apply: fix writing behind newly created symbolic links
When writing files git-apply(1) initially makes sure that none of the
files it is about to create are behind a symlink:
```
$ git init repo
Initialized empty Git repository in /tmp/repo/.git/
$ cd repo/
$ ln -s dir symlink
$ git apply - <<EOF
diff --git a/symlink/file b/symlink/file
new file mode 100644
index 0000000..e69de29
EOF
error: affected file 'symlink/file' is beyond a symbolic link
```
This safety mechanism is crucial to ensure that we don't write outside
of the repository's working directory. It can be fooled though when the
patch that is being applied creates the symbolic link in the first
place, which can lead to writing files in arbitrary locations.
Fix this by checking whether the path we're about to create is
beyond a symlink or not. Tightening these checks like this should be
fine as we already have these precautions in Git as explained
above. Ideally, we should update the check we do up-front before
starting to reflect the computed changes to the working tree so that
we catch this case as well, but as part of embargoed security work,
adding an equivalent check just before we try to write out a file
should serve us well as a reasonable first step.
Digging back into history shows that this vulnerability has existed
since at least Git v2.9.0. As Git v2.8.0 and older don't build on my
system anymore I cannot tell whether older versions are affected, as
well.
Reported-by: Joern Schneeweisz <jschneeweisz@gitlab.com> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Harshil-Jani [Thu, 2 Feb 2023 03:51:38 +0000 (03:51 +0000)]
mingw: remove msysGit/MSYS1 support
MSys has long fallen behind MSYS2 in features like Unicode or
x86_64 support or even security bug fixes, and is therefore no
longer used by anyone in the Git developer community. The Git for
Windows project itself started switching from MSys to MSYS2 early
in 2015, i.e. about eight years ago. Let's drop supporting MSys as
a development platform.
Signed-off-by: Harshil-Jani <harshiljani2002@gmail.com> Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
nedalloc was added to fix the slowness of memory allocator. Here
specifically for the MSys2 build there seems to be a duplication of
USE_NED_ALLOCATOR directive. So this patch intends to remove the
duplicate USE_NED_ALLOCATOR and keeping it only into the MSys2 config
section so it still uses the nedalloc.
Signed-off-by: Harshil-Jani <harshiljani2002@gmail.com> Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Wed, 1 Feb 2023 11:39:26 +0000 (06:39 -0500)]
t/lib-httpd: increase ssl key size to 2048 bits
Recent versions of openssl will refuse to work with 1024-bit RSA keys,
as they are considered insecure. I didn't track down the exact version
in which the defaults were tightened, but the Debian-package openssl 3.0
on my system yields:
$ LIB_HTTPD_SSL=1 ./t5551-http-fetch-smart.sh -v -i
[...]
SSL Library Error: error:0A00018F:SSL routines::ee key too small
1..0 # SKIP web server setup failed
This could probably be overcome with configuration, but that's likely
to be a headache (especially if it requires touching /etc/openssl).
Let's just pick a key size that's less outrageously out of date.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Wed, 1 Feb 2023 11:39:06 +0000 (06:39 -0500)]
t/lib-httpd: drop SSLMutex config
The SSL config enabled by setting LIB_HTTPD_SSL does not work with
Apache versions greater than 2.2, as more recent versions complain about
the SSLMutex directive. According to
https://httpd.apache.org/docs/current/upgrading.html:
Directives AcceptMutex, LockFile, RewriteLock, SSLMutex,
SSLStaplingMutex, and WatchdogMutexPath have been replaced with a
single Mutex directive. You will need to evaluate any use of these
removed directives in your 2.2 configuration to determine if they can
just be deleted or will need to be replaced using Mutex.
Deleting this line will just use the system default, which seems
sensible. The original came as part of faa4bc35a0 (http-push: add
regression tests, 2008-02-27), but no specific reason is given there (or
on the mailing list) for its presence.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Wed, 1 Feb 2023 11:38:24 +0000 (06:38 -0500)]
t/lib-httpd: bump required apache version to 2.4
Apache 2.4 has been out since early 2012, almost 11 years. And its
predecessor, 2.2, has been out of support since its last release in
2017, over 5 years ago. The last mention on the mailing list was from
around the same time, in this thread:
We can probably assume that 2.4 is available everywhere. And the stakes
are fairly low, as the worst case is that such a platform would skip the
http tests.
This lets us clean up a few minor version checks in the config file, but
also revert f1f2b45be0 (tests: adjust the configuration for Apache 2.2,
2016-05-09). Its technique isn't _too_ bad, but certainly required a bit
more explanation than the 2.4 version it replaced. I manually confirmed
that the test in t5551 still behaves as expected (if you replace
"cadabra" with "foo", the server correctly rejects the request).
It will also help future patches which will no longer have to deal with
conditional config for this old version.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Wed, 1 Feb 2023 11:37:21 +0000 (06:37 -0500)]
t/lib-httpd: bump required apache version to 2.2
Apache 2.2 was released in 2005, almost 18 years ago. We can probably
assume that people are running a version at least that old (and the
stakes for removing it are fairly low, as the worst case is that they
would not run the http tests against their ancient version).
Dropping support for the older versions cleans up the config file a
little, and will also enable us to bump the required version further
(with more cleanups) in a future patch.
Note that the file actually checks for version 2.1. In apache's
versioning scheme, odd numbered versions are for development and even
numbers are for stable releases. So 2.1 and 2.2 are effectively the same
from our perspective.
Older versions would just fail to start, which would generally cause us
to skip the tests. However, we do have version detection code in
lib-httpd.sh which produces a nicer error message, so let's update that,
too. I didn't bother handling the case of "3.0", etc. Apache has been on
2.x for 21 years, with no signs of bumping the major version. And if
they eventually do, I suspect there will be enough breaking changes that
we'd need to update more than just the numeric version check. We can
worry about that hypothetical when it happens.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Glen Choo [Wed, 1 Feb 2023 02:40:41 +0000 (10:40 +0800)]
docs: document zero bits in index "mode"
Documentation/gitformat-index.txt describes the "mode" as 32 bits, but
only documents 16 bits. Document the missing 16 bits and specify that
'unused' bits must be zero.
