CVE-2024-35806 is a vulnerability identified in the Linux kernel, specifically within the Freescale (fsl) Queue Manager (qbman) subsystem related to interrupt handling and locking mechanisms. The issue arises from improper management of interrupt requests (IRQs) when acquiring the cgr_lock, a lock used to protect certain critical sections in the qbman code. The vulnerability is rooted in the fact that while some functions such as qman_update_cgr and qman_delete_cgr correctly disable interrupts when taking the cgr_lock to prevent deadlocks, other code paths fail to do so. This inconsistency can lead to deadlocks or race conditions because smp_call_function_single disables IRQs when executing callbacks, and if IRQs are not disabled elsewhere when taking the same lock, it can cause lock contention or system instability. The fix involves ensuring that IRQs are always disabled when acquiring the cgr_lock, harmonizing the locking behavior across all relevant code paths. This vulnerability affects multiple Linux kernel versions, as indicated by the affected commit hashes, and was published on May 17, 2024. No known exploits are currently reported in the wild. The vulnerability does not have an assigned CVSS score yet, but it is recognized by the Linux project and CISA enrichment indicates its significance. The technical nature of the flaw suggests it is a low-level kernel synchronization issue that could impact system stability and reliability rather than direct remote code execution or privilege escalation.

For European organizations, the impact of CVE-2024-35806 primarily concerns system stability and availability rather than direct data breaches or privilege escalations. Organizations running Linux-based infrastructure, especially those using kernels with the affected qbman subsystem (commonly found in embedded systems, networking equipment, or specialized hardware using Freescale processors), may experience deadlocks or system hangs if the vulnerability is triggered. This can lead to downtime or degraded performance of critical services. In sectors such as telecommunications, industrial control systems, or cloud service providers that rely on Linux kernels with qbman support, this could disrupt operations or service availability. Although no direct exploitation is known, the risk of deadlocks in kernel code can complicate incident response and recovery, potentially increasing operational costs and impacting service level agreements (SLAs). The vulnerability does not appear to allow unauthorized access or data compromise but could indirectly affect business continuity if exploited or triggered by faulty software or hardware interactions.

To mitigate CVE-2024-35806, organizations should: 1) Apply the official Linux kernel patches that address the IRQ disabling inconsistency when taking the cgr_lock as soon as they are available from trusted Linux kernel maintainers or their Linux distribution vendors. 2) For embedded or specialized systems using Freescale processors and qbman, coordinate with hardware vendors to obtain updated firmware or kernel versions incorporating the fix. 3) Conduct thorough testing of updated kernels in staging environments to ensure stability and compatibility before deployment in production. 4) Monitor system logs and kernel messages for signs of deadlocks or IRQ-related errors that could indicate attempts to trigger this issue. 5) Implement robust backup and recovery procedures to minimize downtime in case of system hangs. 6) Limit kernel-level debugging or development access to trusted personnel to reduce the risk of inadvertent triggering of the vulnerability. 7) Maintain up-to-date inventory of Linux kernel versions and affected hardware to prioritize patching efforts effectively.