Commit Graph

464 Commits

Author SHA1 Message Date
Junio C Hamano
48440f60a7 Merge branch 'jc/fix-2.45.1-and-friends-for-2.39' into fixes/2.45.1/2.40
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
2024-05-24 12:29:36 -07:00
Johannes Schindelin
873a466ea3 clone: drop the protections where hooks aren't run
As part of the security bug-fix releases v2.39.4, ..., v2.45.1, I
introduced logic to safeguard `git clone` from running hooks that were
installed _during_ the clone operation.

The rationale was that Git's CVE-2024-32002, CVE-2021-21300,
CVE-2019-1354, CVE-2019-1353, CVE-2019-1352, and CVE-2019-1349 should
have been low-severity vulnerabilities but were elevated to
critical/high severity by the attack vector that allows a weakness where
files inside `.git/` can be inadvertently written during a `git clone`
to escalate to a Remote Code Execution attack by virtue of installing a
malicious `post-checkout` hook that Git will then run at the end of the
operation without giving the user a chance to see what code is executed.

Unfortunately, Git LFS uses a similar strategy to install its own
`post-checkout` hook during a `git clone`; In fact, Git LFS is
installing four separate hooks while running the `smudge` filter.

While this pattern is probably in want of being improved by introducing
better support in Git for Git LFS and other tools wishing to register
hooks to be run at various stages of Git's commands, let's undo the
clone protections to unbreak Git LFS-enabled clones.

This reverts commit 8db1e8743c (clone: prevent hooks from running
during a clone, 2024-03-28).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-21 12:33:08 -07:00
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
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
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
Patrick Steinhardt
d1bb66a546 builtin/clone: abort when hardlinked source and target file differ
When performing local clones with hardlinks we refuse to copy source
files which are symlinks as a mitigation for CVE-2022-39253. This check
can be raced by an adversary though by changing the file to a symlink
after we have checked it.

Fix the issue by checking whether the hardlinked destination file
matches the source file and abort in case it doesn't.

This addresses CVE-2024-32021.

Reported-by: Apple Product Security <product-security@apple.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 00:01:25 +02:00
Patrick Steinhardt
150e6b0aed builtin/clone: stop resolving symlinks when copying files
When a user performs a local clone without `--no-local`, then we end up
copying the source repository into the target repository directly. To
optimize this even further, we try to hardlink files into place instead
of copying data over, which helps both disk usage and speed.

There is an important edge case in this context though, namely when we
try to hardlink symlinks from the source repository into the target
repository. Depending on both platform and filesystem the resulting
behaviour here can be different:

  - On macOS and NetBSD, calling link(3P) with a symlink target creates
    a hardlink to the file pointed to by the symlink.

  - On Linux, calling link(3P) instead creates a hardlink to the symlink
    itself.

To unify this behaviour, 36596fd2df (clone: better handle symlinked
files at .git/objects/, 2019-07-10) introduced logic to resolve symlinks
before we try to link(3P) files. Consequently, the new behaviour was to
always create a hard link to the target of the symlink on all platforms.

Eventually though, we figured out that following symlinks like this can
cause havoc when performing a local clone of a malicious repository,
which resulted in CVE-2022-39253. This issue was fixed via 6f054f9fb3
(builtin/clone.c: disallow `--local` clones with symlinks, 2022-07-28),
by refusing symlinks in the source repository.

But even though we now shouldn't ever link symlinks anymore, the code
that resolves symlinks still exists. In the best case the code does not
end up doing anything because there are no symlinks anymore. In the
worst case though this can be abused by an adversary that rewrites the
source file after it has been checked not to be a symlink such that it
actually is a symlink when we call link(3P). Thus, it is still possible
to recreate CVE-2022-39253 due to this time-of-check-time-of-use bug.

Remove the call to `realpath()`. This doesn't yet address the actual
vulnerability, which will be handled in a subsequent commit.