Signed-off-by: Glen Choo <chooglen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Mathias Krause [Tue, 31 Jan 2023 18:56:11 +0000 (19:56 +0100)]
grep: fall back to interpreter if JIT memory allocation fails
Under Linux systems with SELinux's 'deny_execmem' or PaX's MPROTECT
enabled, the allocation of PCRE2's JIT rwx memory may be prohibited,
making pcre2_jit_compile() fail with PCRE2_ERROR_NOMEMORY (-48):
Instead of failing hard in this case and making 'git grep' unusable on
such systems, simply fall back to interpreter mode, leading to a much
better user experience.
As having a functional PCRE2 JIT compiler is a legitimate use case for
performance reasons, we'll only do the fallback if the supposedly
available JIT is found to be non-functional by attempting to JIT compile
a very simple pattern. If this fails, JIT is deemed to be non-functional
and we do the interpreter fallback. For all other cases, i.e. the simple
pattern can be compiled but the user provided cannot, we fail hard as we
do now as the reason for the failure must be the pattern itself. To aid
users in helping themselves change the error message to include a hint
about the '(*NO_JIT)' prefix. Also clip the pattern at 64 characters to
ensure the hint will be seen by the user and not internally truncated by
the die() function.
Cc: Carlo Marcelo Arenas Belón <carenas@gmail.com> Signed-off-by: Mathias Krause <minipli@grsecurity.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:19 +0000 (13:29 +0000)]
bundle-uri: test missing bundles with heuristic
The creationToken heuristic uses a different mechanism for downloading
bundles from the "standard" approach. Specifically: it uses a concrete
order based on the creationToken values and attempts to download as few
bundles as possible. It also modifies local config to store a value for
future fetches to avoid downloading bundles, if possible.
However, if any of the individual bundles has a failed download, then
the logic for the ordering comes into question. It is important to avoid
infinite loops, assigning invalid creation token values in config, but
also to be opportunistic as possible when downloading as many bundles as
seem appropriate.
These tests were used to inform the implementation of
fetch_bundles_by_token() in bundle-uri.c, but are being added
independently here to allow focusing on faulty downloads. There may be
more cases that could be added that result in modifications to
fetch_bundles_by_token() as interesting data shapes reveal themselves in
real scenarios.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:18 +0000 (13:29 +0000)]
bundle-uri: store fetch.bundleCreationToken
When a bundle list specifies the "creationToken" heuristic, the Git
client downloads the list and then starts downloading bundles in
descending creationToken order. This process stops as soon as all
downloaded bundles can be applied to the repository (because all
required commits are present in the repository or in the downloaded
bundles).
When checking the same bundle list twice, this strategy requires
downloading the bundle with the maximum creationToken again, which is
wasteful. The creationToken heuristic promises that the client will not
have a use for that bundle if its creationToken value is at most the
previous creationToken value.
To prevent these wasteful downloads, create a fetch.bundleCreationToken
config setting that the Git client sets after downloading bundles. This
value allows skipping that maximum bundle download when this config
value is the same value (or larger).
To test that this works correctly, we can insert some "duplicate"
fetches into existing tests and demonstrate that only the bundle list is
downloaded.
The previous logic for downloading bundles by creationToken worked even
if the bundle list was empty, but now we have logic that depends on the
first entry of the list. Terminate early in the (non-sensical) case of
an empty bundle list.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:17 +0000 (13:29 +0000)]
fetch: fetch from an external bundle URI
When a user specifies a URI via 'git clone --bundle-uri', that URI may
be a bundle list that advertises a 'bundle.heuristic' value. In that
case, the Git client stores a 'fetch.bundleURI' config value storing
that URI.
Teach 'git fetch' to check for this config value and download bundles
from that URI before fetching from the Git remote(s). Likely, the bundle
provider has configured a heuristic (such as "creationToken") that will
allow the Git client to download only a portion of the bundles before
continuing the fetch.
Since this URI is completely independent of the remote server, we want
to be sure that we connect to the bundle URI before creating a
connection to the Git remote. We do not want to hold a stateful
connection for too long if we can avoid it.
To test that this works correctly, extend the previous tests that set
'fetch.bundleURI' to do follow-up fetches. The bundle list is updated
incrementally at each phase to demonstrate that the heuristic avoids
downloading older bundles. This includes the middle fetch downloading
the objects in bundle-3.bundle from the Git remote, and therefore not
needing that bundle in the third fetch.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:16 +0000 (13:29 +0000)]
bundle-uri: drop bundle.flag from design doc
The Implementation Plan section lists a 'bundle.flag' option that is not
documented anywhere else. What is documented elsewhere in the document
and implemented by previous changes is the 'bundle.heuristic' config
key. For now, a heuristic is required to indicate that a bundle list is
organized for use during 'git fetch', and it is also sufficient for all
existing designs.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:15 +0000 (13:29 +0000)]
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>
Derrick Stolee [Tue, 31 Jan 2023 13:29:14 +0000 (13:29 +0000)]
bundle-uri: download in creationToken order
The creationToken heuristic provides an ordering on the bundles
advertised by a bundle list. Teach the Git client to download bundles
differently when this heuristic is advertised.
The bundles in the list are sorted by their advertised creationToken
values, then downloaded in decreasing order. This avoids the previous
strategy of downloading bundles in an arbitrary order and attempting
to apply them (likely failing in the case of required commits) until
discovering the order through attempted unbundling.
During a fresh 'git clone', it may make sense to download the bundles in
increasing order, since that would prevent the need to attempt
unbundling a bundle with required commits that do not exist in our empty
object store. The cost of testing an unbundle is quite low, and instead
the chosen order is optimizing for a future bundle download during a
'git fetch' operation with a non-empty object store.
Since the Git client continues fetching from the Git remote after
downloading and unbundling bundles, the client's object store can be
ahead of the bundle provider's object store. The next time it attempts
to download from the bundle list, it makes most sense to download only
the most-recent bundles until all tips successfully unbundle. The
strategy implemented here provides that short-circuit where the client
downloads a minimal set of bundles.
However, we are not satisfied by the naive approach of downloading
bundles until one successfully unbundles, expecting the earlier bundles
to successfully unbundle now. The example repository in t5558
demonstrates this well:
In this repository, if we already have the objects for bundle-1 and then
try to fetch from this list, the naive approach will fail. bundle-4
requires both bundle-3 and bundle-2, though bundle-3 will successfully
unbundle without bundle-2. Thus, the algorithm needs to keep this in
mind.
