diff options
| author | Muhammad Bilal <meatuni001@gmail.com> | 2026-07-28 17:54:55 +0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-09-01 12:15:16 +0200 |
| commit | ff917923f4fb9c83717ba135ee47d7e4c1567bb7 (patch) | |
| tree | c38fd8fcf58e1937b17fdbc6518b6f8b797fc15a /Documentation/driver-api/thermal/cpu-cooling-api.rst | |
| download | linux-stable-ff917923f4fb9c83717ba135ee47d7e4c1567bb7.tar.gz linux-stable-ff917923f4fb9c83717ba135ee47d7e4c1567bb7.zip | |
staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted
rtw_action_frame_parse() takes a frame_len parameter but never
actually checks it before indexing into the frame body:
const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr);
...
c = frame_body[0];
...
a = frame_body[1];
frame_body already points 24 bytes (sizeof(struct
ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and
frame_body[1] requires frame_len >= 26. A management action frame
shorter than that (e.g. exactly 24 bytes, the minimum a malicious
peer can send) causes a 1-2 byte out-of-bounds read.
This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and
cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass
attacker/user-influenced frame buffers and lengths straight through.
Add the missing length check before frame_body is dereferenced.
Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/driver-api/thermal/cpu-cooling-api.rst')
| -rw-r--r-- | Documentation/driver-api/thermal/cpu-cooling-api.rst | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/Documentation/driver-api/thermal/cpu-cooling-api.rst b/Documentation/driver-api/thermal/cpu-cooling-api.rst new file mode 100644 index 000000000..645d914c4 --- /dev/null +++ b/Documentation/driver-api/thermal/cpu-cooling-api.rst @@ -0,0 +1,107 @@ +======================= +CPU cooling APIs How To +======================= + +Written by Amit Daniel Kachhap <amit.kachhap@linaro.org> + +Updated: 6 Jan 2015 + +Copyright (c) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) + +0. Introduction +=============== + +The generic cpu cooling(freq clipping) provides registration/unregistration APIs +to the caller. The binding of the cooling devices to the trip point is left for +the user. The registration APIs returns the cooling device pointer. + +1. cpu cooling APIs +=================== + +1.1 cpufreq registration/unregistration APIs +-------------------------------------------- + + :: + + struct thermal_cooling_device + *cpufreq_cooling_register(struct cpumask *clip_cpus) + + This interface function registers the cpufreq cooling device with the name + "thermal-cpufreq-%x". This api can support multiple instances of cpufreq + cooling devices. + + clip_cpus: + cpumask of cpus where the frequency constraints will happen. + + :: + + struct thermal_cooling_device + *of_cpufreq_cooling_register(struct cpufreq_policy *policy) + + This interface function registers the cpufreq cooling device with + the name "thermal-cpufreq-%x" linking it with a device tree node, in + order to bind it via the thermal DT code. This api can support multiple + instances of cpufreq cooling devices. + + policy: + CPUFreq policy. + + + :: + + void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) + + This interface function unregisters the "thermal-cpufreq-%x" cooling device. + + cdev: Cooling device pointer which has to be unregistered. + +2. Power models +=============== + +The power API registration functions provide a simple power model for +CPUs. The current power is calculated as dynamic power (static power isn't +supported currently). This power model requires that the operating-points of +the CPUs are registered using the kernel's opp library and the +`cpufreq_frequency_table` is assigned to the `struct device` of the +cpu. If you are using CONFIG_CPUFREQ_DT then the +`cpufreq_frequency_table` should already be assigned to the cpu +device. + +The dynamic power consumption of a processor depends on many factors. +For a given processor implementation the primary factors are: + +- The time the processor spends running, consuming dynamic power, as + compared to the time in idle states where dynamic consumption is + negligible. Herein we refer to this as 'utilisation'. +- The voltage and frequency levels as a result of DVFS. The DVFS + level is a dominant factor governing power consumption. +- In running time the 'execution' behaviour (instruction types, memory + access patterns and so forth) causes, in most cases, a second order + variation. In pathological cases this variation can be significant, + but typically it is of a much lesser impact than the factors above. + +A high level dynamic power consumption model may then be represented as:: + + Pdyn = f(run) * Voltage^2 * Frequency * Utilisation + +f(run) here represents the described execution behaviour and its +result has a units of Watts/Hz/Volt^2 (this often expressed in +mW/MHz/uVolt^2) + +The detailed behaviour for f(run) could be modelled on-line. However, +in practice, such an on-line model has dependencies on a number of +implementation specific processor support and characterisation +factors. Therefore, in initial implementation that contribution is +represented as a constant coefficient. This is a simplification +consistent with the relative contribution to overall power variation. + +In this simplified representation our model becomes:: + + Pdyn = Capacitance * Voltage^2 * Frequency * Utilisation + +Where `capacitance` is a constant that represents an indicative +running time dynamic power coefficient in fundamental units of +mW/MHz/uVolt^2. Typical values for mobile CPUs might lie in range +from 100 to 500. For reference, the approximate values for the SoC in +ARM's Juno Development Platform are 530 for the Cortex-A57 cluster and +140 for the Cortex-A53 cluster. |
