Jakub Kicinski aba53ccf05 Merge tag 'nf-26-04-01' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net. Note that most
of the bugs fixed here are >5 years old.  The large PR is not due to an
increase in regressions.

1) Flowtable hardware offload support in IPv6 can lead to out-of-bounds
   when populating the rule action array when combined with double-tagged
   vlan. Bump the maximum number of actions from 16 to 24 and check that
   such limit is never reached, otherwise bail out.  This bugs stems from
   the original flowtable hardware offload support.

2) nfnetlink_log does not include the netlink header size of the trailing
   NLMSG_DONE message when calculating the skb size. From Florian Westphal.

3) Reject names in xt_cgroup and xt_rateest extensions which are not
   nul-terminated. Also from Florian.

4) Use nla_strcmp in ipset lookup by set name, since IPSET_ATTR_NAME and
   IPSET_ATTR_NAMEREF are of NLA_STRING type. From Florian Westphal.

5) When unregistering conntrack helpers, pass the helper that is going
   away so the expectation cleanup is done accordingly, otherwise UaF is
   possible when accessing expectation that refer to the helper that is
   gone. From Qi Tang.

6) Zero expectation NAT fields to address leaking kernel memory through
   the expectation netlink dump when unset. Also from Qi Tang.

7) Use the master conntrack helper when creating expectations via
   ctnetlink, ignore the suggested helper through CTA_EXPECT_HELP_NAME.
   This allows to address a possible read of kernel memory off the
   expectation object boundary.

8) Fix incorrect release of the hash bucket logic in ipset when the
   bucket is empty, leading to shrinking the hash bucket to size 0
   which deals to out-of-bound write in next element additions.
   From Yifan Wu.

9) Allow the use of x_tables extensions that explicitly declare
   NFPROTO_ARP support only. This is to avoid an incorrect hook number
   validation due to non-overlapping arp and inet hook number
   definitions.

10) Reject immediate NF_QUEUE verdict in nf_tables. The userspace
    nft tool always uses the nft_queue expression for queueing.
    This ensures this verdict cannot be used for the arp family,
    which does supported this.

* tag 'nf-26-04-01' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: reject immediate NF_QUEUE verdict
  netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP
  netfilter: ipset: drop logically empty buckets in mtype_del
  netfilter: ctnetlink: ignore explicit helper on new expectations
  netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absent
  netfilter: nf_conntrack_helper: pass helper to expect cleanup
  netfilter: ipset: use nla_strcmp for IPSET_ATTR_NAME attr
  netfilter: x_tables: ensure names are nul-terminated
  netfilter: nfnetlink_log: account for netlink header size
  netfilter: flowtable: strictly check for maximum number of actions
====================

Link: https://patch.msgid.link/20260401103646.1015423-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-01 19:19:36 -07:00
2026-01-26 19:07:09 -08:00
2022-09-28 09:02:20 +02:00
2025-02-19 14:53:27 -07:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros
* AI Coding Assistant - LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
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* MAINTAINERS file: Lists subsystem maintainers and mailing lists
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