Reported-by: Apple Product Security <product-security@apple.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 00:01:25 +02:00
Junio C Hamano
72972ea0b9 Merge branch 'ab/various-leak-fixes'
Leak fixes.

* ab/various-leak-fixes:
  push: free_refs() the "local_refs" in set_refspecs()
  push: refactor refspec_append_mapped() for subsequent leak-fix
  receive-pack: release the linked "struct command *" list
  grep API: plug memory leaks by freeing "header_list"
  grep.c: refactor free_grep_patterns()
  builtin/merge.c: free "&buf" on "Your local changes..." error
  builtin/merge.c: use fixed strings, not "strbuf", fix leak
  show-branch: free() allocated "head" before return
  commit-graph: fix a parse_options_concat() leak
  http-backend.c: fix cmd_main() memory leak, refactor reg{exec,free}()
  http-backend.c: fix "dir" and "cmd_arg" leaks in cmd_main()
  worktree: fix a trivial leak in prune_worktrees()
  repack: fix leaks on error with "goto cleanup"
  name-rev: don't xstrdup() an already dup'd string
  various: add missing clear_pathspec(), fix leaks
  clone: use free() instead of UNLEAK()
  commit-graph: use free_commit_graph() instead of UNLEAK()
  bundle.c: don't leak the "args" in the "struct child_process"
  tests: mark tests as passing with SANITIZE=leak
2023-02-22 14:55:45 -08:00
Junio C Hamano
4f59836451 Merge branch 'ds/bundle-uri-5'
The bundle-URI subsystem adds support for creation-token heuristics
to help incremental fetches.

* ds/bundle-uri-5:
  bundle-uri: test missing bundles with heuristic
  bundle-uri: store fetch.bundleCreationToken
  fetch: fetch from an external bundle URI
  bundle-uri: drop bundle.flag from design doc
  clone: set fetch.bundleURI if appropriate
  bundle-uri: download in creationToken order
  bundle-uri: parse bundle.<id>.creationToken values
  bundle-uri: parse bundle.heuristic=creationToken
  t5558: add tests for creationToken heuristic
  bundle: verify using check_connected()
  bundle: test unbundling with incomplete history
2023-02-15 17:11:52 -08:00
Junio C Hamano
c867e4fa18 Sync with Git 2.39.2 2023-02-13 17:03:55 -08:00
Ævar Arnfjörð Bjarmason
81e5c39cf6 clone: use free() instead of UNLEAK()
Change an UNLEAK() added in 0c4542738e (clone: free or UNLEAK further
pointers when finished, 2021-03-14) to use a "to_free" pattern
instead. In this case the "repo" can be either this absolute_pathdup()
value, or in the "else if" branch seen in the context the the
"argv[0]" argument to "main()".