A later implementation detail will store the maximum creationToken seen
during such a bundle download, and the client will avoid downloading a
bundle unless its creationToken is strictly greater than that stored
value. For now, if the client seeks to download from an identical
bundle list since its previous download, it will download the
most-recent bundle then stop since its required commits are already in
the object store.
Add tests that exercise this behavior, but we will expand upon these
tests when incremental downloads during 'git fetch' make use of
creationToken values.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change taught Git to parse the bundle.heuristic value,
especially when its value is "creationToken". Now, teach Git to parse
the bundle.<id>.creationToken values on each bundle in a bundle list.
Before implementing any logic based on creationToken values for the
creationToken heuristic, parse and print these values for testing
purposes.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:12 +0000 (13:29 +0000)]
bundle-uri: parse bundle.heuristic=creationToken
The bundle.heuristic value communicates that the bundle list is
organized to make use of the bundle.<id>.creationToken values that may
be provided in the bundle list. Those values will create a total order
on the bundles, allowing the Git client to download them in a specific
order and even remember previously-downloaded bundles by storing the
maximum creation token value.
Before implementing any logic that parses or uses the
bundle.<id>.creationToken values, teach Git to parse the
bundle.heuristic value from a bundle list. We can use 'test-tool
bundle-uri' to print the heuristic value and verify that the parsing
works correctly.
As an extra precaution, create the internal 'heuristics' array to be a
list of (enum, string) pairs so we can iterate through the array entries
carefully, regardless of the enum values.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:11 +0000 (13:29 +0000)]
t5558: add tests for creationToken heuristic
As documented in the bundle URI design doc in 2da14fad8fe (docs:
document bundle URI standard, 2022-08-09), the 'creationToken' member of
a bundle URI allows a bundle provider to specify a total order on the
bundles.
Future changes will allow the Git client to understand these members and
modify its behavior around downloading the bundles in that order. In the
meantime, create tests that add creation tokens to the bundle list. For
now, the Git client correctly ignores these unknown keys.
Create a new test helper function, test_remote_https_urls, which filters
GIT_TRACE2_EVENT output to extract a list of URLs passed to
git-remote-https child processes. This can be used to verify the order
of these requests as we implement the creationToken heuristic. For now,
we need to sort the actual output since the current client does not have
a well-defined order that it applies to the bundles.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:10 +0000 (13:29 +0000)]
bundle: verify using check_connected()
When Git verifies a bundle to see if it is safe for unbundling, it first
looks to see if the prerequisite commits are in the object store. This
is an easy way to "fail fast" but it is not a sufficient check for
updating refs that guarantee closure under reachability. There could
still be issues if those commits are not reachable from the repository's
references. The repository only has guarantees that its object store is
closed under reachability for the objects that are reachable from
references.
Thus, the code in verify_bundle() has previously had the additional
check that all prerequisite commits are reachable from repository
references. This is done via a revision walk from all references,
stopping only if all prerequisite commits are discovered or all commits
are walked. This uses a custom walk to verify_bundle().
This check is more strict than what Git applies to fetched pack-files.
In the fetch case, Git guarantees that the new references are closed
under reachability by walking from the new references until walking
commits that are reachable from repository refs. This is done through
the well-used check_connected() method.
To better align with the restrictions required by 'git fetch',
reimplement this check in verify_bundle() to use check_connected(). This
also simplifies the code significantly.
The previous change added a test that verified the behavior of 'git
bundle verify' and 'git bundle unbundle' in this case, and the error
messages looked like this:
error: Could not read <missing-commit>
fatal: Failed to traverse parents of commit <extant-commit>
However, by changing the revision walk slightly within check_connected()
and using its quiet mode, we can omit those messages. Instead, we get
only this message, tailored to describing the current state of the
repository:
error: some prerequisite commits exist in the object store,
but are not connected to the repository's history
(Line break added here for the commit message formatting, only.)
While this message does not include any object IDs, there is no
guarantee that those object IDs would help the user diagnose what is
going on, as they could be separated from the prerequisite commits by
some distance. At minimum, this situation describes the situation in a
more informative way than the previous error messages.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Tue, 31 Jan 2023 13:29:09 +0000 (13:29 +0000)]
bundle: test unbundling with incomplete history
When verifying a bundle, Git checks first that all prerequisite commits
exist in the object store, then adds an additional check: those
prerequisite commits must be reachable from references in the
repository.
This check is stronger than what is checked for refs being added during
'git fetch', which simply guarantees that the new refs have a complete
history up to the point where it intersects with the current reachable
history.
However, we also do not have any tests that check the behavior under
this condition. Create a test that demonstrates its behavior.
In order to construct a broken history, perform a shallow clone of a
repository with a linear history, but whose default branch ('base') has
a single commit, so dropping the shallow markers leaves a complete
history from that reference. However, the 'tip' reference adds a
shallow commit whose parent is missing in the cloned repository. Trying
to unbundle a bundle with the 'tip' as a prerequisite will succeed past
the object store check and move into the reachability check.
The two errors that are reported are of this form:
error: Could not read <missing-commit>
fatal: Failed to traverse parents of commit <present-commit>
These messages are not particularly helpful for the person running the
unbundle command, but they do prevent the command from succeeding.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Mon, 30 Jan 2023 22:24:22 +0000 (14:24 -0800)]
Merge branch 'jk/hash-object-fsck'
"git hash-object" now checks that the resulting object is well
formed with the same code as "git fsck".
* jk/hash-object-fsck:
fsck: do not assume NUL-termination of buffers
hash-object: use fsck for object checks
fsck: provide a function to fsck buffer without object struct
t: use hash-object --literally when created malformed objects
t7030: stop using invalid tag name
t1006: stop using 0-padded timestamps
t1007: modernize malformed object tests
Derrick Stolee [Fri, 27 Jan 2023 20:06:03 +0000 (20:06 +0000)]
scalar: only warn when background maintenance fails
A user reported issues with 'scalar clone' and 'scalar register' when
working in an environment that had locked down the ability to run
'crontab' or 'systemctl' in that those commands registered as _failures_
instead of opportunistically reporting a success with just a warning
about background maintenance.
