CVE-2024-56534 is a memory leak vulnerability identified in the Linux kernel's ISO filesystem (isofs) module, specifically related to the handling of the iocharset option. The vulnerability arises because the memory allocated for the iocharset option (opt->iocharset) is freed only within the isofs_fill_super function. However, there are scenarios where this function is not invoked, such as when mounting fails due to a read-only state change prevention in the get_tree_bdev_flags function. In these cases, the allocated memory for iocharset is not released, resulting in a memory leak. The leak is caused by the failure to free opt->iocharset when isofs_fill_super is bypassed. The proposed fix involves moving the memory freeing operation to the isofs_free_fc function, which is called more reliably during cleanup, ensuring that the allocated memory is freed regardless of the mount outcome. This vulnerability does not directly lead to code execution or privilege escalation but can cause resource exhaustion over time if exploited repeatedly or on systems with frequent mount operations involving isofs. The vulnerability affects Linux kernel versions identified by the commit hash 1b17a46c9243e9421ee1ac6d628604bbc4ae2201 and likely other versions containing the affected isofs code. No known exploits are reported in the wild at the time of publication.

For European organizations, the impact of CVE-2024-56534 is primarily related to system stability and resource management rather than direct compromise of confidentiality or integrity. Systems that frequently mount ISO filesystems, such as those used in media distribution, embedded systems, or virtual environments, may experience gradual memory exhaustion leading to degraded performance or potential denial of service due to kernel memory leaks. This can affect critical infrastructure or services relying on Linux servers, especially in sectors like telecommunications, manufacturing, and public services where Linux is prevalent. While the vulnerability does not enable direct remote exploitation or privilege escalation, the resulting memory leak could be leveraged as part of a broader attack chain or cause operational disruptions. European organizations with large Linux deployments should be aware of this issue to maintain system reliability and avoid unexpected outages.

To mitigate this vulnerability, organizations should apply the official Linux kernel patches that move the freeing of opt->iocharset to the isofs_free_fc function, ensuring proper memory cleanup. System administrators should update their Linux kernels to the latest stable versions that include this fix. Additionally, monitoring kernel memory usage and logs for unusual memory consumption patterns related to isofs mounts can help detect potential exploitation or memory leaks. For environments where patching is delayed, limiting the mounting of ISO filesystems or restricting mount operations to trusted users can reduce exposure. Automated configuration management and kernel update processes should be employed to ensure timely deployment of security patches. Finally, testing kernel updates in staging environments before production rollout is recommended to avoid unintended disruptions.