We can only free() the value in the former case, hence the "to_free"
pattern.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-06 15:34:37 -08:00
Johannes Schindelin
3aef76ffd4 Sync with 2.38.4
* maint-2.38:
  Git 2.38.4
  Git 2.37.6
  Git 2.36.5
  Git 2.35.7
  Git 2.34.7
  http: support CURLOPT_PROTOCOLS_STR
  http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
  http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
  Git 2.33.7
  Git 2.32.6
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:43:39 +01:00
Johannes Schindelin
6487e9c459 Sync with 2.37.6
* maint-2.37:
  Git 2.37.6
  Git 2.36.5
  Git 2.35.7
  Git 2.34.7
  http: support CURLOPT_PROTOCOLS_STR
  http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
  http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
  Git 2.33.7
  Git 2.32.6
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:43:28 +01:00
Johannes Schindelin
16004682f9 Sync with 2.36.5
* maint-2.36:
  Git 2.36.5
  Git 2.35.7
  Git 2.34.7
  http: support CURLOPT_PROTOCOLS_STR
  http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
  http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
  Git 2.33.7
  Git 2.32.6
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:38:31 +01:00
Johannes Schindelin
40843216c5 Sync with 2.35.7
* maint-2.35:
  Git 2.35.7
  Git 2.34.7
  http: support CURLOPT_PROTOCOLS_STR
  http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
  http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
  Git 2.33.7
  Git 2.32.6
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:37:52 +01:00
Johannes Schindelin
6a53a59bf9 Sync with 2.34.7
* maint-2.34:
  Git 2.34.7
  http: support CURLOPT_PROTOCOLS_STR
  http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
  http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
  Git 2.33.7
  Git 2.32.6
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:29:44 +01:00
Johannes Schindelin
a7237f5ae9 Sync with 2.33.7
* maint-2.33:
  Git 2.33.7
  Git 2.32.6
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:29:16 +01:00
Johannes Schindelin
87248c5933 Sync with 2.32.6
* maint-2.32:
  Git 2.32.6
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:25:56 +01:00
Johannes Schindelin
aeb93d7da2 Sync with 2.31.7
* maint-2.31:
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:25:08 +01:00
Johannes Schindelin
e14d6b8408 Sync with 2.30.8
* maint-2.30:
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport
2023-02-06 09:24:06 +01:00
Derrick Stolee
4074d3c7e1 clone: set fetch.bundleURI if appropriate
Bundle providers may organize their bundle lists in a way that is
intended to improve incremental fetches, not just initial clones.
However, they do need to state that they have organized with that in
mind, or else the client will not expect to save time by downloading
bundles after the initial clone. This is done by specifying a
bundle.heuristic value.

There are two types of bundle lists: those at a static URI and those
that are advertised from a Git remote over protocol v2.

The new fetch.bundleURI config value applies for static bundle URIs that
are not advertised over protocol v2. If the user specifies a static URI
via 'git clone --bundle-uri', then Git can set this config as a reminder
for future 'git fetch' operations to check the bundle list before
connecting to the remote(s).

For lists provided over protocol v2, we will want to take a different
approach and create a property of the remote itself by creating a
remote.<id>.* type config key. That is not implemented in this change.

Later changes will update 'git fetch' to consume this option.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-31 08:57:48 -08:00
Taylor Blau
cf8f6ce02a clone: delay picking a transport until after get_repo_path()
In the previous commit, t5619 demonstrates an issue where two calls to
`get_repo_path()` could trick Git into using its local clone mechanism
in conjunction with a non-local transport.

That sequence is:

 - the starting state is that the local path https:/example.com/foo is a
   symlink that points to ../../../.git/modules/foo. So it's dangling.

 - get_repo_path() sees that no such path exists (because it's
   dangling), and thus we do not canonicalize it into an absolute path

 - because we're using --separate-git-dir, we create .git/modules/foo.
   Now our symlink is no longer dangling!

 - we pass the url to transport_get(), which sees it as an https URL.

 - we call get_repo_path() again, on the url. This second call was
   introduced by f38aa83f9a (use local cloning if insteadOf makes a
   local URL, 2014-07-17). The idea is that we want to pull the url
   fresh from the remote.c API, because it will apply any aliases.

And of course now it sees that there is a local file, which is a
mismatch with the transport we already selected.

The issue in the above sequence is calling `transport_get()` before
deciding whether or not the repository is indeed local, and not passing
in an absolute path if it is local.

This is reminiscent of a similar bug report in [1], where it was
suggested to perform the `insteadOf` lookup earlier. Taking that
approach may not be as straightforward, since the intent is to store the
original URL in the config, but to actually fetch from the insteadOf
one, so conflating the two early on is a non-starter.

Note: we pass the path returned by `get_repo_path(remote->url[0])`,
which should be the same as `repo_name` (aside from any `insteadOf`
rewrites).

We *could* pass `absolute_pathdup()` of the same argument, which
86521acaca (Bring local clone's origin URL in line with that of a remote
clone, 2008-09-01) indicates may differ depending on the presence of
".git/" for a non-bare repo. That matters for forming relative submodule
paths, but doesn't matter for the second call, since we're just feeding
it to the transport code, which is fine either way.