As a workaround, they can use GIT_TEST_MAINT_SCHEDULER to fake a
successful background maintenance, but this is not a viable strategy for
long-term.
Update 'scalar register' and 'scalar clone' to no longer fail by
modifying register_dir() to only warn when toggle_maintenance(1) fails.
Since background maintenance is a "nice to have" and not a requirement
for a working repository, it is best to move this from hard error to
gentle warning.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee [Fri, 27 Jan 2023 20:06:02 +0000 (20:06 +0000)]
t921*: test scalar behavior starting maintenance
A user recently reported issues with 'scalar register' and 'scalar
clone' in that they failed when the system had permissions locked down
so both 'crontab' and 'systemctl' commands failed when trying to enable
background maintenance.
This hard error is undesirable, but let's create tests that demonstrate
this behavior before modiying the behavior. We can use
GIT_TEST_MAINT_SCHEDULER to guarantee failure and check the exit code
and error message.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git fetch <group>", when "<group>" of remotes lists the same
remote twice, unnecessarily failed when parallel fetching was
enabled, which has been corrected.
Junio C Hamano [Fri, 27 Jan 2023 16:51:40 +0000 (08:51 -0800)]
Merge branch 'km/send-email-with-v-reroll-count'
"git send-email -v 3" used to be expanded to "git send-email
--validate 3" when the user meant to pass them down to
"format-patch", which has been corrected.
* km/send-email-with-v-reroll-count:
send-email: relay '-v N' to format-patch
John Cai [Thu, 26 Jan 2023 21:21:47 +0000 (21:21 +0000)]
attr: fix instructions on how to check attrs
The instructions in attr.h describing what functions to call to check
attributes is missing the index as the first argument to
git_check_attr(), as well as tree_oid as the second argument.
When 7a400a2c (attr: remove an implicit dependency on the_index,
2018-08-13) started passing an index_state instance to git_check_attr(),
it forgot to update the API documentation in
Documentation/technical/api-gitattributes.txt. Later, 3a1b3415
(attr: move doc to attr.h, 2019-11-17) moved the API documentation to
attr.h as a comment, but still left out the index_state as an argument.
In 47cfc9b (attr: add flag `--source` to work with tree-ish 2023-01-14)
added tree_oid as an optional parameter but was not added to the docs in
attr.h
Fix this to make the documentation in the comment consistent with the
actual function signature.
Signed-off-by: John Cai <johncai86@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:54 +0000 (04:03 +0000)]
rebase: provide better error message for apply options vs. merge config
When config which selects the merge backend (currently,
rebase.autosquash=true or rebase.updateRefs=true) conflicts with other
options on the command line (such as --whitespace=fix), make the error
message specifically call out the config option and specify how to
override that config option on the command line.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:52 +0000 (04:03 +0000)]
rebase: fix formatting of rebase --reapply-cherry-picks option in docs
Commit ce5238a690 ("rebase --keep-base: imply --reapply-cherry-picks",
2022-10-17) accidentally added some blank lines that cause extra
paragraphs about --reapply-cherry-picks to be considered not part of
the documentation of that option. Remove the blank lines to make it
clear we are still discussing --reapply-cherry-picks.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:51 +0000 (04:03 +0000)]
rebase: clarify the OPT_CMDMODE incompatibilities
--edit-todo was documented as being incompatible with any of the options
for the apply backend. However, it is also incompatible with any of the
options for the merge backend, and is incompatible with any options that
are not backend specific as well. The same can be said for --continue,
--skip, --abort, --quit, etc.
This is already somewhat implicitly covered by the synopsis, but since
"[<options>]" in the first two variants are vague it might be easy to
miss this. That might not be a big deal, but since the rebase manpage
has to spend so much verbiage about incompatibility of options, making
a separate section for these options that are incompatible with
everything else seems clearer. Do that, and remove the needless
inclusion of --edit-todo in the explicit incompatibility list.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:50 +0000 (04:03 +0000)]
rebase: add coverage of other incompatible options
The git-rebase manual noted several sets of incompatible options, but
we were missing tests for a few of these. Further, we were missing
code checks for one of these, which could result in command line
options being silently ignored.
Also, note that adding a check for autosquash means that using
--whitespace=fix together with the config setting rebase.autosquash=true
will trigger an error. A subsequent commit will improve the error
message.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:49 +0000 (04:03 +0000)]
rebase: fix incompatiblity checks for --[no-]reapply-cherry-picks
--[no-]reapply-cherry-picks was traditionally only supported by the
sequencer. Support was added for the apply backend, when --keep-base is
also specified, in commit ce5238a690 ("rebase --keep-base: imply
--reapply-cherry-picks", 2022-10-17). Make the code error out when
--[no-]reapply-cherry-picks is specified AND the apply backend is used
AND --keep-base is not specified. Also, clarify a number of comments
surrounding the interaction of these flags.
Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:48 +0000 (04:03 +0000)]
rebase: fix docs about incompatibilities with --root
In commit 5dacd4abdd ("git-rebase.txt: document incompatible options",
2018-06-25), I added notes about incompatibilities between options for
the apply and merge backends. Unfortunately, I inverted the condition
when --root was incompatible with the apply backend. Fix the
documentation, and add a testcase that verifies the documentation
matches the code.
While at it, the documentation for --root also tried to cover some of
the backend differences between the apply and merge backends in relation
to reapplying cherry picks. The information:
* assumed that the apply backend was the default (it isn't anymore)
* was written before --reapply-cherry-picks became an option
* was written before the detailed information on backend differences
All of these factors make the sentence under --root about reapplying
cherry picks contradict information that is now available elsewhere in
the manual, and the other references are correct. So just strike this
sentence.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:47 +0000 (04:03 +0000)]
rebase: remove --allow-empty-message from incompatible opts
--allow-empty-message was turned into a no-op and even documented
as such; the flag is simply ignored. Since the flag is ignored, it
shouldn't be documented as being incompatible with other flags.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:46 +0000 (04:03 +0000)]
rebase: flag --apply and --merge as incompatible
Previously, we flagged options which implied --apply as being
incompatible with options which implied --merge. But if both options
were given explicitly, then we didn't flag the incompatibility. The
same is true with --apply and --interactive. Add the check, and add
some testcases to verify these are also caught.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Wed, 25 Jan 2023 04:03:45 +0000 (04:03 +0000)]
rebase: mark --update-refs as requiring the merge backend
--update-refs is built in terms of the sequencer, which requires the
merge backend. It was already marked as incompatible with the apply
backend in the git-rebase manual, but the code didn't check for this
incompatibility and warn the user. Check and error now.
