Stop using `the_repository` in the "serve" subsystem by passing in a
repository when advertising capabilities or serving requests.
Adjust callers accordingly by using `the_repository`. While there may be
some callers that have a repository available in their context, this
trivial conversion allows for easier verification and bubbles up the use
of `the_repository` by one level.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Loosen overly strict ownership check introduced in the recent past,
to keep the promise "cloning a suspicious repository is a safe
first step to inspect it".
* bc/allow-upload-pack-from-other-people:
Allow cloning from repositories owned by another user
Historically, Git has allowed users to clone from an untrusted
repository, and we have documented that this is safe to do so:
`upload-pack` tries to avoid any dangerous configuration options or
hooks from the repository it's serving, making it safe to clone an
untrusted directory and run commands on the resulting clone.
However, this was broken by f4aa8c8bb1 ("fetch/clone: detect dubious
ownership of local repositories", 2024-04-10) in an attempt to make
things more secure. That change resulted in a variety of problems when
cloning locally and over SSH, but it did not change the stated security
boundary. Because the security boundary has not changed, it is safe to
adjust part of the code that patch introduced.
To do that and restore the previous functionality, adjust enter_repo to
take two flags instead of one.
The two bits are
- ENTER_REPO_STRICT: callers that require exact paths (as opposed
to allowing known suffixes like ".git", ".git/.git" to be
omitted) can set this bit. Corresponds to the "strict" parameter
that the flags word replaces.
- ENTER_REPO_ANY_OWNER_OK: callers that are willing to run without
ownership check can set this bit.
The former is --strict-paths option of "git daemon". The latter is
set only by upload-pack, which honors the claimed security boundary.
Note that local clones across ownership boundaries require --no-local so
that upload-pack is used. Document this fact in the manual page and
provide an example.
This patch was based on one written by Junio C Hamano.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For builtins that do not operate on a repository, remove
the #define USE_THE_REPOSITORY.
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of including USE_THE_REPOSITORY_VARIABLE by default on every
builtin, remove it from builtin.h and add it to all the builtins that
include builtin.h (by definition, that means all builtins/*.c).
Also, remove the include statement for repository.h since it gets
brought in through builtin.h.
The next step will be to migrate each builtin
from having to use the_repository.
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to reduce the usage of the global the_repository, add a
parameter to builtin functions that will get passed a repository
variable.
This commit uses UNUSED on most of the builtin functions, as subsequent
commits will modify the actual builtins to pass the repository parameter
down.
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-2.44: (41 commits)
Git 2.44.1
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
...
* 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-2.40: (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
...
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>
When the client sends us "want $oid" lines, we call parse_object($oid)
to get an object struct. It's important to parse the commits because we
need to traverse them in the negotiation phase. But of course we don't
need to hold on to the commit messages for each one.
We've turned off the save_commit_buffer flag in get_common_commits() for
a long time, since f0243f26f6 (git-upload-pack: More efficient usage of
the has_sha1 array, 2005-10-28). That helps with the commits we see
while actually traversing. But:
1. That function is only used by the v0 protocol. I think the v2
protocol's code path leaves the flag on (and thus pays the extra
memory penalty), though I didn't measure it specifically.
2. If the client sends us a bunch of "want" lines, that happens before
the negotiation phase. So we'll hold on to all of those commit
messages. Generally the number of "want" lines scales with the
refs, not with the number of objects in the repo. But a malicious
client could send a lot in order to waste memory.
As an example of (2), if I generate a request to fetch all commits in
git.git like this:
pktline() {
local msg="$*"
printf "%04x%s\n" $((1+4+${#msg})) "$msg"
}
want_commits() {
pktline command=fetch
printf 0001
git cat-file --batch-all-objects --batch-check='%(objectname) %(objecttype)' |
while read oid type; do
test "$type" = "commit" || continue
pktline want $oid
done
pktline done
printf 0000
}
want_commits | GIT_PROTOCOL=version=2 valgrind --tool=massif git-upload-pack . >/dev/null
before this patch upload-pack peaks at ~125MB, and after at ~35MB. The
difference is not coincidentally about the same as the sum of all commit
object sizes as computed by:
git cat-file --batch-all-objects --batch-check='%(objecttype) %(objectsize)' |
perl -alne '$v += $F[1] if $F[0] eq "commit"; END { print $v }'
In a larger repository like linux.git, that number is ~1GB.
