The `%w(width,indent1,indent2)` formatting directive can be used to
rewrap text to a specific width and is designed after git-shortlog(1)'s
`-w` parameter. While the three parameters are all stored as `size_t`
internally, `strbuf_add_wrapped_text()` accepts integers as input. As a
result, the casted integers may overflow. As these now-negative integers
are later on passed to `strbuf_addchars()`, we will ultimately run into
implementation-defined behaviour due to casting a negative number back
to `size_t` again. On my platform, this results in trying to allocate
9000 petabyte of memory.
Fix this overflow by using `cast_size_t_to_int()` so that we reject
inputs that cannot be represented as an integer.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-2.32:
Git 2.32.3
Git 2.31.4
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
* maint-2.31:
Git 2.31.4
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
* maint-2.30:
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
Previous changes introduced a regression which will prevent root for
accessing repositories owned by thyself if using sudo because SUDO_UID
takes precedence.
Loosen that restriction by allowing root to access repositories owned
by both uid by default and without having to add a safe.directory
exception.
A previous workaround that was documented in the tests is no longer
needed so it has been removed together with its specially crafted
prerequisite.
Helped-by: Johanness Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
bdc77d1d68 (Add a function to determine whether a path is owned by the
current user, 2022-03-02) checks for the effective uid of the running
process using geteuid() but didn't account for cases where that user was
root (because git was invoked through sudo or a compatible tool) and the
original uid that repository trusted for its config was no longer known,
therefore failing the following otherwise safe call:
guy@renard ~/Software/uncrustify $ sudo git describe --always --dirty
[sudo] password for guy:
fatal: unsafe repository ('/home/guy/Software/uncrustify' is owned by someone else)
Attempt to detect those cases by using the environment variables that
those tools create to keep track of the original user id, and do the
ownership check using that instead.
This assumes the environment the user is running on after going
privileged can't be tampered with, and also adds code to restrict that
the new behavior only applies if running as root, therefore keeping the
most common case, which runs unprivileged, from changing, but because of
that, it will miss cases where sudo (or an equivalent) was used to change
to another unprivileged user or where the equivalent tool used to raise
privileges didn't track the original id in a sudo compatible way.
Because of compatibility with sudo, the code assumes that uid_t is an
unsigned integer type (which is not required by the standard) but is used
that way in their codebase to generate SUDO_UID. In systems where uid_t
is signed, sudo might be also patched to NOT be unsigned and that might
be able to trigger an edge case and a bug (as described in the code), but
it is considered unlikely to happen and even if it does, the code would
just mostly fail safely, so there was no attempt either to detect it or
prevent it by the code, which is something that might change in the future,
based on expected user feedback.
Reported-by: Guy Maurel <guy.j@maurel.de>
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Randall Becker <rsbecker@nexbridge.com>
Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Suggested-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-2.32:
Git 2.32.1
Git 2.31.2
Git 2.30.3
setup_git_directory(): add an owner check for the top-level directory
Add a function to determine whether a path is owned by the current user
* maint-2.31:
Git 2.31.2
Git 2.30.3
setup_git_directory(): add an owner check for the top-level directory
Add a function to determine whether a path is owned by the current user
* maint-2.30:
Git 2.30.3
setup_git_directory(): add an owner check for the top-level directory
Add a function to determine whether a path is owned by the current user
This function will be used in the next commit to prevent
`setup_git_directory()` from discovering a repository in a directory
that is owned by someone other than the current user.
Note: We cannot simply use `st.st_uid` on Windows just like we do on
Linux and other Unix-like platforms: according to
https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/stat-functions
this field is always zero on Windows (because Windows' idea of a user ID
does not fit into a single numerical value). Therefore, we have to do
something a little involved to replicate the same functionality there.
Also note: On Windows, a user's home directory is not actually owned by
said user, but by the administrator. For all practical purposes, it is
under the user's control, though, therefore we pretend that it is owned
by the user.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
mingw-w64's pthread_unistd.h had a bug that mistakenly (because there is
no support for the *lockfile() functions required[1]) defined
_POSIX_THREAD_SAFE_FUNCTIONS and that was being worked around since
3ecd153a3b (compat/mingw: support MSys2-based MinGW build, 2016-01-14).
