Linux kernel source tree
Go to file
Linus Torvalds b040da2a00 signal: use scoped user access in __save_altstack()
__save_altstack() and __compat_save_altstack() write three fields with
__put_user(), relying on the caller having done access_ok() on the whole
signal frame.  Each of those writes enables and disables user access on
its own, so that check saves nothing.

x86 and powerpc already avoid these functions by using
unsafe_save_altstack() inside their own user access regions.  Use the
same helpers here, inside a scoped_user_write_access(), so that every
other architecture gets a single range check and a single user access
region too.  None of those callers is itself inside a user access
region, so nothing nests.

This is part of getting rid of __get_user() and __put_user() entirely.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-10-19 19:23:16 -10:00
arch x86/core update: 2026-10-18 07:48:22 -10:00
block SCSI fixes on 20261018 2026-10-18 09:06:02 -10:00
certs treewide: fix indentation and whitespace in Kconfig files 2026-05-28 21:24:42 -07:00
crypto crypto: aes - Fix undesired override of some optimized AES modes 2026-09-30 08:38:06 -07:00
Documentation spi: Fixes for v7.3 2026-10-11 11:33:26 -07:00
drivers SCSI fixes on 20261018 2026-10-18 09:06:02 -10:00
fs Revert "namei: don't reveal overmounted entries in refwalk" 2026-10-16 10:50:57 +02:00
include SCSI fixes on 20261018 2026-10-18 09:06:02 -10:00
init Random number generator fixes for Linux 7.3-rc6. 2026-10-02 11:28:45 -07:00
io_uring io_uring-7.3-20261010 2026-10-11 08:53:11 -07:00
ipc ipc: drop the mqueue mount with kern_unmount() on setup failure 2026-10-14 22:08:03 +02:00
kernel signal: use scoped user access in __save_altstack() 2026-10-19 19:23:16 -10:00
lib Crypto library fixes for 7.3-final 2026-10-14 08:23:37 -07:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm mm: don't schedule deferred kernel page table freeing while booting 2026-10-06 16:44:18 -07:00
net net/sched: fix use-after-free in __tcf_action_put() 2026-10-15 13:00:02 +02:00
rust rust: net: netlink: validate attribute length before casting to c_int 2026-09-29 12:28:03 +02:00
samples samples: pidfd: fix userprogs typo 2026-10-14 22:08:01 +02:00
scripts hid-for-linus-2026092202 2026-09-22 10:30:17 -07:00
security Landlock fix for v7.3-rc7 2026-10-11 11:49:08 -07:00
sound ASoC: amd: yc: disable MSI on resume 2026-10-13 14:32:22 +01:00
tools x86/insn-eval: Fix shadowed segment index in get_seg_reg_override_idx() 2026-10-17 06:36:20 -10:00
usr usr: Correct a spelling by changing a letter 2026-08-05 14:51:58 +02:00
virt KVM: WARN if vCPU creation is in-progress when locking all vCPUs 2026-09-26 00:49:49 -04:00
.clang-format drm/bridge: rename drm_for_each_bridge_in_chain_scoped() to drm_for_each_bridge_in_chain() 2026-07-14 17:55:51 +02:00
.clippy.toml rust: bump Clippy's MSRV and clean incompatible_msrv allows 2026-04-07 09:51:39 +02:00
.cocciconfig
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore .get_maintainer.ignore: add myself 2026-09-07 10:01:33 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore SPDX patches for 7.2-rc1 2026-06-22 12:06:22 -07:00
.mailmap 7 hotfixes. 4 are cc:stable. 2026-10-08 12:35:20 +02:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml
COPYING
CREDITS Driver core fixes for 7.3-rc2 2026-09-05 11:59:05 -07:00
Kbuild checksyscalls: move instance functionality into generic code 2026-04-05 09:21:32 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS drm fixes for 7.3 final 2026-10-16 15:33:36 -10:00
Makefile Linux 7.3 2026-10-18 13:14:58 -10:00
README README: remove out of place emdashes 2026-07-15 10:51:29 -06:00

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