In a repository with a full commit-graph file this will have no impact
(and the commit graph would save us from parsing at all, so is a much
better solution!). But it's easy to do, might help a little in
real-world cases (where even if you have a commit graph it might not be
fully up to date), and helps a lot for a worst-case malicious request.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Header files cleanup.
* en/header-split-cache-h-part-3: (28 commits)
fsmonitor-ll.h: split this header out of fsmonitor.h
hash-ll, hashmap: move oidhash() to hash-ll
object-store-ll.h: split this header out of object-store.h
khash: name the structs that khash declares
merge-ll: rename from ll-merge
git-compat-util.h: remove unneccessary include of wildmatch.h
builtin.h: remove unneccessary includes
list-objects-filter-options.h: remove unneccessary include
diff.h: remove unnecessary include of oidset.h
repository: remove unnecessary include of path.h
log-tree: replace include of revision.h with simple forward declaration
cache.h: remove this no-longer-used header
read-cache*.h: move declarations for read-cache.c functions from cache.h
repository.h: move declaration of the_index from cache.h
merge.h: move declarations for merge.c from cache.h
diff.h: move declaration for global in diff.c from cache.h
preload-index.h: move declarations for preload-index.c from elsewhere
sparse-index.h: move declarations for sparse-index.c from cache.h
name-hash.h: move declarations for name-hash.c from cache.h
run-command.h: move declarations for run-command.c from cache.h
...
This also made it clear that several .c files that depended upon path.h
were missing a #include for it; add the missing includes while at it.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since this header showed up in some places besides just #include
statements, update/clean-up/remove those other places as well.
Note that compat/fsmonitor/fsm-path-utils-darwin.c previously got
away with violating the rule that all files must start with an include
of git-compat-util.h (or a short-list of alternate headers that happen
to include it first). This change exposed the violation and caused it
to stop building correctly; fix it by having it include
git-compat-util.h first, as per policy.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Several builtins depend on being able to disable the replace references
so we actually operate on each object individually. These currently do
so by directly mutating the 'read_replace_refs' global.
A future change will move this global into a different place, so it will
be necessary to change all of these lines. However, we can simplify that
transition by abstracting the purpose of these global assignments with a
method call.
We will need to keep this read_replace_refs global forever, as we want
to make sure that we never use replace refs throughout the life of the
process if this method is called. Future changes may present a
repository-scoped version of the variable to represent that repository's
core.useReplaceRefs config value, but a zero-valued read_replace_refs
will always override such a setting.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Dozens of files made use of gettext functions, without explicitly
including gettext.h. This made it more difficult to find which files
could remove a dependence on cache.h. Make C files explicitly include
gettext.h if they are using it.
However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adjust several files to be more explicit about their dependency on
replace-objects to accommodate this change.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix various issues of SYNOPSIS and -h output syntax where:
* Options such as --force were missing entirely
* ...or the short option, such as -f
* We said "opts" or "options", but could instead enumerate
the (small) set of supported options
* Options that were missing entirely (ls-remote's --sort=<key>)
As we can specify "--sort" multiple times (it's backed by a
string-list" it should really be "[(--sort=<key>)...]", which is
what "git for-each-ref" lists it as, but let's leave that issue for
a subsequent cleanup, and stop at making these consistent. Other
"ref-filter.h" users share the same issue, e.g. "git-branch.txt".
* For "verify-tag" and "verify-commit" we were missing the "--raw"
option.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The --advertise-refs documentation in git-upload-pack added in
9812f2136b (upload-pack.c: use parse-options API, 2016-05-31) hasn't
been entirely true ever since v2 support was implemented in
e52449b672 (connect: request remote refs using v2, 2018-03-15). Under
v2 we don't advertise the refs at all, but rather dump the
capabilities header.
This option has always been an obscure internal implementation detail,
it wasn't even documented for git-receive-pack. Since it has exactly
one user let's rename it to --http-backend-info-refs, which is more
accurate and points the reader in the right direction. Let's also
cross-link this from the protocol v1 and v2 documentation.
