CVE-2024-56620 is a vulnerability identified in the Linux kernel specifically affecting the Qualcomm UFS (Universal Flash Storage) driver component. The issue arises from improper handling of platform MSI (Message Signaled Interrupts) resources in the UFS Qualcomm driver code path. When the ESI (Enhanced Secure Interrupt) feature is not enabled, the driver attempts to free platform MSIs incorrectly, leading to a NULL pointer dereference. This results in a kernel panic or crash, as indicated by the call trace involving mutex_lock, platform_device_msi_free_irqs_all, and ufs_qcom_remove functions. The vulnerability manifests during device removal or driver unregistration operations, where the platform driver unregisters and attempts to free resources that were never properly allocated or initialized. This flaw can cause a denial of service (DoS) condition by crashing the kernel, potentially affecting system stability and availability. The vulnerability is present in specific Linux kernel versions identified by the commit hash 519b6274a7775f5fe00a086f189efb8f063467d1. No public exploits are known at this time, and no CVSS score has been assigned yet. The issue is resolved by ensuring that platform MSIs are only freed when ESI is enabled, preventing the NULL pointer dereference. This vulnerability is relevant for systems running Linux kernels with Qualcomm UFS drivers, particularly on ARM64 architectures where Qualcomm chipsets are common. It is a low-level kernel flaw that requires local privileges to trigger, typically during module unload or device removal sequences.

For European organizations, the primary impact of CVE-2024-56620 is the risk of system instability and denial of service on Linux systems using Qualcomm UFS storage drivers. This could affect servers, embedded devices, and workstations that rely on Qualcomm hardware and Linux kernels with the vulnerable driver. The denial of service could disrupt critical infrastructure, industrial control systems, or cloud services that utilize affected hardware, leading to operational downtime and potential data availability issues. Although this vulnerability does not directly expose confidentiality or integrity risks, the loss of availability can have significant business impact, especially in sectors like telecommunications, manufacturing, and public services where Qualcomm-based embedded Linux devices are deployed. The lack of known exploits reduces immediate risk, but the vulnerability could be leveraged in targeted attacks or combined with other vulnerabilities to escalate impact. European organizations with Linux-based Qualcomm hardware should prioritize patching to maintain system reliability and prevent service interruptions.

1. Apply the latest Linux kernel updates that include the fix for CVE-2024-56620, ensuring the Qualcomm UFS driver only frees platform MSIs when ESI is enabled. 2. Audit and inventory Linux systems to identify those running affected kernel versions with Qualcomm UFS drivers, focusing on ARM64 platforms. 3. For embedded or specialized devices, coordinate with hardware vendors or OEMs to obtain patched firmware or kernel versions. 4. Implement kernel module loading/unloading policies to restrict untrusted users from triggering device removal or module unload operations that could exploit this vulnerability. 5. Monitor system logs for kernel panics or crashes related to ufs_qcom driver activity as an early indicator of attempted exploitation. 6. In environments where patching is delayed, consider isolating affected systems or limiting access to reduce risk of local exploitation. 7. Incorporate this vulnerability into vulnerability management and incident response plans to ensure rapid remediation if exploitation attempts are detected.