While at it, fix a typo in t3422...and fix some misleading wording
(most options which used to be am-specific have since been implemented
in the merge backend as well).
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The temporary file .git_signing_key_tmpkArSj7 created by git contains a
valid *public* key. The error message comes from `ssh-keygen -Y sign' and
is caused by a fallback mechanism in ssh-keygen whereby it tries to
interpret .git_signing_key_tmpkArSj7 as a *private* key if it can't find in
the agent [1]. A fix is scheduled to be released in OpenSSH 9.1. All that
needs to be done is to pass an additional backward-compatible option -U to
'ssh-keygen -Y sign' call. With '-U', ssh-keygen always interprets the file
as public key and expects to find the private key in the agent.
As a result, when the private key is missing from the agent, a more accurate
error message gets produced:
Makefiles: change search through $(MAKEFLAGS) for GNU make 4.4
Since GNU make 4.4 the semantics of the $(MAKEFLAGS) variable has
changed in a backward-incompatible way, as its "NEWS" file notes:
Previously only simple (one-letter) options were added to the MAKEFLAGS
variable that was visible while parsing makefiles. Now, all options are
available in MAKEFLAGS. If you want to check MAKEFLAGS for a one-letter
option, expanding "$(firstword -$(MAKEFLAGS))" is a reliable way to return
the set of one-letter options which can be examined via findstring, etc.
This means that $(MAKEFLAGS) now contains long options like
"--jobserver-auth=fifo:<path>" and we have to adapt to that.
Note that the "-" in "-$(MAKEFLAGS)" is critical here, as the variable
will always contain leading whitespace if there are no short options,
but long options are present.
This is a partial backport of 67b36879fc0 (Makefiles: change search
through $(MAKEFLAGS) for GNU make 4.4, 2022-11-30), which had been
applied directly to git/git.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
Taylor Blau [Wed, 25 Jan 2023 00:43:51 +0000 (19:43 -0500)]
dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
When using the dir_iterator API, we first stat(2) the base path, and
then use that as a starting point to enumerate the directory's contents.
If the directory contains symbolic links, we will immediately die() upon
encountering them without the `FOLLOW_SYMLINKS` flag. The same is not
true when resolving the top-level directory, though.
As explained in a previous commit, this oversight in 6f054f9fb3
(builtin/clone.c: disallow `--local` clones with symlinks, 2022-07-28)
can be used as an attack vector to include arbitrary files on a victim's
filesystem from outside of the repository.
Prevent resolving top-level symlinks unless the FOLLOW_SYMLINKS flag is
given, which will cause clones of a repository with a symlink'd
"$GIT_DIR/objects" directory to fail.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Wed, 25 Jan 2023 00:43:48 +0000 (19:43 -0500)]
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.
Taylor Blau [Wed, 25 Jan 2023 00:43:45 +0000 (19:43 -0500)]
t5619: demonstrate clone_local() with ambiguous transport
When cloning a repository, Git must determine (a) what transport
mechanism to use, and (b) whether or not the clone is local.
Since f38aa83f9a (use local cloning if insteadOf makes a local URL,
2014-07-17), the latter check happens after the remote has been
initialized, and references the remote's URL instead of the local path.
This is done to make it possible for a `url.<base>.insteadOf` rule to
convert a remote URL into a local one, in which case the `clone_local()`
mechanism should be used.
However, with a specially crafted repository, Git can be tricked into
using a non-local transport while still setting `is_local` to "1" and
using the `clone_local()` optimization. The below test case
demonstrates such an instance, and shows that it can be used to include
arbitrary (known) paths in the working copy of a cloned repository on a
victim's machine[^1], even if local file clones are forbidden by
`protocol.file.allow`.
This happens in a few parts:
1. We first call `get_repo_path()` to see if the remote is a local
path. If it is, we replace the repo name with its absolute path.
2. We then call `transport_get()` on the repo name and decide how to
access it. If it was turned into an absolute path in the previous
step, then we should always treat it like a file.
3. We use `get_repo_path()` again, and set `is_local` as appropriate.
But it's already too late to rewrite the repo name as an absolute
path, since we've already fed it to the transport code.
The attack works by including a submodule whose URL corresponds to a
path on disk. In the below example, the repository "sub" is reachable
via the dumb HTTP protocol at (something like):
http://127.0.0.1:NNNN/dumb/sub.git
However, the path "http:/127.0.0.1:NNNN/dumb" (that is, a top-level
directory called "http:", then nested directories "127.0.0.1:NNNN", and
"dumb") exists within the repository, too.
To determine this, it first picks the appropriate transport, which is
dumb HTTP. It then uses the remote's URL in order to determine whether
the repository exists locally on disk. However, the malicious repository
also contains an embedded stub repository which is the target of a
symbolic link at the local path corresponding to the "sub" repository on
disk (i.e., there is a symbolic link at "http:/127.0.0.1/dumb/sub.git",
pointing to the stub repository via ".git/modules/sub/../../../repo").
This stub repository fools Git into thinking that a local repository
exists at that URL and thus can be cloned locally. The affected call is
in `get_repo_path()`, which in turn calls `get_repo_path_1()`, which
locates a valid repository at that target.
This then causes Git to set the `is_local` variable to "1", and in turn
instructs Git to clone the repository using its local clone optimization
via the `clone_local()` function.
The exploit comes into play because the stub repository's top-level
"$GIT_DIR/objects" directory is a symbolic link which can point to an
arbitrary path on the victim's machine. `clone_local()` resolves the
top-level "objects" directory through a `stat(2)` call, meaning that we
read through the symbolic link and copy or hardlink the directory
contents at the destination of the link.
