* fixes/2.45.1/2.41:
Revert "fsck: warn about symlink pointing inside a gitdir"
Revert "Add a helper function to compare file contents"
clone: drop the protections where hooks aren't run
tests: verify that `clone -c core.hooksPath=/dev/null` works again
Revert "core.hooksPath: add some protection while cloning"
init: use the correct path of the templates directory again
hook: plug a new memory leak
ci: stop installing "gcc-13" for osx-gcc
ci: avoid bare "gcc" for osx-gcc job
ci: drop mention of BREW_INSTALL_PACKAGES variable
send-email: avoid creating more than one Term::ReadLine object
send-email: drop FakeTerm hack
Revert overly aggressive "layered defence" that went into 2.45.1
and friends, which broke "git-lfs", "git-annex", and other use
cases, so that we can rebuild necessary counterparts in the open.
* jc/fix-2.45.1-and-friends-for-2.39:
Revert "fsck: warn about symlink pointing inside a gitdir"
Revert "Add a helper function to compare file contents"
clone: drop the protections where hooks aren't run
tests: verify that `clone -c core.hooksPath=/dev/null` works again
Revert "core.hooksPath: add some protection while cloning"
init: use the correct path of the templates directory again
hook: plug a new memory leak
ci: stop installing "gcc-13" for osx-gcc
ci: avoid bare "gcc" for osx-gcc job
ci: drop mention of BREW_INSTALL_PACKAGES variable
send-email: avoid creating more than one Term::ReadLine object
send-email: drop FakeTerm hack
This defense-in-depth was intended to protect the clone operation
against future escalations where bugs in `git clone` would allow
attackers to write arbitrary files in the `.git/` directory would allow
for Remote Code Execution attacks via maliciously-placed hooks.
However, it turns out that the `core.hooksPath` protection has
unintentional side effects so severe that they do not justify the
benefit of the protections. For example, it has been reported in
https://lore.kernel.org/git/FAFA34CB-9732-4A0A-87FB-BDB272E6AEE8@alchemists.io/
that the following invocation, which is intended to make `git clone`
safer, is itself broken by that protective measure:
git clone --config core.hooksPath=/dev/null <url>
Since it turns out that the benefit does not justify the cost, let's revert
20f3588efc (core.hooksPath: add some protection while cloning,
2024-03-30).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* 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
...
* 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
...
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>
If execve(2) fails with ENOENT and we report the error, we use the
format "cannot run %s", followed by the actual error message. For other
errors we use "cannot exec '%s'".
Stop making this subtle distinction and use the second format for all
execve(2) errors. This simplifies the code and makes the prefix more
precise by indicating the failed operation. It also allows us to
slightly simplify t1800.16.
On Windows -- which lacks execve(2) -- we already use a single format in
all cases: "cannot spawn %s".
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t1800.16 checks whether an attempt to run a hook script with a missing
executable in its #! line fails and reports that error. The expected
error message differs between platforms. The test handles two common
variants, but on NonStop OS we get a third one: "fatal: cannot exec
'bad-hooks/test-hook': ...", which causes the test to fail there.
We don't really care about the specific message text all that much here.
Use grep and a single regex with alternations to ascertain that we get
an error message (fatal or otherwise) about the failed invocation of the
hook, but don't bother checking if we get the right variant for the
platform the test is running on or whether quoting is done. This looser
check let's the test pass on NonStop OS.
Reported-by: Randall S. Becker <randall.becker@nexbridge.ca>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Expose the "path_to_stdin" API added in the preceding commit in the
"git hook run" command.
For now we won't be using this command interface outside of the tests,
but exposing this functionality makes it easier to test the hook
API. The plan is to use this to extend the "sendemail-validate"
hook[1][2].
1. https://lore.kernel.org/git/ad152e25-4061-9955-d3e6-a2c8b1bd24e7@amd.com
2. https://lore.kernel.org/git/20230120012459.920932-1-michael.strawbridge@amd.com
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tests added in 96e7225b31 (hook: add 'run' subcommand,
2021-12-22) were redirecting to "actual" both in the body of the hook
itself and in the testing code below.
The net result was that the "2>>actual" redirection later in the test
wasn't doing anything. Let's have those redirection do what it looks
like they're doing.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
On Cygwin, when failing to spawn a process using start_command, Git
outputs the same error as on Linux systems, rather than using the
GIT_WINDOWS_NATIVE-specific error output. The WINDOWS test prerequisite
is set in both Cygwin and native Windows environments, which means it's
not appropriate to use to anticipate the error output from
start_command. Instead, use the MINGW test prerequisite, which is only
set for Git in native Windows environments, and not for Cygwin.
Signed-off-by: Adam Dinwoodie <adam@dinwoodie.org>
Helped-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a logic error in a082345372 (hook API: fix v2.36.0 regression:
hooks should be connected to a TTY, 2022-06-07). When it started using
the "ungroup" API added in fd3aaf53f7 (run-command: add an "ungroup"
option to run_process_parallel(), 2022-06-07) it should have made the
same sort of change that fd3aaf53f7 itself made in
"t/helper/test-run-command.c".
