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Jakub Kicinski fe9f4ee6c6 Merge branch 'net-avoid-nested-up-notifier-events'
Jakub Kicinski says:

====================
net: avoid nested UP notifier events

syzbot reported that recent ethtool rework leads to deadlock
on stacked devices. VLANs create nested notifications, confusing
execution context. Bringing up dummy causes vlan to bring itself
up as well. Which in turn causes bond to ask for link state -
a call chain traveling in the opposite direction.

  bond    (3) bond_update_speed_duplex(vlan)
    |           ^                v
  vlan    (2) UP(vlan)    (4) vlan_ethtool_get_link_ksettings()
    |           ^                v
  dummy   (1) UP(dummy)   (5) __ethtool_get_link_ksettings()

We locked the instance lock of dummy at (1) and will will
try to lock it again at (5) - which of course deadlocks.

For non-nested notifications this is avoided because NETDEV_UP
is always run ops-locked (so that bond asks for link using the
netif_ API which assumes instance lock already held). The nesting,
however, makes this problematic, we cannot carry the state of
the whole chain back in the opposite direction.

AFAICT vlan is the only driver which causes such issues.
So let's try a localized fix of deferring vlan auto-open
to a workqueue.
====================

Link: https://patch.msgid.link/20260624182018.2445732-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25 10:18:41 -07:00
arch Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
block - small cleanups in dm-vdo, dm-raid, dm-cache, dm-zoned-metadata 2026-06-16 13:20:54 +05:30
certs Clang build fixes for 7.1 2026-04-24 09:29:51 -07:00
crypto Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
Documentation vlan: defer real device state propagation to netdev_work 2026-06-25 10:18:40 -07:00
drivers net: ethtool: keep rtnl_lock for ops using ethtool_op_get_link() 2026-06-25 10:18:34 -07:00
fs afs: Fix uncancelled rxrpc OOB message handler 2026-06-25 10:07:18 -07:00
include net: add the driver-facing netdev_work scheduling API 2026-06-25 10:18:40 -07:00
init Bootconfig updates for v7.2 2026-06-16 17:29:24 +05:30
io_uring Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
ipc kernel-7.2-rc1.misc 2026-06-15 03:05:50 +05:30
kernel tracing latency updates for 7.2: 2026-06-16 17:38:19 +05:30
lib Bootconfig updates for v7.2 2026-06-16 17:29:24 +05:30
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 for-7.2/block-20260615 2026-06-16 13:02:47 +05:30
net vlan: defer real device state propagation to netdev_work 2026-06-25 10:18:40 -07:00
rust for-7.2/block-20260615 2026-06-16 13:02:47 +05:30
samples Driver core changes for 7.2-rc1 2026-06-15 12:41:17 +05:30
scripts linux_kselftest-kunit-7.2-rc1 2026-06-16 16:33:57 +05:30
security Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
sound gpio updates for v7.2-rc1 2026-06-16 07:30:52 +05:30
tools selftests: bonding: add a test for VLAN propagation over a bonded real device 2026-06-25 10:18:40 -07:00
usr kbuild: uapi: also test UAPI headers against C++ compilers 2026-03-25 13:24:42 +01:00
virt vfs-7.2-rc1.misc 2026-06-15 03:59:45 +05:30
.clang-format Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
.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 2026-04-02 16:48:25 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Rust changes for v7.2 2026-06-15 09:25:48 +05:30
.mailmap net: ethernet: qualcomm: ppe: Demote from supported and fix maintainer addresses 2026-06-25 08:46:29 -07:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS fbdev fixes & cleanups for 7.2-rc1: 2026-06-16 08:28:41 +05:30
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 net: ethernet: qualcomm: ppe: Demote from supported and fix maintainer addresses 2026-06-25 08:46:29 -07:00
Makefile slab changes for 7.2 2026-06-16 08:44:43 +05:30
README docs: add AI Coding Assistants documentation 2026-01-06 14:55:06 -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