The bug was fixed in winphtreads, but as a side effect, leaves the
reentrant functions from time.h no longer visible and therefore breaks
the build.
Since the intention all along was to avoid using the fallback functions,
formalize the use of POSIX by setting the corresponding feature flag and
compile out the implementation for the fallback functions.
[1] https://unix.org/whitepapers/reentrant.html
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linux users may benefit from additional information on how to
avoid ENOMEM from mmap despite the system having enough RAM to
accomodate them. We can't reliably unmap pack windows to work
around the issue since malloc and other library routines may
mmap without our knowledge.
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix typos in documentation, code comments, and RelNotes which repeat
various words. In trivial cases, just delete the duplicated word and
rewrap text, if needed. Reword the affected sentence in
Documentation/RelNotes/1.8.4.txt for it to make sense.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The xsize_t helper aims to safely convert an off_t to a size_t,
erroring out when a file offset is too large to fit into a memory
address. It does this by using two casts:
size_t size = (size_t) len;
if (len != (off_t) size)
... error out ...
On a platform with sizeof(size_t) < sizeof(off_t), this check is safe
and correct. The first cast truncates to a size_t by finding the
remainder modulo SIZE_MAX+1 (see C99 section 6.3.1.3 Signed and
unsigned integers) and the second promotes to an off_t, meaning the
result is true if and only if len is representable as a size_t.
On other platforms, this two-casts strategy still works well (always
succeeds) for len >= 0. But for len < 0, when the first cast succeeds
and produces SIZE_MAX + 1 + len, the resulting value is too large to
be represented as an off_t, so the second cast produces implementation
defined behavior. In practice, it is likely to produce a result of
true despite len not being representable as size_t.
Simplify by replacing with a more straightforward check: compare len
to the relevant bounds and then cast it. (To avoid a -Wsign-compare
warning, after checking that len >= 0, we explicitly convert to a
sufficiently-large unsigned type before comparing to SIZE_MAX.)
In practice, this is not likely to come up since typical callers use
nonnegative len. Still, it's helpful to handle this case to make the
behavior easy to reason about.
Historical note: the original bounds-checking in 46be82dfd0 (xsize_t:
check whether we lose bits, 2010-07-28) did not produce this
implementation-defined behavior, though it still did not handle
negative offsets. It was not until 73560c793a (git-compat-util.h:
xsize_t() - avoid -Wsign-compare warnings, 2017-09-21) introduced the
double cast that the implementation-defined behavior was triggered.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Streamline the codepath to fix the UTF-8 encoding issues in the
argv[] and the prefix on macOS.
* tb/precompose-prefix-simplify:
macOS: precompose startup_info->prefix
precompose_utf8: make precompose_string_if_needed() public
commit 5c327502 (MacOS: precompose_argv_prefix(), 2021-02-03) uses
the function precompose_string_if_needed() internally. It is only
used from precompose_argv_prefix() and therefore static in
compat/precompose_utf8.c
Expose this function, it will be used in the next commit.
While there, allow passing a NULL pointer, which will return NULL.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It does not make sense to make ".gitattributes", ".gitignore" and
".mailmap" symlinks, as they are supposed to be usable from the
object store (think: bare repositories where HEAD:.mailmap etc. are
used). When these files are symbolic links, we used to read the
contents of the files pointed by them by mistake, which has been
corrected.
* jk/open-dotgitx-with-nofollow:
mailmap: do not respect symlinks for in-tree .mailmap
exclude: do not respect symlinks for in-tree .gitignore
attr: do not respect symlinks for in-tree .gitattributes
exclude: add flags parameter to add_patterns()
attr: convert "macro_ok" into a flags field
add open_nofollow() helper
Make CALLOC_ARRAY usable like a function by requiring callers to supply
the trailing semicolon, which all of the current ones already do. With
the extra semicolon e.g. the following code wouldn't compile because it
disconnects the "else" from the "if":
if (condition)
CALLOC_ARRAY(ptr, n);
else
whatever();
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Work around platforms whose open() is reported to return EINTR (it
shouldn't, as we do our signals with SA_RESTART).