[1]: https://lore.kernel.org/git/CAMoD=Bi41mB3QRn3JdZL-FGHs4w3C2jGpnJB-CqSndO7FMtfzA@mail.gmail.com/

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-24 16:52:16 -08:00
Junio C Hamano
0903d8bbde Merge branch 'ds/bundle-uri-4'
Bundle URIs part 4.

* ds/bundle-uri-4:
  clone: unbundle the advertised bundles
  bundle-uri: download bundles from an advertised list
  bundle-uri: allow relative URLs in bundle lists
  strbuf: introduce strbuf_strip_file_from_path()
  bundle-uri: serve bundle.* keys from config
  bundle-uri client: add helper for testing server
  transport: rename got_remote_heads
  bundle-uri client: add boolean transfer.bundleURI setting
  clone: request the 'bundle-uri' command when available
  t: create test harness for 'bundle-uri' command
  protocol v2: add server-side "bundle-uri" skeleton
2023-01-02 21:37:18 +09:00
Derrick Stolee
876094ac16 clone: unbundle the advertised bundles
A previous change introduced the transport methods to acquire a bundle
list from the 'bundle-uri' protocol v2 command, when advertised _and_
when the client has chosen to enable the feature.

Teach Git to download and unbundle the data advertised by those bundles
during 'git clone'. This takes place between the ref advertisement and
the object data download, and stateful connections will linger while
the client downloads bundles. In the future, we should consider closing
the remote connection during this process.

Also, since the --bundle-uri option exists, we do not want to mix the
advertised bundles with the user-specified bundles.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-25 16:24:24 +09:00
Ævar Arnfjörð Bjarmason
0cfde740f0 clone: request the 'bundle-uri' command when available
Set up all the needed client parts of the 'bundle-uri' protocol v2
command, without actually doing anything with the bundle URIs.

If the server says it supports 'bundle-uri' teach Git to issue the
'bundle-uri' command after the 'ls-refs' during 'git clone'. The
returned key=value pairs are passed to the bundle list code which is
tested using a different ingest mechanism in t5750-bundle-uri-parse.sh.

At this point, Git does nothing with that bundle list. It will not
download any of the bundles. That will come in a later change after
these protocol bits are finalized.

The no-op client is initially used only by 'git clone' to test the basic
functionality, and eventually will bootstrap the initial download of Git
objects during a fresh clone. The bundle URI client will not be
integrated into other fetches until a mechanism is created to select a
subset of bundles for download.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-25 16:24:23 +09:00
Ævar Arnfjörð Bjarmason
07047d6829 cocci: apply "pending" index-compatibility to some "builtin/*.c"
Apply "index-compatibility.pending.cocci" rule to "builtin/*", but
exclude those where we conflict with in-flight changes.

As a result some of them end up using only "the_index", so let's have
them use the more narrow "USE_THE_INDEX_VARIABLE" rather than
"USE_THE_INDEX_COMPATIBILITY_MACROS".

Manual changes not made by coccinelle, that were squashed in:

* Whitespace-wrap argument lists for repo_hold_locked_index(),
  repo_read_index_preload() and repo_refresh_and_write_index(), in cases
  where the line became too long after the transformation.
* Change "refresh_cache()" to "refresh_index()" in a comment in
  "builtin/update-index.c".
* For those whose call was followed by perror("<macro-name>"), change
  it to perror("<function-name>"), referring to the new function.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-21 12:06:15 +09:00
René Scharfe
ddbb47fde9 replace and remove run_command_v_opt()
Replace the remaining calls of run_command_v_opt() with run_command()
calls and explict struct child_process variables.  This is more verbose,
but not by much overall.  The code becomes more flexible, e.g. it's easy
to extend to conditionally add a new argument.

