The 6.8.7, 6.6.28, 6.1.87, and 5.15.156 stable kernel updates have all been released.

The recent XZ backdoor has sparked a lot of discussion about how the open-source community links and packages software. One possible security improvement being discussed is changing how projects like systemd link to dynamic libraries that are only used for optional functionality: using dlopen() to load those libraries only when required. This could shrink the attack surface exposed by dependencies, but the approach is not without downsides — most prominently, it makes discovering which dynamic libraries a program depends on harder. On April 11, Lennart Poettering proposed one way to eliminate that problem in a systemd RFC on GitHub.

Fedora 40 Beta was released on March 26, and the final release is nearing completion. So far, the release is coming together nicely with major updates for GNOME, KDE Plasma, and the usual cavalcade of smaller updates and enhancements. As part of the release, the project also scuttled Delta RPMs and OpenSSL 1.1.

PuTTY 0.81, released today, fixes a critical vulnerability CVE-2024-31497 in the use of 521-bit ECDSA keys (ecdsa-sha2-nistp521). If you have used a 521-bit ECDSA private key with any previous version of PuTTY, consider the private key compromised: remove the public key from authorized_keys files, and generate a new key pair.

However, this only affects that one algorithm and key size. No other size of ECDSA key is affected, and no other key type is affected.

(Thanks to Joe Nahmias).

The OpenJS Foundation Cross Project Council received a suspicious series of emails with similar messages, bearing different names and overlapping GitHub-associated emails. These emails implored OpenJS to take action to update one of its popular JavaScript projects to "address any critical vulnerabilities," yet cited no specifics. The email author(s) wanted OpenJS to designate them as a new maintainer of the project despite having little prior involvement.

Kumar Kartikeya Dwivedi has been working to add support for exceptions to BPF since mid-2023. In July, Dwivedi posted the first patch set in this effort, which adds support for basic stack unwinding. In February 2024, he posted the second patch set aimed at letting the kernel release resources held by the BPF program when an exception occurs. This makes exceptions usable in many more contexts.

Debian, as well as the other affected distributions like openSUSE are carrying a significant amount of downstream-only patches to essential open-source projects, like in this case OpenSSH. With hindsight, that should be another Heartbleed-level learning for the work of the distributions. These patches built the essential steps to embed the backdoor, and do not have the scrutiny that they likely would have received by the respective upstream maintainers. Whether you trust Linus Law or not, it was not even given a chance to chime in here. Upstream did not fail on the users, distributions failed on upstream and their users here.