Tetragon, the BPF-based security monitoring tool, uses BPF to monitor different aspects of a running kernel and enforce user-specified policies. It sends its data to a user-space process, which forwards the data to a central monitoring service elsewhere in the network, however. This presents a point of vulnerability: if an attacker can kill Tetragon's user-space agent, it won't be able to properly report on the situation. Song Liu, Mahé Tardy, and Liam Wiseheart spoke about their work removing the need for the user-space agent at the 2026 Linux Storage, Filesystem, Memory-Management, and BPF Summit.

Cisco has some unusual challenges when it comes to deploying security patches across the company's many devices running custom kernels. John Fastabend spoke about his work preventing exploits with BPF at the 2026 Linux Storage, Filesystem, Memory-Management, and BPF Summit. The technique could substantially reduce the time necessary to respond to kernel vulnerabilities, but it will not be fully effective unless more hooks are added to the kernel.

Debian has announced the final normal update for Debian 12 ("bookworm"). Long-term-support updates will continue until 2028. As may be expected from a stable version, the update is mostly limited to security fixes. Still, it may be time for Debian users to look into upgrading to a more recent version. Conveniently, Debian 13 ("trixie") also received an update this weekend, with many of the same security fixes.

QBE, a compact compiler backend developed by Quentin Carbonneaux, is a lightweight alternative to larger compiler backends such as LLVM and GCC. Designed to be small enough for a single developer to understand, QBE uses a static single-assignment (SSA) intermediate representation (IR), supports the C ABI, and serves as the backend for projects such as Hare and the cproc C11 compiler. Frontends emit the textual form of QBE's IR directly; QBE then takes care of register allocation, optimization, and native-code generation, producing assembly for the target architecture.

Puranjay Mohan shared some of the work he's been doing recently on improving the performance of read-copy-update (RCU) at the 2026 Linux Storage, Filesystem, Memory-Management, and BPF Summit; his talk would have been nice context to have earlier in the day when Harry Yoo and Alexei Starovoitov led a session about the new kmalloc_nolock() function that allows for lockless allocation from any kernel context, and which interacts with the RCU subsystem to allow that. This article therefore covers the two sessions together and in the reverse order, to provide that missing context.

When a BPF program is used to filter or redirect packets in the networking subsystem, the program will often want to associate data with each packet as it moves through the kernel. The kernel's local BPF storage API, which associates extra data with some kernel objects, provides a way to do that. (See also the BPF map types that end in STORAGE.) Amery Hung and Jakub Sitnicki led two sessions at the 2026 Linux Storage, Filesystem, Memory-Management, and BPF Summit about how to make accesses to local storage data more efficient. Hung spoke about general performance problems related to locking, while Sitnicki examined the use of local storage in the networking subsystem in particular.

Lisp-like languages have historically led the world in metaprogramming and flexibility. While many modern languages have adopted the idea of macros, Lisp-like languages such as Racket have continued pushing the envelope, attempting to make macros as easy as possible to incorporate into everyday programs. On the other hand, Lisp's minimal, parenthesis-based syntax can be hard to adapt to — to the point that Lisp is sometimes said to stand for "Lots of Irritating Silly Parentheses". Rhombus is a new programming language that aims to have the best of both worlds, marrying Racket's metaprogramming capabilities to a simple Python-like syntax and reasonable standard-library defaults.