Then remove the now unused function and its own flag names, simplifying
the run-command API.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-30 14:04:51 -04:00
René Scharfe
0e90673957 use child_process members "args" and "env" directly
Build argument list and environment of child processes by using
struct child_process and populating its members "args" and "env"
directly instead of maintaining separate strvecs and letting
run_command_v_opt() and friends populate these members.  This is
simpler, shorter and slightly more efficient.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-30 14:04:40 -04:00
Junio C Hamano
0d5d92906a Merge branch 'jk/clone-allow-bare-and-o-together' into maint-2.38
"git clone" did not like to see the "--bare" and the "--origin"
options used together without a good reason.

* jk/clone-allow-bare-and-o-together:
  clone: allow "--bare" with "-o"
2022-10-25 17:11:33 -07:00
Junio C Hamano
9c32cfb49c Sync with v2.38.1 2022-10-17 15:46:09 -07:00
Junio C Hamano
7aeb0d4c47 Merge branch 'jk/clone-allow-bare-and-o-together'
"git clone" did not like to see the "--bare" and the "--origin"
options used together without a good reason.

* jk/clone-allow-bare-and-o-together:
  clone: allow "--bare" with "-o"
2022-10-10 10:08:39 -07:00
Taylor Blau
f64d4ca8d6 Sync with 2.37.4
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 20:00:04 -04:00
Taylor Blau
f2798aa404 Sync with 2.36.3
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 19:58:16 -04:00
Taylor Blau
58612f82b6 Sync with 2.35.5
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 17:44:44 -04:00
Taylor Blau
ac8a1db867 Sync with 2.34.5
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 17:43:37 -04:00
Taylor Blau
478a426f14 Sync with 2.33.5
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 17:42:55 -04:00
Taylor Blau
3957f3c84e Sync with 2.32.4
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 17:42:02 -04:00
Taylor Blau
9cbd2827c5 Sync with 2.31.5
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 17:40:44 -04:00
Taylor Blau
122512967e Sync with 2.30.6
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-06 17:39:15 -04:00
Taylor Blau
6f054f9fb3 builtin/clone.c: disallow --local clones with symlinks
When cloning a repository with `--local`, Git relies on either making a
hardlink or copy to every file in the "objects" directory of the source
repository. This is done through the callpath `cmd_clone()` ->
`clone_local()` -> `copy_or_link_directory()`.

The way this optimization works is by enumerating every file and
directory recursively in the source repository's `$GIT_DIR/objects`
directory, and then either making a copy or hardlink of each file. The
only exception to this rule is when copying the "alternates" file, in
which case paths are rewritten to be absolute before writing a new
"alternates" file in the destination repo.

One quirk of this implementation is that it dereferences symlinks when
cloning. This behavior was most recently modified in 36596fd2df (clone:
better handle symlinked files at .git/objects/, 2019-07-10), which
attempted to support `--local` clones of repositories with symlinks in
their objects directory in a platform-independent way.

Unfortunately, this behavior of dereferencing symlinks (that is,
creating a hardlink or copy of the source's link target in the
destination repository) can be used as a component in attacking a
victim by inadvertently exposing the contents of file stored outside of
the repository.

Take, for example, a repository that stores a Dockerfile and is used to
build Docker images. When building an image, Docker copies the directory
contents into the VM, and then instructs the VM to execute the
Dockerfile at the root of the copied directory. This protects against
directory traversal attacks by copying symbolic links as-is without
dereferencing them.

That is, if a user has a symlink pointing at their private key material
(where the symlink is present in the same directory as the Dockerfile,
but the key itself is present outside of that directory), the key is
unreadable to a Docker image, since the link will appear broken from the
container's point of view.

This behavior enables an attack whereby a victim is convinced to clone a
repository containing an embedded submodule (with a URL like
"file:///proc/self/cwd/path/to/submodule") which has a symlink pointing
at a path containing sensitive information on the victim's machine. If a
user is tricked into doing this, the contents at the destination of
those symbolic links are exposed to the Docker image at runtime.