I'm retaining a hidden --advertise-refs alias in case there's any
external users of this, and making both options hidden to the bash
completion (as with most other internal-only options).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "advertise capabilities" mode of serve.c added in
ed10cb952d (serve: introduce git-serve, 2018-03-15) is only used by
the http-backend.c to call {upload,receive}-pack with the
--advertise-refs parameter. See 42526b478e (Add stateless RPC options
to upload-pack, receive-pack, 2009-10-30).
Let's just make cmd_upload_pack() take the two (v2) or three (v2)
parameters the the v2/v1 servicing functions need directly, and pass
those in via the function signature. The logic of whether daemon mode
is implied by the timeout belongs in the v1 function (only used
there).
Once we split up the "advertise v2 refs" from "serve v2 request" it
becomes clear that v2 never cared about those in combination. The only
time it mattered was for v1 to emit its ref advertisement, in that
case we wanted to emit the smart-http-only "no-done" capability.
Since we only do that in the --advertise-refs codepath let's just have
it set "do_done" itself in v1's upload_pack() just before send_ref(),
at that point --advertise-refs and --stateless-rpc in combination are
redundant (the only user is get_info_refs() in http-backend.c), so we
can just pass in --advertise-refs only.
Since we need to touch all the serve() and advertise_capabilities()
codepaths let's rename them to less clever and obvious names, it's
been suggested numerous times, the latest of which is [1]'s suggestion
for protocol_v2_serve_loop(). Let's go with that.
1. https://lore.kernel.org/git/CAFQ2z_NyGb8rju5CKzmo6KhZXD0Dp21u-BbyCb2aNxLEoSPRJw@mail.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a builtin uses RUN_SETUP to request that git.c enter the repository
directory, we'll get passed in a "prefix" variable with the path to the
original directory. It's important to pass this to parse_options(),
since we may use it to fix up relative OPT_FILENAME() options. Some
builtins don't bother; let's make sure we do so consistently.
There may not be any particular bugs fixed here; OPT_FILENAME is
actually pretty rare, and none of these commands use it directly.
However, this does future-proof us against somebody adding an option
that uses it and creating a subtle bug that only shows up when you're in
a subdirectory of the repository.
In some cases, like hash-object and upload-pack, we don't specify
RUN_SETUP, so we know the prefix will always be empty. It's still worth
passing the variable along to keep the idiom consistent across all
builtins (and of course it protects us if they ever _did_ switch to
using RUN_SETUP).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This was added as a NEEDSWORK in c3c36d7de2 (replace-object:
check_replace_refs is safe in multi repo environment, 2018-04-11),
waiting for a calmer period. Since doing so now doesn't conflict
with anything in 'pu', it seems as good a time as any.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The beginning of the next-gen transfer protocol.
* bw/protocol-v2: (35 commits)
remote-curl: don't request v2 when pushing
remote-curl: implement stateless-connect command
http: eliminate "# service" line when using protocol v2
http: don't always add Git-Protocol header
http: allow providing extra headers for http requests
remote-curl: store the protocol version the server responded with
remote-curl: create copy of the service name
pkt-line: add packet_buf_write_len function
transport-helper: introduce stateless-connect
transport-helper: refactor process_connect_service
transport-helper: remove name parameter
connect: don't request v2 when pushing
connect: refactor git_connect to only get the protocol version once
fetch-pack: support shallow requests
fetch-pack: perform a fetch using v2
upload-pack: introduce fetch server command
push: pass ref prefixes when pushing
fetch: pass ref prefixes when fetching
ls-remote: pass ref prefixes when requesting a remote's refs
transport: convert transport_get_remote_refs to take a list of ref prefixes
...
Teach the client to be able to request a remote's refs using protocol
v2. This is done by having a client issue a 'ls-refs' request to a v2
server.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce protocol_v2, a new value for 'enum protocol_version'.
Subsequent patches will fill in the implementation of protocol_v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to allow for code sharing with the server-side of fetch in
protocol-v2 convert upload-pack to be a builtin.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