* jk/open-returns-eintr:
config.mak.uname: enable OPEN_RETURNS_EINTR for macOS Big Sur
Makefile: add OPEN_RETURNS_EINTR knob
On some platforms, open() reportedly returns EINTR when opening regular
files and we receive a signal (usually SIGALRM from our progress meter).
This shouldn't happen, as open() should be a restartable syscall, and we
specify SA_RESTART when setting up the alarm handler. So it may actually
be a kernel or libc bug for this to happen. But it has been reported on
at least one version of Linux (on a network filesystem):
https://lore.kernel.org/git/c8061cce-71e4-17bd-a56a-a5fed93804da@neanderfunk.de/
as well as on macOS starting with Big Sur even on a regular filesystem.
We can work around it by retrying open() calls that get EINTR, just as
we do for read(), etc. Since we don't ever _want_ to interrupt an open()
call, we can get away with just redefining open, rather than insisting
all callsites use xopen().
We actually do have an xopen() wrapper already (and it even does this
retry, though there's no indication of it being an observed problem back
then; it seems simply to have been lifted from xread(), etc). But it is
used hardly anywhere, and isn't suitable for general use because it will
die() on error. In theory we could combine the two, but it's awkward to
do so because of the variable-args interface of open().
This patch adds a Makefile knob for enabling the workaround. It's not
enabled by default for any platforms in config.mak.uname yet, as we
don't have enough data to decide how common this is (I have not been
able to reproduce on either Linux or Big Sur myself). It may be worth
enabling preemptively anyway, since the cost is pretty low (if we don't
see an EINTR, it's just an extra conditional).
However, note that we must not enable this on Windows. It doesn't do
anything there, and the macro overrides the existing mingw_open()
redirection. I've added a preemptive #undef here in the mingw header
(which is processed first) to just quietly disable it (we could also
make it an #error, but there is little point in being so aggressive).
Reported-by: Aleksey Kliger <alklig@microsoft.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some callers of open() would like to use O_NOFOLLOW, but it is not
available on all platforms. Let's abstract this into a helper function
so we can provide system-specific implementations.
Some light web-searching reveals that we might be able to get something
similar on Windows using FILE_FLAG_OPEN_REPARSE_POINT. I didn't dig into
this further.
For other systems without O_NOFOLLOW or any equivalent, we have two
options for fallback:
- we can just open anyway, following symlinks; this may have security
implications (e.g., following untrusted in-tree symlinks)
- we can determine whether the path is a symlink with lstat().
This is slower (two syscalls instead of one), but that may be
acceptable for infrequent uses like looking up .gitattributes files
(especially because we can get away with a single syscall for the
common case of ENOENT).
It's also racy, but should be sufficient for our needs (we are
worried about in-tree symlinks that we ourselves would have
previously created). We could make it non-racy at the cost of making
it even slower, by doing an fstat() on the opened descriptor and
comparing the dev/ino fields to the original lstat().
This patch implements the lstat() option in its slightly-faster racy
form.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When commands are started from a subdirectory, they may have to
compare the path to the subdirectory (called prefix and found out
from $(pwd)) with the tracked paths. On macOS, $(pwd) and
readdir() yield decomposed path, while the tracked paths are
usually normalized to the precomposed form, causing mismatch. This
has been fixed by taking the same approach used to normalize the
command line arguments.