In other words, we can get steps (1) and (3) to disagree by leveraging
the dangling symlink to pick a non-local transport in the first step,
and then set is_local to "1" in the third step when cloning with
`--separate-git-dir`, which makes the symlink non-dangling.
This can result in data-exfiltration on the victim's machine when
sensitive data is at a known path (e.g., "/home/$USER/.ssh").
The appropriate fix is two-fold:
- Resolve the transport later on (to avoid using the local
clone optimization with a non-local transport).
- Avoid reading through the top-level "objects" directory when
(correctly) using the clone_local() optimization.
This patch merely demonstrates the issue. The following two patches will
implement each part of the above fix, respectively.
[^1]: Provided that any target directory does not contain symbolic
links, in which case the changes from 6f054f9fb3 (builtin/clone.c:
disallow `--local` clones with symlinks, 2022-07-28) will abort the
clone.
Reported-by: yvvdwf <yvvdwf@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Pratyush Yadav [Tue, 24 Jan 2023 13:13:46 +0000 (14:13 +0100)]
Merge branch 'js/windows-rce'
Fix a Remote Code Execution vulnerability on Windows. This is caused by
the fact that Tcl on Windows always includes the current directory when
looking for an executable. Therefore malicious repositories can ship
with an aspell.exe in their top-level directory which is executed by Git
GUI without giving the user a chance to inspect it first, i.e. running
untrusted code.
This merge fixes CVE-2022-41953.
* js/windows-rce:
Work around Tcl's default `PATH` lookup
Move the `_which` function (almost) to the top
Move is_<platform> functions to the beginning
is_Cygwin: avoid `exec`ing anything
windows: ignore empty `PATH` elements
As per https://www.tcl.tk/man/tcl8.6/TclCmd/exec.html#M23, Tcl's `exec`
function goes out of its way to imitate the highly dangerous path lookup
of `cmd.exe`, but _of course_ only on Windows:
If a directory name was not specified as part of the application
name, the following directories are automatically searched in
order when attempting to locate the application:
The directory from which the Tcl executable was loaded.
The current directory.
The Windows 32-bit system directory.
The Windows home directory.
The directories listed in the path.
The dangerous part is the second item, of course: `exec` _prefers_
executables in the current directory to those that are actually in the
`PATH`.
It is almost as if people wanted to Windows users vulnerable,
specifically.
To avoid that, Git GUI already has the `_which` function that does not
imitate that dangerous practice when looking up executables in the
search path.
However, Git GUI currently fails to use that function e.g. when trying to
execute `aspell` for spell checking.
That is not only dangerous but combined with Tcl's unfortunate default
behavior and with the fact that Git GUI tries to spell-check a
repository just after cloning, leads to a critical Remote Code Execution
vulnerability.
Let's override both `exec` and `open` to always use `_which` instead of
letting Tcl perform the path lookup, to prevent this attack vector.
This addresses CVE-2022-41953.
For more details, see
https://github.com/git-for-windows/git/security/advisories/GHSA-v4px-mx59-w99c
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
We are about to make use of the `_which` function to address
CVE-2022-41953 by overriding Tcl/Tk's unsafe PATH lookup on Windows.
In preparation for that, let's move it close to the top of the file to
make sure that even early `exec` calls that happen during the start-up
of Git GUI benefit from the fix.
This commit is best viewed with `--color-moved`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
The `is_Cygwin` function is used, among other things, to determine
how executables are discovered in the `PATH` list by the `_which` function.
We are about to change the behavior of the `_which` function on Windows
(but not Cygwin): On Windows, we want it to ignore empty elements of the
`PATH` instead of treating them as referring to the current directory
(which is a "legacy feature" according to
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03,
but apparently not explicitly deprecated, the POSIX documentation is
quite unclear on that even if the Cygwin project itself considers it to
be deprecated: https://github.com/cygwin/cygwin/commit/fc74dbf22f5c).
This is important because on Windows, `exec` does something very unsafe
by default (unless we're running a Cygwin version of Tcl, which follows
Unix semantics).
However, we try to `exec` something _inside_ `is_Cygwin` to determine
whether we're running within Cygwin or not, i.e. before we determined
whether we need to handle `PATH` specially or not. That's a Catch-22.
Therefore, and because it is much cleaner anyway, use the
`$::tcl_platform(os)` value which is guaranteed to start with `CYGWIN_`
when running a Cygwin variant of Tcl/Tk, instead of executing `cygpath
--windir`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
When looking up an executable via the `_which` function, Git GUI
imitates the `execlp()` strategy where the environment variable `PATH`
is interpreted as a list of paths in which to search.
For historical reasons, stemming from the olden times when it was
uncommon to download a lot of files from the internet into the current
directory, empty elements in this list are treated as if the current
directory had been specified.
Nowadays, of course, this treatment is highly dangerous as the current
directory often contains files that have just been downloaded and not
yet been inspected by the user. Unix/Linux users are essentially
expected to be very, very careful to simply not add empty `PATH`
elements, i.e. not to make use of that feature.
On Windows, however, it is quite common for `PATH` to contain empty
elements by mistake, e.g. as an unintended left-over entry when an
application was installed from the Windows Store and then uninstalled
manually.
While it would probably make most sense to safe-guard not only Windows
users, it seems to be common practice to ignore these empty `PATH`
elements _only_ on Windows, but not on other platforms.
Sadly, this practice is followed inconsistently between different
software projects, where projects with few, if any, Windows-based
contributors tend to be less consistent or even "blissful" about it.
Here is a non-exhaustive list:
Cygwin:
It specifically "eats" empty paths when converting path lists to
POSIX: https://github.com/cygwin/cygwin/commit/753702223c7d
I.e. it follows the common practice.
PowerShell:
It specifically ignores empty paths when searching the `PATH`.
The reason for this is apparently so self-evident that it is not
even mentioned here:
https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_environment_variables#path-information
I.e. it follows the common practice.
CMD:
Oh my, CMD. Let's just forget about it, nobody in their right
(security) mind takes CMD as inspiration. It is so unsafe by
default that we even planned on dropping `Git CMD` from Git for
Windows altogether, and only walked back on that plan when we
found a super ugly hack, just to keep Git's users secure by
default:
So CMD chooses to hide behind the battle cry "Works as
Designed!" that all too often leaves users vulnerable. CMD is
probably the most prominent project whose lead you want to avoid
following in matters of security.
