Ensure key CMake option values are part of the CMake output to
facilitate user support when tool updates impact the wider CMake
actions, particularly ongoing 'improvements' in Visual Studio.
These CMake displays perform the same function as the build-options.txt
provided in the main Git for Windows. CMake is already chatty.
The setting of CMAKE_EXPORT_COMPILE_COMMANDS is also reported.
Include the environment's CMAKE_EXPORT_COMPILE_COMMANDS value which
may have been propogated to CMake's internal value.
Testing the CMAKE_EXPORT_COMPILE_COMMANDS processing can be difficult
in the Visual Studio environment, as it may be cached in many places.
The 'environment' may include the OS, the user shell, CMake's
own environment, along with the Visual Studio presets and caches.
See previous commit for arefacts that need removing for a clean test.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
In Git-for-Windows, work on using ARM64 has progressed. The
commit 2d94b77b27 (cmake: allow building for Windows/ARM64, 2020-12-04)
failed to notice that /compat/vcbuild/vcpkg_install.bat will default to
using the "x64-windows" architecture for the vcpkg installation if not set,
but CMake is not told of this default. Commit 635b6d99b3 (vcbuild: install
ARM64 dependencies when building ARM64 binaries, 2020-01-31) later updated
vcpkg_install.bat to accept an arch (%1) parameter, but retained the default.
This default is neccessary for the use case where the project directory is
opened directly in Visual Studio, which will find and build a CMakeLists.txt
file without any parameters, thus expecting use of the default setting.
Also Visual studio will generate internal .sln solution and .vcxproj project
files needed for some extension tools. Inform users of the additional
.sln/.vcxproj generation.
** How to test:
rm -rf '.vs' # remove old visual studio settings
rm -rf 'compat/vcbuild/vcpkg' # remove any vcpkg downloads
rm -rf 'contrib/buildsystems/out' # remove builds & CMake artifacts
with a fresh Visual Studio Community Edition, File>>Open>>(git *folder*)
to load the project (which will take some time!).
check for successful compilation.
The implicit .sln (etc.) are in the hidden .vs directory created by
Visual Studio.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
The CMakeSettings.json file is tool generated. Developers may track it
should they provide additional settings.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
Git's regular Makefile mentions that HOST_CPU should be defined when cross-compiling Git: 37796bca76/Makefile (L438-L439)
This is then used to set the GIT_HOST_CPU variable when compiling Git: 37796bca76/Makefile (L1337-L1341)
Then, when the user runs `git version --build-options`, it returns that value: 37796bca76/help.c (L658)
This commit adds the same functionality to the CMake configuration. Users can now set -DHOST_CPU= to set the target architecture.
Signed-off-by: Dennis Ameling <dennis@dennisameling.com>
There are no Windows/ARM64 agents in GitHub Actions yet, therefore we
just skip adjusting the `vs-test` job for now.
Signed-off-by: Dennis Ameling <dennis@dennisameling.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In this context, a "feature" is a dependency combined with its own
dependencies.
Signed-off-by: Ian Bearman <ianb@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The vcpkg downloads may not succeed. Warn careful readers of the time out.
A simple retry will usually resolve the issue.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The vcpkg_install batch file depends on the availability of a
working Git on the CMD path. This may not be present if the user
has selected the 'bash only' option during Git-for-Windows install.
Detect and tell the user about their lack of a working Git in the CMD
window.
Fixes#2348.
A separate PR https://github.com/git-for-windows/build-extra/pull/258
now highlights the recommended path setting during install.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
This topic branch extends the protections introduced for Git GUI's
CVE-2022-41953 to cover `gitk`, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This topic branch fixes a vulnerability in Git GUI's "clone" feature
(tracked as CVE-2022-41953) that was graded with a CVSS Score 8.6/10
(high).
These patches were backported to Git GUI in
https://github.com/prati0100/git-gui/pull/85
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Just like CVE-2022-41953 for Git GUI, there exists a vulnerability of
`gitk` where it looks for `taskkill.exe` in the current directory before
searching `PATH`.
Note that the many `exec git` calls are unaffected, due to an obscure
quirk in Tcl's `exec` function. Typically, `git.exe` lives next to
`wish.exe` (i.e. the program that is run to execute `gitk` or Git GUI)
in Git for Windows, and that is the saving grace for `git.exe because
`exec` searches the directory where `wish.exe` lives even before the
current directory, according to
https://www.tcl-lang.org/man/tcl/TclCmd/exec.htm#M24:
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 same is not true, however, for `taskkill.exe`: it lives in the
Windows system directory (never mind the 32-bit, Tcl's documentation is
outdated on that point, it really means `C:\Windows\system32`).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
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>
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>
We need these in `_which` and they should be defined before that
function's definition.
This commit is best viewed with `--color-moved`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
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>
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:
https://github.com/git-for-windows/MINGW-packages/commit/82172388bb51
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-L135https://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>
* maint-2.39: (34 commits)
Git 2.39.3
Git 2.38.5
Git 2.37.7
Git 2.36.6
Git 2.35.8
Makefile: force -O0 when compiling with SANITIZE=leak
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
range-diff: use ssize_t for parsed "len" in read_patches()
...
