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Lachlan Hodges 00f623647c wifi: mac80211: don't seed an S1G sta's last_rate
When initialising the rate control system, ieee80211_s1g_sta_rate_init()
is called for S1G stations during association where it initialises a
last rate of type STA_STATS_RATE_TYPE_S1G but does not initialise
nss, mcs bw etc. Since the last_rate no longer has a value equivalent
to STA_STATS_RATE_INVALID, the invalid rate will be decoded and
the NL80211_STA_INFO_RX_BITRATE flag will be set.

As a result, there is a period during association before the first
data frame is rx'ed where the seeded value is overwritten by
ieee80211_rx_h_sta_process() while this invalid last_rate lives. If
the sta is desroyed during this process, nl80211_put_sta_rate() will
call into cfg80211_calculate_bitrate() and attempt to calculate
the bitrate using the invalid last_rate leading to a WARN:

4,336,675067400,-;------------[ cut here ]------------
4,337,675067524,-;WARNING: net/wireless/util.c:1960 at cfg80211_calculate_bitrate+0x4d8/0x8b0 [cfg80211], CPU#3: kworker/u16:3/874
4,338,675068176,-;invalid rate bw=0, mcs=0, nss=0
[snip loaded modules]
4,341,675068954,-;Hardware name: BCM2711
4,342,675068961,-;Workqueue: events_unbound cfg80211_wiphy_work [cfg80211]
4,343,675069386,-;Call trace:
4,344,675069392,-; unwind_backtrace from show_stack+0x10/0x14
4,345,675069440,-; show_stack from dump_stack_lvl+0xa8/0xb8
4,346,675069475,-; dump_stack_lvl from __warn+0x90/0x224
4,347,675069517,-; __warn from warn_slowpath_fmt+0x130/0x1a8
4,348,675069559,-; warn_slowpath_fmt from cfg80211_calculate_bitrate+0x4d8/0x8b0 [cfg80211]
4,349,675070005,-; cfg80211_calculate_bitrate [cfg80211] from nl80211_put_sta_rate+0x48/0x590 [cfg80211]
4,350,675070819,-; nl80211_put_sta_rate [cfg80211] from nl80211_put_sta_info_common+0x4f4/0xd50 [cfg80211]
4,351,675071616,-; nl80211_put_sta_info_common [cfg80211] from nl80211_send_station.constprop.0+0x114/0x424 [cfg80211]
4,352,675072427,-; nl80211_send_station.constprop.0 [cfg80211] from cfg80211_del_sta_sinfo+0xc4/0x368 [cfg80211]
4,353,675073222,-; cfg80211_del_sta_sinfo [cfg80211] from __sta_info_destroy_part2+0x108/0x2c0 [mac80211]
4,354,675074178,-; __sta_info_destroy_part2 [mac80211] from sta_info_destroy_addr+0x4c/0x88 [mac80211]
4,355,675075243,-; sta_info_destroy_addr [mac80211] from ieee80211_destroy_assoc_data+0x194/0x2d8 [mac80211]
4,356,675075920,-; ieee80211_destroy_assoc_data [mac80211] from ieee80211_rx_mgmt_assoc_resp+0x220/0x1d4c [mac80211]
4,357,675076558,-; ieee80211_rx_mgmt_assoc_resp [mac80211] from ieee80211_iface_work+0x1c0/0x5d0 [mac80211]
4,358,675077187,-; ieee80211_iface_work [mac80211] from cfg80211_wiphy_work+0x110/0x368 [cfg80211]
4,359,675077763,-; cfg80211_wiphy_work [cfg80211] from process_one_work+0x260/0x868
4,360,675078022,-; process_one_work from worker_thread+0x1bc/0x3ec
4,361,675078042,-; worker_thread from kthread+0x120/0x154
4,362,675078060,-; kthread from ret_from_fork+0x14/0x20
4,363,675078074,-;Exception stack(0xf0ac1fb0 to 0xf0ac1ff8)
4,364,675078081,-;1fa0:                                     00000000 00000000 00000000 00000000
4,365,675078088,-;1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
4,366,675078093,-;1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
4,367,675080226,-;irq event stamp: 15780967
4,368,675080287,-;hardirqs last  enabled at (15780975): [<c050c154>] __up_console_sem+0x50/0x60
4,369,675080395,-;hardirqs last disabled at (15780982): [<c050c140>] __up_console_sem+0x3c/0x60
4,370,675080497,-;softirqs last  enabled at (15780966): [<c0476f14>] handle_softirqs+0x398/0x650
4,371,675080608,-;softirqs last disabled at (15780939): [<c0477388>] __irq_exit_rcu+0x150/0x1f0
4,372,675080715,-;---[ end trace 0000000000000000 ]---

