CVE-2026-23090 in Linux
Summary
by MITRE • 02/04/2026
In the Linux kernel, the following vulnerability has been resolved:
slimbus: core: fix device reference leak on report present
Slimbus devices can be allocated dynamically upon reception of report-present messages.
Make sure to drop the reference taken when looking up already registered devices.
Note that this requires taking an extra reference in case the device has not yet been registered and has to be allocated.
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Analysis
by VulDB Data Team • 05/03/2026
The vulnerability identified as CVE-2026-23090 represents a memory management issue within the Linux kernel's Slimbus subsystem, specifically affecting the core component responsible for device handling and registration. This flaw manifests as a device reference leak that occurs during the processing of report-present messages, which are fundamental to the dynamic allocation and management of Slimbus devices in real-time systems. The Slimbus protocol is commonly utilized in embedded systems and mobile devices for connecting audio and multimedia components, making this vulnerability particularly concerning for automotive infotainment systems, smartphones, and other consumer electronics that rely on this communication standard.
The technical root cause of this vulnerability stems from improper reference counting within the Slimbus core driver's device lookup and allocation logic. When the system receives a report-present message indicating the presence of a new Slimbus device, the kernel attempts to locate any existing registered device that matches the incoming message. However, the implementation fails to properly release the reference count on devices that are already registered, leading to a gradual accumulation of unreleased references in memory. This memory leak occurs because the code correctly takes an additional reference when allocating new devices that have not yet been registered, but fails to balance this operation when dealing with existing registered devices, creating a reference counting inconsistency that can eventually lead to resource exhaustion.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as it can lead to system instability and potential denial of service conditions in embedded environments where memory resources are constrained. The reference leak accumulates over time as more report-present messages are processed, particularly in systems with frequent device discovery and connection events. This can result in progressive memory degradation that may ultimately cause the system to become unresponsive or crash when memory resources are exhausted. The vulnerability is particularly dangerous in automotive applications where Slimbus is used for critical audio systems, or in mobile devices where system responsiveness is paramount for user experience and device functionality.
Mitigation strategies for CVE-2026-23090 should focus on implementing proper reference counting mechanisms within the Slimbus core driver, ensuring that every reference taken during device lookup operations is appropriately released. System administrators and device manufacturers should prioritize applying kernel updates that contain the fixed implementation, which properly balances reference counts for both newly allocated devices and existing registered devices. The fix aligns with common security best practices for reference counting and memory management, addressing a fundamental flaw that could be exploited to cause system instability. This vulnerability demonstrates the importance of careful resource management in kernel space code and highlights the need for comprehensive testing of reference counting logic in dynamic device allocation scenarios. The issue also relates to CWE-404, which addresses improper resource management, and could potentially be leveraged by adversaries to perform resource exhaustion attacks against embedded systems using Slimbus communication protocols.