* tb/precompose-prefix-too:
MacOS: precompose_argv_prefix()
* maint-2.22:
Git 2.22.5
Git 2.21.4
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.21:
Git 2.21.4
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.20:
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.19:
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.18:
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.17:
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
Before checking out a file, we have to confirm that all of its leading
components are real existing directories. And to reduce the number of
lstat() calls in this process, we cache the last leading path known to
contain only directories. However, when a path collision occurs (e.g.
when checking out case-sensitive files in case-insensitive file
systems), a cached path might have its file type changed on disk,
leaving the cache on an invalid state. Normally, this doesn't bring
any bad consequences as we usually check out files in index order, and
therefore, by the time the cached path becomes outdated, we no longer
need it anyway (because all files in that directory would have already
been written).
But, there are some users of the checkout machinery that do not always
follow the index order. In particular: checkout-index writes the paths
in the same order that they appear on the CLI (or stdin); and the
delayed checkout feature -- used when a long-running filter process
replies with "status=delayed" -- postpones the checkout of some entries,
thus modifying the checkout order.
When we have to check out an out-of-order entry and the lstat() cache is
invalid (due to a previous path collision), checkout_entry() may end up
using the invalid data and thrusting that the leading components are
real directories when, in reality, they are not. In the best case
scenario, where the directory was replaced by a regular file, the user
will get an error: "fatal: unable to create file 'foo/bar': Not a
directory". But if the directory was replaced by a symlink, checkout
could actually end up following the symlink and writing the file at a
wrong place, even outside the repository. Since delayed checkout is
affected by this bug, it could be used by an attacker to write
arbitrary files during the clone of a maliciously crafted repository.
Some candidate solutions considered were to disable the lstat() cache
during unordered checkouts or sort the entries before passing them to
the checkout machinery. But both ideas include some performance penalty
and they don't future-proof the code against new unordered use cases.
Instead, we now manually reset the lstat cache whenever we successfully
remove a directory. Note: We are not even checking whether the directory
was the same as the lstat cache points to because we might face a
scenario where the paths refer to the same location but differ due to
case folding, precomposed UTF-8 issues, or the presence of `..`
components in the path. Two regression tests, with case-collisions and
utf8-collisions, are also added for both checkout-index and delayed
checkout.
Note: to make the previously mentioned clone attack unfeasible, it would
be sufficient to reset the lstat cache only after the remove_subtree()
call inside checkout_entry(). This is the place where we would remove a
directory whose path collides with the path of another entry that we are
currently trying to check out (possibly a symlink). However, in the
interest of a thorough fix that does not leave Git open to
similar-but-not-identical attack vectors, we decided to intercept
all `rmdir()` calls in one fell swoop.
This addresses CVE-2021-21300.
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
The following sequence leads to a "BUG" assertion running under MacOS:
DIR=git-test-restore-p
Adiarnfd=$(printf 'A\314\210')
DIRNAME=xx${Adiarnfd}yy
mkdir $DIR &&
cd $DIR &&
git init &&
mkdir $DIRNAME &&
cd $DIRNAME &&
echo "Initial" >file &&
git add file &&
echo "One more line" >>file &&
echo y | git restore -p .
Initialized empty Git repository in /tmp/git-test-restore-p/.git/
BUG: pathspec.c:495: error initializing pathspec_item
Cannot close git diff-index --cached --numstat
[snip]
The command `git restore` is run from a directory inside a Git repo.
Git needs to split the $CWD into 2 parts:
The path to the repo and "the rest", if any.
"The rest" becomes a "prefix" later used inside the pathspec code.
As an example, "/path/to/repo/dir-inside-repå" would determine
"/path/to/repo" as the root of the repo, the place where the
configuration file .git/config is found.
The rest becomes the prefix ("dir-inside-repå"), from where the
pathspec machinery expands the ".", more about this later.
If there is a decomposed form, (making the decomposing visible like this),
"dir-inside-rep°a" doesn't match "dir-inside-repå".
Git commands need to:
(a) read the configuration variable "core.precomposeunicode"
(b) precocompose argv[]
(c) precompose the prefix, if there was any
The first commit,
76759c7dff "git on Mac OS and precomposed unicode"
addressed (a) and (b).
The call to precompose_argv() was added into parse-options.c,
because that seemed to be a good place when the patch was written.
