CVE-2023-52765 is a medium-severity vulnerability affecting the Linux kernel's Qualcomm SPMI PMIC (Power Management Integrated Circuit) driver, specifically the revid implementation in the mfd: qcom-spmi-pmic module. The vulnerability arises from multiple flawed assumptions and unsafe coding practices in the handling of sibling device driver data. First, the code incorrectly assumes that if a sibling base device is registered, it is also bound to a driver, which may not be true due to asynchronous or deferred probing. This can lead to a NULL-pointer dereference when accessing unbound device driver data. Second, the driver accesses sibling device data without proper locking mechanisms, risking use-after-free conditions if the driver data is freed concurrently, such as during driver unbinding. Third, the implementation leaks references to sibling device structures by repeatedly looking them up without proper caching, potentially causing resource leaks and instability. The fix involves reimplementing the revid lookup to occur only during the PMIC device probe. The base device fetches the revid information directly from hardware, while secondary SPMI devices retrieve and cache this data from the base device, ensuring safe concurrent access. If the base device is not yet probed, probing of secondary devices is deferred to avoid unsafe access. This vulnerability is categorized under CWE-476 (NULL Pointer Dereference) and has a CVSS v3.1 score of 6.2, indicating a medium severity. The attack vector is local (AV:L), requiring local access but no privileges (PR:N) or user interaction (UI:N). The impact affects availability (A:H) but not confidentiality or integrity. No known exploits are currently reported in the wild.

For European organizations, the impact of CVE-2023-52765 primarily concerns systems running Linux kernels with Qualcomm SPMI PMIC drivers, commonly found in embedded devices, mobile platforms, and specialized hardware using Qualcomm chipsets. The vulnerability can cause system instability or crashes due to NULL-pointer dereferences and use-after-free conditions, leading to denial of service (DoS). This can disrupt critical services, especially in sectors relying on embedded Linux devices such as telecommunications infrastructure, industrial control systems, and IoT deployments. While the vulnerability does not directly compromise confidentiality or integrity, the availability impact can cause operational downtime, affecting business continuity and service reliability. Organizations with Linux-based infrastructure that includes Qualcomm hardware should be aware of potential disruptions and plan accordingly. Since exploitation requires local access, the threat is more relevant in environments where attackers or malicious insiders can gain local system access, such as multi-tenant data centers, shared hosting, or poorly segmented networks.

1. Apply the official Linux kernel patches that address CVE-2023-52765 as soon as they become available from trusted sources or Linux distribution vendors. 2. For embedded or specialized devices, coordinate with hardware vendors or OEMs to obtain updated firmware or kernel versions incorporating the fix. 3. Implement strict access controls and segmentation to limit local access to devices running vulnerable Linux kernels, reducing the risk of local exploitation. 4. Monitor system logs and kernel messages for signs of NULL-pointer dereferences or unexpected device driver crashes that could indicate attempted exploitation. 5. Employ runtime protection mechanisms such as kernel address space layout randomization (KASLR) and memory protection features to mitigate the impact of memory corruption vulnerabilities. 6. In environments where patching is delayed, consider disabling or isolating the Qualcomm SPMI PMIC driver if feasible, to prevent triggering the vulnerable code paths. 7. Conduct thorough testing of updated kernels in staging environments to ensure stability and compatibility before wide deployment.