7d7efce1d9
This avoids needing to always serialise a variant before byteswapping it. With variants in non-normal forms, serialisation can result in a large increase in size of the variant, and a lot of allocations for leaf `GVariant`s. This can lead to a denial of service attack. Avoid that by changing byteswapping so that it happens on the tree form of the variant if the input is in non-normal form. If the input is in normal form (either serialised or in tree form), continue using the existing code as byteswapping an already-serialised normal variant is about 3× faster than byteswapping on the equivalent tree form. The existing unit tests cover byteswapping well, but need some adaptation so that they operate on tree form variants too. I considered dropping the serialised byteswapping code and doing all byteswapping on tree-form variants, as that would make maintenance simpler (avoiding having two parallel implementations of byteswapping). However, most inputs to `g_variant_byteswap()` are likely to be serialised variants (coming from a byte array of input from some foreign source) and most of them are going to be in normal form (as corruption and malicious action are rare). So getting rid of the serialised byteswapping code would impose quite a performance penalty on the common case. Signed-off-by: Philip Withnall <pwithnall@endlessos.org> Fixes: #2797
GLib
GLib is the low-level core library that forms the basis for projects such as GTK and GNOME. It provides data structure handling for C, portability wrappers, and interfaces for such runtime functionality as an event loop, threads, dynamic loading, and an object system.
The official download locations are: https://download.gnome.org/sources/glib
The official web site is: https://www.gtk.org/
Installation
See the file 'INSTALL.md'
Supported versions
Only the most recent unstable and stable release series are supported. All older versions are not supported upstream and may contain bugs, some of which may be exploitable security vulnerabilities.
See SECURITY.md for more details.
Documentation
API documentation is available online for GLib for the:
Discussion
If you have a question about how to use GLib, seek help on GNOME’s Discourse
instance. Alternatively, ask a question
on StackOverflow and tag it glib.
Reporting bugs
Bugs should be reported to the GNOME issue tracking system. You will need to create an account for yourself. You may also submit bugs by e-mail (without an account) by e-mailing incoming+gnome-glib-658-issue-@gitlab.gnome.org, but this will give you a degraded experience.
Bugs are for reporting problems in GLib itself, not for asking questions about how to use it. To ask questions, use one of our discussion forums.
In bug reports please include:
- Information about your system. For instance:
- What operating system and version
- For Linux, what version of the C library
- And anything else you think is relevant.
- How to reproduce the bug.
- If you can reproduce it with one of the test programs that are built
in the
tests/subdirectory, that will be most convenient. Otherwise, please include a short test program that exhibits the behavior. As a last resort, you can also provide a pointer to a larger piece of software that can be downloaded.
- If you can reproduce it with one of the test programs that are built
in the
- If the bug was a crash, the exact text that was printed out when the crash occurred.
- Further information such as stack traces may be useful, but is not necessary.
Contributing to GLib
Please follow the contribution guide to know how to start contributing to GLib.
Patches should be submitted as merge requests to gitlab.gnome.org. If the patch fixes an existing issue, please refer to the issue in your commit message with the following notation (for issue 123):
Closes: #123
Otherwise, create a new merge request that introduces the change. Filing a separate issue is not required.
Default branch renamed to main
The default development branch of GLib has been renamed to main. To update
your local checkout, use:
git checkout master
git branch -m master main
git fetch
git branch --unset-upstream
git branch -u origin/main
git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main