Linus Torvalds fa58e6e900 Merge tag 'io_uring-7.1-20260424' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring fixes from Jens Axboe:

 - Fix for a NOMMU bug with io_uring, where NOMMU doesn't grab page refs
   at mmap time. NOMMU also has entirely broken FOLL_PIN support, yet
   here we are

 - A few fixes covering minor issues introduced in this merge window

 - data race annotation to shut up KCSAN for when io-wq limits are
   applied

 - A nospec addition for direct descriptor file updating. Rest of the
   direct descriptor path already had this, but for some reason the
   update did not. Now they are all the same

 - Various minor defensive changes that claude identified and suggested
   terrible fixes for, turned into actually useful cleanups:

       - Use kvfree() for the imu cache. These can come from kmalloc or
         vmalloc depending on size, but the in-cache ones are capped
         where it's always kmalloc based. Change to kvfree() in the
         cleanup path, making future changes unlikely to mess that up

       - Negative kbuf consumption lengths. Can't happen right now, but
         cqe->res is used directly, which if other codes changes could
         then be an error value

 - Fix for an issue with the futex code, where partial wakes on a
   vectored fuxes would potentially wake the same futex twice, rather
   than move on to the next one. This could confuse an application as it
   would've expected the next futex to have been woken

 - Fix for a bug with ring resizing, where SQEs or CQEs might not have
   been copied correctly if large SQEs or CQEs are used in the ring.
   Application side issue, where SQEs or CQEs might have been lost
   during resize

 - Fix for a bug where EPOLL_URING_WAKE might have been lost, causing a
   multishot poll to not be terminated when it's nested, like it should
   have been

 - Fix for an issue with signed comparison of poll references for the
   slow path

 - Fix for a user struct UAF in the zcrx code

 - Two minor zcrx cleanups

* tag 'io_uring-7.1-20260424' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: take page references for NOMMU pbuf_ring mmaps
  io_uring/poll: ensure EPOLL_ONESHOT is propagated for EPOLL_URING_WAKE
  io_uring/zcrx: warn on freelist violations
  io_uring/zcrx: clear RQ headers on init
  io_uring/zcrx: fix user_struct uaf
  io_uring/register: fix ring resizing with mixed/large SQEs/CQEs
  io_uring/futex: ensure partial wakes are appropriately dequeued
  io_uring/rw: add defensive hardening for negative kbuf lengths
  io_uring/rsrc: use kvfree() for the imu cache
  io_uring/rsrc: unify nospec indexing for direct descriptors
  io_uring: fix spurious fput in registered ring path
  io_uring: fix iowq_limits data race in tctx node addition
  io_uring/tctx: mark io_wq as exiting before error path teardown
  io_uring/tctx: check for setup tctx->io_wq before teardown
  io_uring/poll: fix signed comparison in io_poll_get_ownership()
2026-04-24 15:00:54 -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
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst
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