* maint-2.38: (32 commits)
Git 2.38.5
Git 2.37.7
Git 2.36.6
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
...
* maint-2.37: (31 commits)
Git 2.37.7
Git 2.36.6
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
...
* maint-2.36: (30 commits)
Git 2.36.6
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
...
* maint-2.35: (29 commits)
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
...
* maint-2.34: (28 commits)
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
...
* maint-2.33: (27 commits)
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
...
* maint-2.32: (26 commits)
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
ci: install python on ubuntu
...
* maint-2.31: (25 commits)
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
ci: install python on ubuntu
ci: use the same version of p4 on both Linux and macOS
...
Since `test_i18ncmp` was deprecated in v2.31.*, the instances added in
v2.30.9 needed to be converted to `test_cmp` calls.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
* maint-2.30: (23 commits)
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
ci: install python on ubuntu
ci: use the same version of p4 on both Linux and macOS
ci: remove the pipe after "p4 -V" to catch errors
github-actions: run gcc-8 on ubuntu-20.04 image
...
Avoids issues with renaming or deleting sections with long lines, where
configuration values may be interpreted as sections, leading to
configuration injection. Addresses CVE-2023-29007.
* tb/config-copy-or-rename-in-file-injection:
config.c: disallow overly-long lines in `copy_or_rename_section_in_file()`
config.c: avoid integer truncation in `copy_or_rename_section_in_file()`
config: avoid fixed-sized buffer when renaming/deleting a section
t1300: demonstrate failure when renaming sections with long lines
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Avoids the overhead of calling `gettext` when initialization of the
translated messages was skipped. Addresses CVE-2023-25815.
* avoid-using-uninitialized-gettext: (1 commit)
gettext: avoid using gettext if the locale dir is not present
Address CVE-2023-25652 by deleting any existing `.rej` symbolic links
instead of following them.
* js/apply-overwrite-rej-symlink-if-exists:
apply --reject: overwrite existing `.rej` symlink if it exists
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
As a defense-in-depth measure to guard against any potentially-unknown
buffer overflows in `copy_or_rename_section_in_file()`, refuse to work
with overly-long lines in a gitconfig.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
There are a couple of spots within `copy_or_rename_section_in_file()`
that incorrectly use an `int` to track an offset within a string, which
may truncate or wrap around to a negative value.
Historically it was impossible to have a line longer than 1024 bytes
anyway, since we used fgets() with a fixed-size buffer of exactly that
length. But the recent change to use a strbuf permits us to read lines
of arbitrary length, so it's possible for a malicious input to cause us
to overflow past INT_MAX and do an out-of-bounds array read.
Practically speaking, however, this should never happen, since it
requires 2GB section names or values, which are unrealistic in
non-malicious circumstances.
Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
When renaming (or deleting) a section of configuration, Git uses the
function `git_config_copy_or_rename_section_in_file()` to rewrite the
configuration file after applying the rename or deletion to the given
section.
To do this, Git repeatedly calls `fgets()` to read the existing
configuration data into a fixed size buffer.
When the configuration value under `old_name` exceeds the size of the
buffer, we will call `fgets()` an additional time even if there is no
newline in the configuration file, since our read length is capped at
`sizeof(buf)`.
If the first character of the buffer (after zero or more characters
satisfying `isspace()`) is a '[', Git will incorrectly treat it as
beginning a new section when the original section is being removed. In
other words, a configuration value satisfying this criteria can
incorrectly be considered as a new secftion instead of a variable in the
original section.
Avoid this issue by using a variable-width buffer in the form of a
strbuf rather than a fixed-with region on the stack. A couple of small
points worth noting:
- Using a strbuf will cause us to allocate arbitrary sizes to match
the length of each line. In practice, we don't expect any
reasonable configuration files to have lines that long, and a
bandaid will be introduced in a later patch to ensure that this is
the case.
- We are using strbuf_getwholeline() here instead of strbuf_getline()
in order to match `fgets()`'s behavior of leaving the trailing LF
character on the buffer (as well as a trailing NUL).
This could be changed later, but using strbuf_getwholeline() changes
the least about this function's implementation, so it is picked as
the safest path.
- It is temping to want to replace the loop to skip over characters
matching isspace() at the beginning of the buffer with a convenience
function like `strbuf_ltrim()`. But this is the wrong approach for a
couple of reasons:
First, it involves a potentially large and expensive `memmove()`
which we would like to avoid. Second, and more importantly, we also
*do* want to preserve those spaces to avoid changing the output of
other sections.
In all, this patch is a minimal replacement of the fixed-width buffer in
`git_config_copy_or_rename_section_in_file()` to instead use a `struct
strbuf`.
Reported-by: André Baptista <andre@ethiack.com>
Reported-by: Vítor Pinho <vitor@ethiack.com>
Helped-by: Patrick Steinhardt <ps@pks.im>
Co-authored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