Win32 API (`CreateProcess()`)
Just like CMD, `CreateProcess()` adheres to the original design
of the path lookup in the name of backward compatibility (see
https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw
for details):
If the file name does not contain a directory path, the
system searches for the executable file in the following
sequence:
1. The directory from which the application loaded.
2. The current directory for the parent process.
[...]
I.e. the Win32 API itself chooses backwards compatibility over
users' safety.
Git LFS:
There have been not one, not two, but three security advisories
about Git LFS executing executables from the current directory by
mistake. As part of one of them, a change was introduced to stop
treating empty `PATH` elements as equivalent to `.`:
https://github.com/git-lfs/git-lfs/commit/7cd7bb0a1f0d
I.e. it follows the common practice.
Go:
Go does not follow the common practice, and you can think about
that what you want:
https://github.com/golang/go/blob/go1.19.3/src/os/exec/lp_windows.go#L114-L135
https://github.com/golang/go/blob/go1.19.3/src/path/filepath/path_windows.go#L108-L137
Git Credential Manager:
It tries to imitate Git LFS, but unfortunately misses the empty
`PATH` element handling. As of time of writing, this is in the
process of being fixed:
https://github.com/GitCredentialManager/git-credential-manager/pull/968
So now that we have established that it is a common practice to ignore
empty `PATH` elements on Windows, let's assess this commit's change
using Schneier's Five-Step Process
(https://www.schneier.com/crypto-gram/archives/2002/0415.html#1):
Step 1: What problem does it solve?
It prevents an entire class of Remote Code Execution exploits via
Git GUI's `Clone` functionality.
Step 2: How well does it solve that problem?
Very well. It prevents the attack vector of luring an unsuspecting
victim into cloning an executable into the worktree root directory
that Git GUI immediately executes.
Step 3: What other security problems does it cause?
Maybe non-security problems: If a project (ab-)uses the unsafe
`PATH` lookup. That would not only be unsafe, though, but
fragile in the first place because it would break when running
in a subdirectory. Therefore I would consider this a scenario
not worth keeping working.
Step 4: What are the costs of this measure?
Almost nil, except for the time writing up this commit message
;-)
Step 5: Given the answers to steps two through four, is the security
measure worth the costs?
Yes. Keeping Git's users Secure By Default is worth it. It's a
tiny price to pay compared to the damages even a single
successful exploit can cost.
So let's follow that common practice in Git GUI, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
Junio C Hamano [Mon, 23 Jan 2023 21:39:51 +0000 (13:39 -0800)]
Merge branch 'rs/use-enhanced-bre-on-macos'
Newer regex library macOS stopped enabling GNU-like enhanced BRE,
where '\(A\|B\)' works as alternation, unless explicitly asked with
the REG_ENHANCED flag. "git grep" now can be compiled to do so, to
retain the old behaviour.
* rs/use-enhanced-bre-on-macos:
use enhanced basic regular expressions on macOS
Junio C Hamano [Mon, 23 Jan 2023 21:39:49 +0000 (13:39 -0800)]
Merge branch 'ab/cache-api-cleanup'
Code clean-up to tighten the use of in-core index in the API.
* ab/cache-api-cleanup:
cache API: add a "INDEX_STATE_INIT" macro/function, add release_index()
read-cache.c: refactor set_new_index_sparsity() for subsequent commit
sparse-index API: BUG() out on NULL ensure_full_index()
sparse-index.c: expand_to_path() can assume non-NULL "istate"
builtin/difftool.c: { 0 }-initialize rather than using memset()
Andrei Rybak [Mon, 23 Jan 2023 09:01:14 +0000 (10:01 +0100)]
Documentation: render dash correctly
Three hyphens are rendered verbatim in documentation, so "--" has to be
used to produce a dash. Fix asciidoc output for dashes. This is
similar to previous commits f0b922473e (Documentation: render special
characters correctly, 2021-07-29) and de82095a95 (doc
hash-function-transition: fix asciidoc output, 2021-02-05).
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rubén Justo [Sun, 22 Jan 2023 01:38:10 +0000 (02:38 +0100)]
bisect: fix "reset" when branch is checked out elsewhere
Since 1d0fa89 (checkout: add --ignore-other-wortrees, 2015-01-03) we
have a safety valve in checkout/switch to prevent the same branch from
being checked out simultaneously in multiple worktrees.
If a branch is bisected in a worktree while also being checked out in
another worktree; when the bisection is finished, checking out the
branch back in the current worktree may fail.
Let's teach bisect to use the "--ignore-other-worktrees" flag.
Signed-off-by: Rubén Justo <rjusto@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Sun, 22 Jan 2023 01:22:00 +0000 (17:22 -0800)]
Merge branch 'ab/bisect-cleanup'
Code clean-up.
* ab/bisect-cleanup:
bisect: no longer try to clean up left-over `.git/head-name` files
bisect: remove Cogito-related code
bisect run: fix the error message
bisect: verify that a bogus option won't try to start a bisection
bisect--helper: make the order consistently `argc, argv`
bisect--helper: simplify exit code computation
Junio C Hamano [Sun, 22 Jan 2023 01:22:00 +0000 (17:22 -0800)]
Merge branch 'tl/ls-tree-code-clean-up'
Code clean-up.
* tl/ls-tree-code-clean-up:
t3104: remove shift code in 'test_ls_tree_format'
ls-tree: cleanup the redundant SPACE
ls-tree: make "line_termination" less generic
ls-tree: fold "show_tree_data" into "cb" struct
ls-tree: use a "struct options"
ls-tree: don't use "show_tree_data" for "fast" callbacks
Junio C Hamano [Sun, 22 Jan 2023 01:22:00 +0000 (17:22 -0800)]
Merge branch 'pb/doc-orig-head'
Document ORIG_HEAD a bit more.
* pb/doc-orig-head:
git-rebase.txt: add a note about 'ORIG_HEAD' being overwritten
revisions.txt: be explicit about commands writing 'ORIG_HEAD'
git-merge.txt: mention 'ORIG_HEAD' in the Description
git-reset.txt: mention 'ORIG_HEAD' in the Description
git-cherry-pick.txt: do not use 'ORIG_HEAD' in example
Junio C Hamano [Sun, 22 Jan 2023 01:21:59 +0000 (17:21 -0800)]
Merge branch 'ar/test-cleanup'
Test clean-up.