To fix, we can simply not seed this psuedo rate. It was originally
implemented to avoid errornous paths that S1G shouldn't take, but those
have since been fixed / cleaned up. While we are here, we also don't
need to initialise the tx side's last rate with
IEEE80211_TX_RC_S1G_MCS (which is equivalent to
IEEE80211_TX_RC_VHT_MCS). The entire tx reporting side does not
support S1G widths and is assumed to be handled by the driver so
we can just remove the entire function.

Fixes: 12bf8fad4c ("mac80211: initialize last_rate for S1G STAs")
Signed-off-by: Lachlan Hodges <lachlan.hodges@morsemicro.com>
Link: https://patch.msgid.link/20260827054456.254573-1-lachlan.hodges@morsemicro.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
History 2026-09-04 09:52:24 +02:00
arch - Fix UM build regression caused by the removal of the UM 2026-08-30 10:19:11 -07:00
block for-7.3/block-20260819 2026-08-20 13:55:16 -07:00
certs treewide: fix indentation and whitespace in Kconfig files 2026-05-28 21:24:42 -07:00
crypto This push fixes a memory allocation overrun in crypto acomp. 2026-08-28 09:28:40 -07:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-09-03 10:48:16 -07:00
drivers Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-09-03 10:48:16 -07:00
fs - Serialize truncate, fallocate, and mmap fault paths with 2026-09-03 08:10:04 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-09-03 10:48:16 -07:00
init Bootconfig updates for v7.3: 2026-08-25 08:59:09 -07:00
io_uring io_uring-7.3-20260828 2026-08-28 16:51:14 -07:00
ipc mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
kernel workqueue: Fixes for v7.3-rc1 2026-08-31 14:38:40 -07:00
lib mm.git review status for linus..mm-stable 2026-08-27 09:17:06 -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.git review status for linus..mm-stable 2026-08-27 09:17:06 -07:00
net wifi: mac80211: don't seed an S1G sta's last_rate 2026-09-04 09:52:24 +02:00
rust Rust fixes for v7.3 2026-08-30 09:47:39 -07:00
samples tracing fixes for v7.3: 2026-08-30 09:22:00 -07:00
scripts Coccinelle patches for Linux v7.3 2026-08-30 10:42:40 -07:00
security hardening: Default randstruct off with rust for better allmodconfig support 2026-09-01 16:01:35 -07:00
sound sound fixes for 7.3-rc1 2026-08-28 10:01:02 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-09-03 10:48:16 -07:00
usr usr: Correct a spelling by changing a letter 2026-08-05 14:51:58 +02:00
virt Arm: 2026-08-25 11:48:04 -07:00
.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 scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore .get_maintainer.ignore: add Nathan Chancellor 2026-08-03 21:10:12 -07:00
.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 CREDITS/mailmap: add some info about Darrick J. Wong 2026-08-30 10:29:08 -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 - Mark the mpc85xx and ThunderX EDAC drivers as orphaned due to lack of 2026-08-31 20:10:39 -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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-09-03 10:48:16 -07:00
Makefile Linux 7.3-rc1 2026-08-30 13:34:40 -07:00
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?
============

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* New Kernel Developer: Getting started with kernel development
* Academic Researcher: Studying kernel internals and architecture
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* System Administrator: Configuring and troubleshooting
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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
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---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
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* 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

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--------------------

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
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----------

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* Maintainer Handbook: Documentation/maintainer/index.rst
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---------------

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* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

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-----------------------

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* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
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* Module Signing: Documentation/admin-guide/module-signing.rst
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-------------------

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,
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=========================

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