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authorMuhammad Bilal <meatuni001@gmail.com>2026-07-28 17:54:55 +0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2026-09-01 12:15:16 +0200
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treec38fd8fcf58e1937b17fdbc6518b6f8b797fc15a /Documentation/driver-api/interconnect.rst
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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>
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+.. SPDX-License-Identifier: GPL-2.0
+
+=====================================
+Generic System Interconnect Subsystem
+=====================================
+
+Introduction
+------------
+
+This framework is designed to provide a standard kernel interface to control
+the settings of the interconnects on an SoC. These settings can be throughput,
+latency and priority between multiple interconnected devices or functional
+blocks. This can be controlled dynamically in order to save power or provide
+maximum performance.
+
+The interconnect bus is hardware with configurable parameters, which can be
+set on a data path according to the requests received from various drivers.
+An example of interconnect buses are the interconnects between various
+components or functional blocks in chipsets. There can be multiple interconnects
+on an SoC that can be multi-tiered.
+
+Below is a simplified diagram of a real-world SoC interconnect bus topology.
+
+::
+
+ +----------------+ +----------------+
+ | HW Accelerator |--->| M NoC |<---------------+
+ +----------------+ +----------------+ |
+ | | +------------+
+ +-----+ +-------------+ V +------+ | |
+ | DDR | | +--------+ | PCIe | | |
+ +-----+ | | Slaves | +------+ | |
+ ^ ^ | +--------+ | | C NoC |
+ | | V V | |
+ +------------------+ +------------------------+ | | +-----+
+ | |-->| |-->| |-->| CPU |
+ | |-->| |<--| | +-----+
+ | Mem NoC | | S NoC | +------------+
+ | |<--| |---------+ |
+ | |<--| |<------+ | | +--------+
+ +------------------+ +------------------------+ | | +-->| Slaves |
+ ^ ^ ^ ^ ^ | | +--------+
+ | | | | | | V
+ +------+ | +-----+ +-----+ +---------+ +----------------+ +--------+
+ | CPUs | | | GPU | | DSP | | Masters |-->| P NoC |-->| Slaves |
+ +------+ | +-----+ +-----+ +---------+ +----------------+ +--------+
+ |
+ +-------+
+ | Modem |
+ +-------+
+
+Terminology
+-----------
+
+Interconnect provider is the software definition of the interconnect hardware.
+The interconnect providers on the above diagram are M NoC, S NoC, C NoC, P NoC
+and Mem NoC.
+
+Interconnect node is the software definition of the interconnect hardware
+port. Each interconnect provider consists of multiple interconnect nodes,
+which are connected to other SoC components including other interconnect
+providers. The point on the diagram where the CPUs connect to the memory is
+called an interconnect node, which belongs to the Mem NoC interconnect provider.
+
+Interconnect endpoints are the first or the last element of the path. Every
+endpoint is a node, but not every node is an endpoint.
+
+Interconnect path is everything between two endpoints including all the nodes
+that have to be traversed to reach from a source to destination node. It may
+include multiple master-slave pairs across several interconnect providers.
+
+Interconnect consumers are the entities which make use of the data paths exposed
+by the providers. The consumers send requests to providers requesting various
+throughput, latency and priority. Usually the consumers are device drivers, that
+send request based on their needs. An example for a consumer is a video decoder
+that supports various formats and image sizes.
+
+Interconnect providers
+----------------------
+
+Interconnect provider is an entity that implements methods to initialize and
+configure interconnect bus hardware. The interconnect provider drivers should
+be registered with the interconnect provider core.
+
+.. kernel-doc:: include/linux/interconnect-provider.h
+
+.. kernel-doc:: drivers/interconnect/core.c
+ :functions: icc_provider_init icc_provider_register icc_provider_deregister
+ icc_node_create icc_node_create_dyn icc_node_destroy
+ icc_node_add icc_node_del icc_nodes_remove icc_node_set_name
+ icc_link_create icc_link_nodes
+
+Interconnect consumers
+----------------------
+
+Interconnect consumers are the clients which use the interconnect APIs to
+get paths between endpoints and set their bandwidth/latency/QoS requirements
+for these interconnect paths.
+
+.. kernel-doc:: drivers/interconnect/core.c
+ :functions: devm_of_icc_get of_icc_get_by_index of_icc_get icc_get
+ icc_put icc_enable icc_disable icc_set_bw icc_set_tag
+ icc_get_name
+
+.. kernel-doc:: drivers/interconnect/bulk.c
+
+Interconnect debugfs interfaces
+-------------------------------
+
+Like several other subsystems interconnect will create some files for debugging
+and introspection. Files in debugfs are not considered ABI so application
+software shouldn't rely on format details change between kernel versions.
+
+``/sys/kernel/debug/interconnect/interconnect_summary``:
+
+Show all interconnect nodes in the system with their aggregated bandwidth
+request. Indented under each node show bandwidth requests from each device.
+
+``/sys/kernel/debug/interconnect/interconnect_graph``:
+
+Show the interconnect graph in the graphviz dot format. It shows all
+interconnect nodes and links in the system and groups together nodes from the
+same provider as subgraphs. The format is human-readable and can also be piped
+through dot to generate diagrams in many graphical formats::
+
+ $ cat /sys/kernel/debug/interconnect/interconnect_graph | \
+ dot -Tsvg > interconnect_graph.svg
+
+The ``test-client`` directory provides interfaces for issuing BW requests to
+any arbitrary path. Note that for safety reasons, this feature is disabled by
+default without a Kconfig to enable it. Enabling it requires code changes to
+``#define INTERCONNECT_ALLOW_WRITE_DEBUGFS``. Example usage::
+
+ cd /sys/kernel/debug/interconnect/test-client/
+
+ # Configure node endpoints for the path from CPU to DDR on
+ # qcom/sm8550.
+ echo chm_apps > src_node
+ echo ebi > dst_node
+
+ # Get path between src_node and dst_node. This is only
+ # necessary after updating the node endpoints.
+ echo 1 > get
+
+ # Set desired BW to 1GBps avg and 2GBps peak.
+ echo 1000000 > avg_bw
+ echo 2000000 > peak_bw
+
+ # Vote for avg_bw and peak_bw on the latest path from "get".
+ # Voting for multiple paths is possible by repeating this
+ # process for different nodes endpoints.
+ echo 1 > commit