Kernel mm fixes, BPF work, and security hardening

Kernel traffic centered on large memory-management and BPF patch series, alongside security fixes for KVM, zswap, and RDMA. Scheduler steal-governor work landed in tip while a USB pull drew complaints over boot log noise.

46-patch mm fixes series

David Hildenbrand submitted a 46-patch series of memory-management fixes that generated 201 messages of review. Discussion concentrated on races and hugepage handling. The volume and urgency framing make the series relevant to anyone tracking core mm stability.

BPF deferred instruction patches

A 22-patch bpf-next series replaces immediate bpf_patch_insn_data() calls with a sorted list of deferred patches. The change removes O(N*M) work from the verifier. It improves scalability for complex BPF programs under review.

BPF user-memory kfuncs

Jiri Olsa posted an initial eight-patch series adding sleepable kfuncs for user-memory mmap, munmap, and fault-aware copy_to_user. Reviewers examined const inference and architecture protection checks. The interface expands safe BPF interaction with process memory.

Steal governor preferred-CPU series merged

Version 14 of the steal_governor series, adding preferred CPUs and steal-driven vCPU backoff, was merged into tip/sched/core. The patches adjust scheduler behavior for virtualized workloads. Guests and hosts that track steal time gain more controlled backoff.

KVM dying-VM uaccess hardening

The KVM maintainer released a 23-patch v4 series that fixes and hardens against bad uaccess during nested VMX teardown. A dying VM could previously corrupt unrelated process memory. The changes close a host-side corruption path.

zswap stale-data and swap-in fixes

A three-patch series corrects stale zswap data retention and a swap-in extent bug. On zram or synchronous devices the bug could expose data belonging to other users. The fixes close a cross-user information leak in the swap path.

RDMA/rxe send-path TOCTOU fix

Version 8 of an RDMA/rxe series copies send work-queue entries into kernel buffers before processing. The change eliminates TOCTOU races previously identified in the soft RoCE target. It hardens the send path against concurrent user modification.

USB pull log-spam dispute

Linus Torvalds objected to excessive boot-log spam introduced by a UCSI retry commit inside the USB/Thunderbolt updates for 7.4-rc1. A developer replied with a targeted fix. The exchange shows how logging volume can block otherwise routine driver merges.