* ar/test-cleanup:
t7527: use test_when_finished in 'case insensitive+preserving'
t6422: drop commented out code
t6003: uncomment test '--max-age=c3, --topo-order'
Junio C Hamano [Sun, 22 Jan 2023 01:21:58 +0000 (17:21 -0800)]
Merge branch 'rs/dup-array'
Code cleaning.
* rs/dup-array:
use DUP_ARRAY
add DUP_ARRAY
do full type check in BARF_UNLESS_COPYABLE
factor out BARF_UNLESS_COPYABLE
mingw: make argv2 in try_shell_exec() non-const
Junio C Hamano [Sun, 22 Jan 2023 01:21:58 +0000 (17:21 -0800)]
Merge branch 'jx/t1301-updates'
Test updates.
* jx/t1301-updates:
t1301: do not change $CWD in "shared=all" test case
t1301: use test_when_finished for cleanup
t1301: fix wrong template dir for git-init
Junio C Hamano [Fri, 20 Jan 2023 23:36:21 +0000 (15:36 -0800)]
Merge branch 'jk/curl-avoid-deprecated-api'
Deal with a few deprecation warning from cURL library.
* jk/curl-avoid-deprecated-api:
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
Jeff King [Thu, 19 Jan 2023 23:13:29 +0000 (18:13 -0500)]
fsck: do not assume NUL-termination of buffers
The fsck code operates on an object buffer represented as a pointer/len
combination. However, the parsing of commits and tags is a little bit
loose; we mostly scan left-to-right through the buffer, without checking
whether we've gone past the length we were given.
This has traditionally been OK because the buffers we feed to fsck
always have an extra NUL after the end of the object content, which ends
any left-to-right scan. That has always been true for objects we read
from the odb, and we made it true for incoming index-pack/unpack-objects
checks in a1e920a0a7 (index-pack: terminate object buffers with NUL,
2014-12-08).
However, we recently added an exception: hash-object asks index_fd() to
do fsck checks. That _may_ have an extra NUL (if we read from a pipe
into a strbuf), but it might not (if we read the contents from the
file). Nor can we just teach it to always add a NUL. We may mmap the
on-disk file, which will not have any extra bytes (if it's a multiple of
the page size). Not to mention that this is a rather subtle assumption
for the fsck code to make.
Instead, let's make sure that the fsck parsers don't ever look past the
size of the buffer they've been given. This _almost_ works already,
thanks to earlier work in 4d0d89755e (Make sure fsck_commit_buffer()
does not run out of the buffer, 2014-09-11). The theory there is that we
check up front whether we have the end of header double-newline
separator. And then any left-to-right scanning we do is OK as long as it
stops when it hits that boundary.
However, we later softened that in 84d18c0bcf (fsck: it is OK for a tag
and a commit to lack the body, 2015-06-28), which allows the
double-newline header to be missing, but does require that the header
ends in a newline. That was OK back then, because of the NUL-termination
guarantees (including the one from a1e920a0a7 mentioned above).
Because 84d18c0bcf guarantees that any header line does end in a
newline, we are still OK with most of the left-to-right scanning. We
only need to take care after completing a line, to check that there is
another line (and we didn't run out of buffer).
Most of these checks are just need to check "buffer < buffer_end" (where
buffer is advanced as we parse) before scanning for the next header
line. But here are a few notes:
- we don't technically need to check for remaining buffer before
parsing the very first line ("tree" for a commit, or "object" for a
tag), because verify_headers() rejects a totally empty buffer. But
we'll do so in the name of consistency and defensiveness.
- there are some calls to strchr('\n'). These are actually OK by the
"the final header line must end in a newline" guarantee from
verify_headers(). They will always find that rather than run off the
end of the buffer. Curiously, they do check for a NULL return and
complain, but I believe that condition can never be reached.
However, I converted them to use memchr() with a proper size and
retained the NULL checks. Using memchr() is not much longer and
makes it more obvious what is going on. Likewise, retaining the NULL
checks serves as a defensive measure in case my analysis is wrong.
- commit 9a1a3a4d4c (mktag: allow omitting the header/body \n
separator, 2021-01-05), does check for the end-of-buffer condition,
but does so with "!*buffer", relying explicitly on the NUL
termination. We can accomplish the same thing with a pointer
comparison. I also folded it into the follow-on conditional that
checks the contents of the buffer, for consistency with the other
checks.
- fsck_ident() uses parse_timestamp(), which is based on strtoumax().
That function will happily skip past leading whitespace, including
newlines, which makes it a risk. We can fix this by scanning to the
first digit ourselves, and then using parse_timestamp() to do the
actual numeric conversion.
Note that as a side effect this fixes the fact that we missed
zero-padded timestamps like "<email> 0123" (whereas we would
complain about "<email> 0123"). I doubt anybody cares, but I
mention it here for completeness.
- fsck_tree() does not need any modifications. It relies on
decode_tree_entry() to do the actual parsing, and that function
checks both that there are enough bytes in the buffer to represent
an entry, and that there is a NUL at the appropriate spot (one
hash-length from the end; this may not be the NUL for the entry we
are parsing, but we know that in the worst case, everything from our
current position to that NUL is a filename, so we won't run out of
bytes).
In addition to fixing the code itself, we'd like to make sure our rather
subtle assumptions are not violated in the future. So this patch does
two more things:
- add comments around verify_headers() documenting the link between
what it checks and the memory safety of the callers. I don't expect
this code to be modified frequently, but this may help somebody from
accidentally breaking things.
- add a thorough set of tests covering truncations at various key
spots (e.g., for a "tree $oid" line, in the middle of the word
"tree", right after it, after the space, in the middle of the $oid,
and right at the end of the line. Most of these are fine already (it
is only truncating right at the end of the line that is currently
broken). And some of them are not even possible with the current
code (we parse "tree " as a unit, so truncating before the space is
equivalent). But I aimed here to consider the code a black box and
look for any truncations that would be a problem for a left-to-right
parser.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
projects / thirdparty / git.git / log
