Kernel security fixes and BPF infrastructure work

Stable kernel trees received backports for a netfilter use-after-free, while BPF and networking series advanced exception cleanup, BTF memory savings, and IPsec correctness. KVM uaccess hardening and ext4 buffered I/O conversion also moved forward.

Stable backports for nf_tables netdev UAF

A use-after-free in nf_tables_netdev_event binding-chain handling has been fixed and requested for stable backports to 6.12, 6.6, and 6.1. The patches were tested and posted to the stable list so affected long-term kernels can pick up the correction. Readers who ship or run those stables should track the series for the security impact on netfilter.

BPF exception cleanup landing pads for unwind

A 22-patch v8 series on bpf-next implements exception cleanup landing pads that run when bpf_unwind() unwinds frames. The work enables Drop-style resource release across frames and is aimed at Rust BPF use cases. It matters for safe resource handling when BPF programs unwind through multiple frames.

On-demand vmlinux BTF module to cut memory

A nine-patch v3 series makes CONFIG_DEBUG_INFO_BTF tristate so the vmlinux BTF image can ship as an on-demand loadable module. Unused systems save about 5.4 MB of memory. Deployments that do not need BTF at boot can reclaim that footprint without losing the option to load it later.

xfrm ESP IV generation and ESN authentication fixes

A seven-patch series corrects AES-GCM nonce reuse and ESN sequence bugs in the Linux xfrm/ESP IPv4 and IPv6 offload paths. The changes close correctness and security gaps in IPsec offload. Operators relying on kernel ESP should review the series for exposure to IV reuse or authentication failures.

KVM hardening of uaccess on dying VMs

Sean Christopherson posted a v2 ten-patch set that fixes and hardens KVM against bad uaccess while a VM is being torn down. The goal is to prevent memory corruption of unrelated processes during teardown. Hosts running untrusted or short-lived VMs gain protection against this class of fault.

ext4 buffered I/O path conversion to iomap

A 31-patch v6 series continues converting ext4 regular-file buffered I/O from buffer_head to iomap. It addresses ordering, i_disksize, and data=ordered issues along the way. The change modernizes the I/O path and reduces long-standing buffer_head dependencies for ext4 users.

BPF-based MIPI-DSI panel driver proposal

Maxime Ripard proposed a six-patch BPF-based MIPI-DSI panel driver in the style of HID-BPF, allowing runtime-loaded init sequences. Maintainers debated device-tree bindings and overall design across a long thread. The approach could simplify panel bring-up without baking sequences into the kernel image.

NUMA balancing promotion past VMA scan filters

A seven-patch v4 set stops VMA scan filters from gating promotion under NUMA balancing. Production gains on CXL and DAM configurations were reported. Workloads that benefit from aggressive page promotion on heterogeneous memory can see improved balancing behavior.