Commands that don't use parse-options need to do (a) and (b) themselfs.
The commands `diff-files`, `diff-index`, `diff-tree` and `diff`
learned (a) and (b) in
commit 90a78b83e0 "diff: run arguments through precompose_argv"
Branch names (or refs in general) using decomposed code points
resulting in decomposed file names had been fixed in
commit 8e712ef6fc "Honor core.precomposeUnicode in more places"
The bug report from above shows 2 things:
- more commands need to handle precomposed unicode
- (c) should be implemented for all commands using pathspecs
Solution:
precompose_argv() now handles the prefix (if needed), and is renamed into
precompose_argv_prefix().
Inside this function the config variable core.precomposeunicode is read
into the global variable precomposed_unicode, as before.
This reading is skipped if precomposed_unicode had been read before.
The original patch for preocomposed unicode, 76759c7dff, placed
precompose_argv() into parse-options.c
Now add it into git.c::run_builtin() as well. Existing precompose
calls in diff-files.c and others may become redundant, and if we
audit the callflows that reach these places to make sure that they
can never be reached without going through the new call added to
run_builtin(), we might be able to remove these existing ones.
But in this commit, we do not bother to do so and leave these
precompose callsites as they are. Because precompose() is
idempotent and can be called on an already precomposed string
safely, this is safer than removing existing calls without fully
vetting the callflows.
There is certainly room for cleanups - this change intends to be a bug fix.
Cleanups needs more tests in e.g. t/t3910-mac-os-precompose.sh, and should
be done in future commits.
[1] git-bugreport-2021-01-06-1209.txt (git can't deal with special characters)
[2] https://lore.kernel.org/git/A102844A-9501-4A86-854D-E3B387D378AA@icloud.com/
Reported-by: Daniel Troger <random_n0body@icloud.com>
Helped-By: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We allow variadic macros in the code base, but only if there is fallback
code for platforms that lack it. This leads to some annoyances:
- the code is more complicated because of the fallbacks (e.g.,
trace_printf(), etc, is implemented twice with a set of parallel
wrappers).
- some constructs are just impossible and we've had to live without
them (e.g., a cross between FLEX_ALLOC and xstrfmt)
Since this feature is present in C99, we may be able to start counting
on it being available everywhere. Let's start with a weather balloon
patch to find out.
This patch makes the absolute minimal change by always setting
HAVE_VARIADIC_MACROS. If somebody runs into a platform where it's a
problem, they can undo it by commenting out the define. Likewise, if we
have to revert this, it would be quite unlikely to cause conflicts.
Once we feel comfortable that this is the right direction, then we can
start ripping out all the spots that actually look at the flag, and
removing the dead code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 15b52a44 (compat-util: type-check parameters of no-op
replacement functions, 2020-08-06) turned a handful of no-op
C-preprocessor macros into static inline functions to give the
callers a better type checking for their parameters, it forgot
to return anything from the stubbed out setitimer() function,
even though the function was defined to return an int just like the
real thing.
Since the original C-preprocessor macro implementation was to just
turn the call to the function an empty statement, we know that the
existing callers do not check the return value from it, and it does
not matter what value we return. But it is safer to pretend that
the call succeeded by returning 0 than making it fail by returning -1
and clobbering errno with some value.
Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sleep function is defined in wrapper.c, so it makes more sense to be a in
system compatibility header.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The usage, die, warning, and error routines all work with a function
pointer that takes the message to be reported. We usually just mention
the function's full type inline. But this makes the use of these
pointers hard to read, especially because C's syntax for returning a
function pointer is so awful:
void (*get_error_routine(void))(const char *err, va_list params);
Unless you read it very carefully, this looks like a function pointer
declaration. Let's instead use a single typedef to define a reporting
function, which is the same for all four types.
Note that this also removes the "extern" from these declarations to
match the surrounding functions. They were missed in 554544276a (*.[ch]:
remove extern from function declarations using spatch, 2019-04-29)
presumably because of the unusual syntax.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>