The correct way to emit this "Couldn't start" output with "ungroup"
would be:
fprintf(stderr, _("Couldn't start hook '%s'\n"), hook_path);
But we should instead remove the emitting of this output. As the added
test shows we already emit output when we can't run the child. The
"cannot run" output here is emitted by run-command.c's
child_err_spew().
So the addition of the "Couldn't start hook" output here in
96e7225b31 (hook: add 'run' subcommand, 2021-12-22) was always
redundant. For the pre-commit hook we'll now emit exactly the same
output as we did before f443246b9f (commit: convert
{pre-commit,prepare-commit-msg} hook to hook.h, 2021-12-22) (and
likewise for others).
We could at this point add this to the pick_next_hook() callbacks in
hook.c:
assert(!out);
assert(!*pp_task_cb);
And this to notify_start_failure() and notify_hook_finished() (in the
latter case the parameter is called "pp_task_cp"):
assert(!out);
assert(!pp_task_cb);
But let's leave any such instrumentation for some eventual cleanup of
the "ungroup" API.
Reported-by: Ilya K <me@0upti.me>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>
Reviewed-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a regression reported[1] against f443246b9f (commit: convert
{pre-commit,prepare-commit-msg} hook to hook.h, 2021-12-22): Due to
using the run_process_parallel() API in the earlier 96e7225b31 (hook:
add 'run' subcommand, 2021-12-22) we'd capture the hook's stderr and
stdout, and thus lose the connection to the TTY in the case of
e.g. the "pre-commit" hook.
As a preceding commit notes GNU parallel's similar --ungroup option
also has it emit output faster. While we're unlikely to have hooks
that emit truly massive amounts of output (or where the performance
thereof matters) it's still informative to measure the overhead. In a
similar "seq" test we're now ~30% faster:
$ cat .git/hooks/seq-hook; git hyperfine -L rev origin/master,HEAD~0 -s 'make CFLAGS=-O3' './git hook run seq-hook'
#!/bin/sh
seq 100000000
Benchmark 1: ./git hook run seq-hook' in 'origin/master
Time (mean ± σ): 787.1 ms ± 13.6 ms [User: 701.6 ms, System: 534.4 ms]
Range (min … max): 773.2 ms … 806.3 ms 10 runs
Benchmark 2: ./git hook run seq-hook' in 'HEAD~0
Time (mean ± σ): 603.4 ms ± 1.6 ms [User: 573.1 ms, System: 30.3 ms]
Range (min … max): 601.0 ms … 606.2 ms 10 runs
Summary
'./git hook run seq-hook' in 'HEAD~0' ran
1.30 ± 0.02 times faster than './git hook run seq-hook' in 'origin/master'
1. https://lore.kernel.org/git/CA+dzEBn108QoMA28f0nC8K21XT+Afua0V2Qv8XkR8rAeqUCCZw@mail.gmail.com/
Reported-by: Anthony Sottile <asottile@umich.edu>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
[jc: minor fix-up to tests for consistency]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Amend a test added in 96e7225b31 (hook: add 'run' subcommand,
2021-12-22) to use a for-loop instead of a copy/pasting the same test
for the four exit codes we test.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a "test_hook" wrapper similar to the existing "test_config"
wrapper added in d960c47a88 (test-lib: add helper functions for
config, 2011-08-17).
This wrapper:
- Will clean up the hook with "test_when_finished", unless --setup is
provided.
- Will error if we clobber a hook, unless --clobber is provided.
- Takes a name like "update" instead of ".git/hooks/update".
- Accepts -C <dir>, like "test_config" and "test_commit".
By using a wrapper we'll be able to easily change all the hook-related
code that assumes that the template-created ".git/hooks" directory is
created by "init", "clone" etc. once another topic follows-up and
changes the test suite to stop creating trash directories using those
templates.
In addition this will make it easy to have the hooks configured using
the "configuration-based hooks" topic, once we get around to
integrating that. I.e. we'll be able to run the tests in a mode where
we sometimes create a .git/hooks/<name>, and other times create a
script in another location, and point the relevant configuration
snippet to it.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For certain one-shot hooks we'd like to optimistically run them, and
not complain if they don't exist.
This was already supported by the underlying hook.c library, but had
not been exposed via "git hook run". The command version of this will
be used by send-email in a subsequent commit.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to enable hooks to be run as an external process, by a
standalone Git command, or by tools which wrap Git, provide an external
means to run all configured hook commands for a given hook event.
Most of our hooks require more complex functionality than this, but
let's start with the bare minimum required to support our simplest
hooks.
In terms of implementation the usage_with_options() and "goto usage"
pattern here mirrors that of
builtin/{commit-graph,multi-pack-index}.c.
Some of the implementation here, such as a function being named
run_hooks_opt() when it's tasked with running one hook, to using the
run_processes_parallel_tr2() API to run with jobs=1 is somewhere
between a bit odd and and an overkill for the current features of this
"hook run" command and the hook.[ch] API.
This code will eventually be able to run multiple hooks declared in
config in parallel, by starting out with these names and APIs we
reduce the later churn of renaming functions, switching from the
run_command() to run_processes_parallel_tr2() API etc.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
