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Currently, nl80211_dump_station() relies on the netlink callback's generic args array (cb->args[2]) to track the station index during dumps. It also processes the entire sinfo structure and transmits it to userspace immediately in a single pass. This approach creates a bottleneck for MLO. When an MLD station has multiple active links, the aggregated station information, combined with the individual per-link statistics, can easily exceed the maximum netlink message size limits. The current monolithic dump iteration cannot pause and resume mid-station to fragment these large per-link statistics across multiple netlink messages. Introduce a stateful context structure (struct nl80211_dump_station_ctx) allocated during the dump to track the iteration state. Store the context pointer directly at cb->args[2], following the same pattern as nl80211_dump_wiphy which stores its state pointer at cb->args[0]. Move the station index (sta_idx) tracking and the sinfo payload into this context. The per-station netlink message is built inline in the loop: common header attributes are assembled directly, then nl80211_put_sta_info_common() adds the STA_INFO payload. Furthermore, move the NL80211_CMD_GET_STATION command definition from genl_small_ops to genl_ops to natively support the .done callback. Implement nl80211_dump_station_done() to ensure the newly allocated state context and its deeply allocated sinfo payload are safely freed when the dump concludes or is aborted prematurely by userspace. Note that the previous dump path used nl80211_send_station(), which included NL80211_ATTR_IE and NL80211_ATTR_RESP_IE. These attributes are not carried forward in this implementation. As documented, association response IEs (assoc_resp_ies) are only relevant at station creation time (e.g. via cfg80211_new_sta()) to notify userspace about association details, and are not expected to be part of get_station()/dump_station() callbacks. Aligning with this expectation, these IEs are intentionally omitted here. This refactoring maintains the existing netlink batching performance while laying the stateful foundation required for per-link statistics fragmentation in subsequent patches. At out_err_release, cfg80211_sinfo_release_content() frees any dynamically allocated sub-fields inside ctx->sinfo (including per-link pointers in sinfo.links[]). Without the subsequent memset, those pointers remain non-NULL in the embedded sinfo. When the dump concludes or is aborted, nl80211_dump_station_done() calls cfg80211_sinfo_release_content() a second time on the same ctx->sinfo, which would free the already-released link memory. The memset(&ctx->sinfo, 0, sizeof(ctx->sinfo)) zeroes all pointers so the second release call hits kfree(NULL), which is a harmless no-op. Signed-off-by: P Praneesh <praneesh.p@oss.qualcomm.com> Link: https://patch.msgid.link/20260614051739.3979947-4-praneesh.p@oss.qualcomm.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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. 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