One approach to preventing this behavior is to recreate symlinks in the
destination repository. But this is problematic, since symlinking the
objects directory are not well-supported. (One potential problem is that
when sharing, e.g. a "pack" directory via symlinks, different writers
performing garbage collection may consider different sets of objects to
be reachable, enabling a situation whereby garbage collecting one
repository may remove reachable objects in another repository).

Instead, prohibit the local clone optimization when any symlinks are
present in the `$GIT_DIR/objects` directory of the source repository.
Users may clone the repository again by prepending the "file://" scheme
to their clone URL, or by adding the `--no-local` option to their `git
clone` invocation.

The directory iterator used by `copy_or_link_directory()` must no longer
dereference symlinks (i.e., it *must* call `lstat()` instead of `stat()`
in order to discover whether or not there are symlinks present). This has
no bearing on the overall behavior, since we will immediately `die()` on
encounter a symlink.

Note that t5604.33 suggests that we do support local clones with
symbolic links in the source repository's objects directory, but this
was likely unintentional, or at least did not take into consideration
the problem with sharing parts of the objects directory with symbolic
links at the time. Update this test to reflect which options are and
aren't supported.

Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-01 00:23:38 -04:00
Jeff King
3b910d6e29 clone: allow "--bare" with "-o"
We explicitly forbid the combination of "--bare" with "-o", but there
doesn't seem to be any good reason to do so. The original logic came as
part of e6489a1bdf (clone: do not accept more than one -o option.,
2006-01-22), but that commit does not give any reason.

Furthermore, the equivalent combination via config is allowed:

  git -c clone.defaultRemoteName=foo clone ...

and works as expected. It may be that this combination was considered
useless, because a bare clone does not set remote.origin.fetch (and
hence there is no refs/remotes/origin hierarchy). But it does set
remote.origin.url, and that name is visible to the user via "git fetch
origin", etc.

Let's allow the options to be used together, and switch the "forbid"
test in t5606 to check that we use the requested name. That test came
much later in 349cff76de (clone: add tests for --template and some
disallowed option pairs, 2020-09-29), and does not offer any logic
beyond "let's test what the code currently does".

Reported-by: John A. Leuenhagen <john@zlima12.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-22 12:57:03 -07:00
Junio C Hamano
298a958224 Merge branch 'jk/list-objects-filter-cleanup'
A couple of bugfixes with code clean-up.

* jk/list-objects-filter-cleanup:
  list-objects-filter: convert filter_spec to a strbuf
  list-objects-filter: add and use initializers
  list-objects-filter: handle null default filter spec
  list-objects-filter: don't memset after releasing filter struct
2022-09-19 14:35:24 -07:00
Jeff King
2a01bdedf8 list-objects-filter: add and use initializers
In 7e2619d8ff (list_objects_filter_options: plug leak of filter_spec
strings, 2022-09-08), we noted that the filter_spec string_list was
inconsistent in how it handled memory ownership of strings stored in the
list. The fix there was a bit of a band-aid to set the "strdup_strings"
variable right before adding anything.

That works OK, and it lets the users of the API continue to
zero-initialize the struct. But it makes the code a bit hard to follow
and accident-prone, as any other spots appending the filter_spec need to
think about whether to set the strdup_strings value, too (there's one
such spot in partial_clone_get_default_filter_spec(), which is probably
a possible memory leak).

So let's do that full cleanup now. We'll introduce a
LIST_OBJECTS_FILTER_INIT macro and matching function, and use them as
appropriate (though it is for the "_options" struct, this matches the
corresponding list_objects_filter_release() function).

This is harder than it seems! Many other structs, like
git_transport_data, embed the filter struct. So they need to initialize
it themselves even if the rest of the enclosing struct is OK with
zero-initialization. I found all of the relevant spots by grepping
manually for declarations of list_objects_filter_options. And then doing
so recursively for structs which embed it, and ones which embed those,
and so on.

