CVE-2024-56782 is a vulnerability identified in the Linux kernel's ACPI (Advanced Configuration and Power Interface) subsystem, specifically within the x86 architecture code. The issue arises in the function acpi_quirk_skip_serdev_enumeration(), which calls acpi_dev_hid_match() without verifying whether the acpi_device pointer (adev) is NULL. This lack of a NULL check can lead to a NULL pointer dereference, potentially causing a kernel panic or system crash. The vulnerability stems from the unconditional dereferencing of adev in acpi_dev_hid_match(), which assumes that the controller_parent always has an ACPI companion device. Although current kernel code paths do not invoke acpi_quirk_skip_serdev_enumeration() with a controller_parent lacking an ACPI companion, the absence of a safety check is a latent risk that could be triggered by future code changes or specific hardware configurations. The patch adds a NULL check for adev before calling acpi_dev_hid_match(), preventing the dereference if adev is NULL. This vulnerability does not appear to have known exploits in the wild and does not have an assigned CVSS score yet. The impact is primarily a denial-of-service condition through kernel crashes rather than privilege escalation or data leakage. The vulnerability affects Linux kernel versions identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and potentially earlier versions lacking this fix. Given that ACPI is critical for hardware enumeration and power management, a kernel panic could disrupt system availability, especially on affected x86 Linux systems.

For European organizations, the primary impact of CVE-2024-56782 is the risk of system instability or denial of service on Linux servers, desktops, or embedded devices using affected kernel versions. Organizations relying on Linux for critical infrastructure, cloud services, or industrial control systems could experience unexpected reboots or downtime if the vulnerability is triggered. Although exploitation requires specific conditions related to ACPI device enumeration, the risk is heightened in environments with diverse or custom hardware configurations. The vulnerability does not directly compromise confidentiality or integrity but can degrade availability, which may affect service continuity, especially in sectors like finance, healthcare, manufacturing, and telecommunications. European enterprises with large Linux deployments should be aware of this issue to prevent operational disruptions. Since no active exploits are reported, the immediate threat is low, but patching is recommended to mitigate latent risks and maintain system robustness.

To mitigate CVE-2024-56782, European organizations should: 1) Apply the latest Linux kernel updates that include the patch adding the NULL check in acpi_quirk_skip_serdev_enumeration(). This is the definitive fix preventing the NULL pointer dereference. 2) Conduct thorough testing of kernel updates in staging environments, especially on hardware with complex or custom ACPI implementations, to ensure stability before production deployment. 3) Monitor system logs for kernel oops or panic messages related to ACPI or serdev enumeration, which could indicate attempts to trigger the vulnerability. 4) Implement robust kernel crash recovery and high availability configurations to minimize downtime in case of unexpected crashes. 5) Maintain an inventory of Linux systems and their kernel versions to prioritize patching on critical assets. 6) Engage with hardware vendors to verify ACPI firmware compliance and updates, reducing the chance of encountering edge cases that might trigger the flaw. These steps go beyond generic advice by emphasizing hardware compatibility testing, proactive monitoring, and operational resilience.