09:43:42 -08:00
Philippe Blain
1e0ee4087e completion: add and use __git_compute_first_level_config_vars_for_section
The function __git_complete_config_variable_name in the Bash completion
script hardcodes several config variable names. These variables are
those in config sections where user-defined names can appear, such as
"branch.<name>". These sections are treated first by the case statement,
and the two last "catch all" cases are used for other sections, making
use of the __git_compute_config_vars and __git_compute_config_sections
function, which omit listing any variables containing wildcards or
placeholders. Having hardcoded config variables introduces the risk of
the completion code becoming out of sync with the actual config
variables accepted by Git.

To avoid these hardcoded config variables, introduce a new function,
__git_compute_first_level_config_vars_for_section, making use of the
existing __git_config_vars variable. This function takes as argument a
config section name and computes the matching "first level" config
variables for that section, i.e. those _not_ containing any placeholder,
like 'branch.autoSetupMerge, 'remote.pushDefault', etc.  Use this
function and the variables it defines in the 'branch.*', 'remote.*' and
'submodule.*' switches of the case statement instead of hardcoding the
corresponding config variables.  Note that we use indirect expansion to
create a variable for each section, instead of using a single
associative array indexed by section names, because associative arrays
are not supported in Bash 3, on which macOS is stuck for licensing
reasons.

Use the existing pattern in the completion script of using global
variables to cache the list of config variables for each section. The
rationale for such caching is explained in eaa4e6ee2a (Speed up bash
completion loading, 2009-11-17), and the current approach to using and
defining them via 'test -n' is explained in cf0ff02a38 (completion: work
around zsh option propagation bug, 2012-02-02).

Adjust the name of one of the tests added in the previous commit,
reflecting that it now also tests the new function.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-12 09:43:42 -08:00
Philippe Blain
b1d0cc68d1 completion: complete 'submodule.*' config variables
In the Bash completion script, function
__git_complete_config_variable_name completes config variables and has
special logic to deal with config variables involving user-defined
names, like branch.<name>.* and remote.<name>.*.

This special logic is missing for submodule-related config variables.
Add the appropriate branches to the case statement, making use of the
in-tree '.gitmodules' to list relevant submodules.

Add corresponding tests in t9902-completion.sh, making sure we complete
both first level submodule config variables as well as second level
variables involving submodule names.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-12 09:43:42 -08:00
Junio C Hamano
f66286364f unit-tests: do show relative file paths on non-Windows, too
There are compilers other than Visual C that want to show absolute
paths.  Generalize the helper introduced by a2c5e294 (unit-tests: do
show relative file paths, 2023-09-25) so that it can also work with
a path that uses slash as the directory separator, and becomes
almost no-op once one-time preparation finds out that we are using a
compiler that already gives relative paths.  Incidentally, this also
should do the right thing on Windows with a compiler that shows
relative paths but with backslash as the directory separator (if
such a thing exists and is used to build git).

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-12 08:44:22 -08:00
Phillip Wood
bc7f5db896 prune: mark rebase autostash and orig-head as reachable
Rebase records the oid of HEAD before rebasing and the commit created by
"--autostash" in files in the rebase state directory. This means that
the autostash commit is never reachable from any ref or reflog and when
rebasing a detached HEAD the original HEAD can become unreachable if the
user expires HEAD's the reflog while the rebase is running. Fix this by
reading the relevant files when marking reachable commits.

Note that it is possible for the commit recorded in
.git/rebase-merge/amend to be unreachable but pruning that object does
not affect the operation of "git rebase --continue" as we're only
interested in the object id, not in the object itself.

Reported-by: Orgad Shaneh <orgads@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-09 10:04:59 -08:00
Junio C Hamano
5b49c1af03 Merge branch 'jx/sideband-chomp-newline-fix' into maint-2.43
Sideband demultiplexer fixes.

* jx/sideband-chomp-newline-fix:
  pkt-line: do not chomp newlines for sideband messages
  pkt-line: memorize sideband fragment in reader
  test-pkt-line: add option parser for unpack-sideband
2024-02-08 16:22:11 -08:00
Junio C Hamano
fb3ead665b Merge branch 'jk/t1006-cat-file-objectsize-disk' into maint-2.43
Test update.

* jk/t1006-cat-file-objectsize-disk:
  t1006: prefer shell loop to awk for packed object sizes
  t1006: add tests for %(objectsize:disk)
2024-02-08 16:22:11 -08:00