I'm pretty sure I got everything, but there's no change that would alert
the compiler if any topics in flight added new declarations. To catch
this case, we now double-check in the parsing function that things were
initialized as expected and BUG() if appropriate.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-12 08:38:59 -07:00
Derrick Stolee
65da938916 clone: warn on failure to repo_init()
The --bundle-uri option was added in 5556891961 (clone: add
--bundle-uri option, 2022-08-09), but this also introduced a call to
repo_init() whose return value was ignored. Fix that ignored value by
warning that the bundle URI process could not continue if it failed.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-24 08:46:36 -07:00
Derrick Stolee
e21e663cd1 clone: --bundle-uri cannot be combined with --depth
A previous change added the '--bundle-uri' option, but did not check
if the --depth parameter was included. Since bundles are not compatible
with shallow clones, provide an error message to the user who is
attempting this combination.

I am leaving this as its own change, separate from the one that
implements '--bundle-uri', because this is more of an advisory for the
user. There is nothing wrong with bootstrapping with bundles and then
fetching a shallow clone. However, that is likely going to involve too
much work for the client _and_ the server. The client will download all
of this bundle information containing the full history of the
repository only to ignore most of it. The server will get a shallow
fetch request, but with a list of haves that might cause a more painful
computation of that shallow pack-file.

Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-10 14:07:37 -07:00
Derrick Stolee
5556891961 clone: add --bundle-uri option
Cloning a remote repository is one of the most expensive operations in
Git. The server can spend a lot of CPU time generating a pack-file for
the client's request. The amount of data can clog the network for a long
time, and the Git protocol is not resumable. For users with poor network
connections or are located far away from the origin server, this can be
especially painful.

Add a new '--bundle-uri' option to 'git clone' to bootstrap a clone from
a bundle. If the user is aware of a bundle server, then they can tell
Git to bootstrap the new repository with these bundles before fetching
the remaining objects from the origin server.

Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-10 14:07:37 -07:00
Junio C Hamano
de28459136 Merge branch 'jk/clone-unborn-confusion' into maint
"git clone" from a repository with some ref whose HEAD is unborn
did not set the HEAD in the resulting repository correctly, which
has been corrected.
source: <YsdyLS4UFzj0j/wB@coredump.intra.peff.net>

* jk/clone-unborn-confusion:
  clone: move unborn head creation to update_head()
  clone: use remote branch if it matches default HEAD
  clone: propagate empty remote HEAD even with other branches
  clone: drop extra newline from warning message
2022-08-05 15:51:35 -07:00
Junio C Hamano
cf92cb29e9 Merge branch 'jk/clone-unborn-confusion'
"git clone" from a repository with some ref whose HEAD is unborn
did not set the HEAD in the resulting repository correctly, which
has been corrected.

* jk/clone-unborn-confusion:
  clone: move unborn head creation to update_head()
  clone: use remote branch if it matches default HEAD
  clone: propagate empty remote HEAD even with other branches
  clone: drop extra newline from warning message
2022-07-19 16:40:17 -07:00
Jeff King
daf7898abb clone: move unborn head creation to update_head()
Prior to 4f37d45706 (clone: respect remote unborn HEAD, 2021-02-05),
creation of the local HEAD was always done in update_head(). That commit
added code to handle an unborn head in an empty repository, and just did
all symref creation and config setup there.

This makes the code flow a little bit confusing, especially as new
corner cases have been covered (like the previous commit to match our
default branch name to a non-HEAD remote branch).

Let's move the creation of the unborn symref into update_head(). This
matches the other HEAD-creation cases, and now the logic is consistently
separated: the main cmd_clone() function only examines the situation and
sets variables based on what it finds, and update_head() actually
performs the update.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-11 13:32:37 -07:00