Kernel builds, page refcounts, QUIC, and BPF hardening

Kernel development focused on build performance, lockless page reference counting, and native QUIC support, alongside security hardening in virtio-net and BPF. Multiple large patch series advanced scalability and memory-safety work across core subsystems.

kbuild claims major kernel build speedups

A 22-patch series posted as v4 to linux-kernel proposes kbuild changes that claim 36-90 percent faster kernel builds. The work covers toolchain caching, modpost and objtool modifications, parallel Rust and objtool execution, and pigz compression. Build-time improvements of this scale matter for anyone iterating on large kernel configurations.

Linus posts RCU page-refcount series

Linus Torvalds posted v3 of an RCU-based page-refcount series intended to enable lockless reads and improve scalability. Eight participants discussed races, f2fs edge cases, and large-folio performance. The series targets concurrent page reference counting under heavy load.

Kernel QUIC infrastructure reaches v17

A 15-patch series for net-next introduces QUIC infrastructure and core subcomponents, covering sockets, crypto, paths, congestion control, and packet handling. The posting continues a long-running effort to bring the transport protocol into the mainline networking stack. Native kernel QUIC support would reduce reliance on userspace implementations for compatible applications.

virtio-net checksum hardening

A seven-patch v2 series hardens virtio-net partial checksum validation at ingress. The changes aim to block untrusted device packet edits that could produce inconsistent views inside the network stack. Six participants discussed the security-oriented work on linux-kernel.

RFC for stealable FUTEX_PING locks

A 12-patch RFC proposes FUTEX_PING, adding stealable priority-inheritance locks via proxy execution. Discussion among six participants, including Zijlstra, raised deadlock and locking-order concerns. The design explores alternative futex behavior for contended locking patterns.

O_CREAT|O_DIRECTORY open semantics

Version 7 of a 12-patch series adds O_CREAT|O_DIRECTORY support to open*(2) for atomic mkdir-plus-open with a pinning file descriptor, plus related namei and kernfs changes. The work was posted to linux-kernel by two participants. Callers that need atomic directory creation and open would gain a simpler, race-free interface.

BPF verifier memory-safety fixes

A 38-patch series for bpf-next addresses multiple memory-safety, lifetime, and locking bugs in the BPF verifier and maps. Three participants exchanged 51 messages on the changes. The volume of fixes continues hardening of a subsystem that runs untrusted programs in kernel context.

BPF callback argument lifetime scoping

Version 2 of an 11-patch series introduces REF_TYPE_FRAME to bind callback arguments to callee lifetime. The change closes kernel read and write plus stack-leak issues in ringbuf and arraymap helpers. Posted to bpf-next, the work tightens verifier guarantees around helper callbacks.