CVE-2023-53051 is a vulnerability identified in the Linux kernel's device mapper cryptographic module (dm-crypt), specifically within the dmcrypt_write() function. The issue arises because the function contains a loop that can run for an unbounded amount of time without yielding CPU resources, leading to a potential soft lockup condition. This is evidenced by kernel watchdog warnings indicating that a CPU core is stuck for an extended period (e.g., 23 seconds) during the execution of dmcrypt_write. The root cause is the absence of a call to cond_resched(), a kernel function that allows the scheduler to preempt the current task and schedule others, within this loop. Without this call, the CPU core executing dmcrypt_write may become unresponsive, causing system instability or degraded performance. The vulnerability does not appear to be exploitable for privilege escalation or code execution but can cause denial of service (DoS) by locking up CPU resources. The fix involves adding cond_resched() calls inside the loop in dmcrypt_write to ensure the kernel scheduler can interrupt the task and maintain system responsiveness. This patch prevents the soft lockup condition and improves the stability of systems using dm-crypt for disk encryption. No known exploits in the wild have been reported, and no CVSS score has been assigned yet. The vulnerability affects Linux kernel versions identified by the commit hash dc2676210c425ee8e5cb1bec5bc84d004ddf4179 and likely other versions prior to the patch.

For European organizations, this vulnerability primarily poses a risk of denial of service through system instability or unresponsiveness on Linux systems utilizing dm-crypt for disk encryption. Many enterprises, government agencies, and critical infrastructure operators in Europe rely on Linux servers and workstations with encrypted storage for data protection and regulatory compliance (e.g., GDPR). A soft lockup in dmcrypt_write could lead to degraded performance, system hangs, or forced reboots, disrupting business operations and potentially causing data availability issues. While it does not directly compromise confidentiality or integrity, the resulting downtime or instability could impact services, especially in environments with high I/O workloads or heavy encryption usage. Organizations running Linux-based virtual machines, cloud infrastructure, or container hosts with encrypted volumes are also at risk. The absence of known exploits reduces immediate threat levels, but unpatched systems remain vulnerable to accidental or induced DoS conditions, which could be leveraged in targeted attacks or during maintenance windows.

European organizations should prioritize applying the official Linux kernel patches that introduce cond_resched() calls within dmcrypt_write to prevent CPU soft lockups. System administrators must ensure that all Linux systems using dm-crypt are updated to kernel versions containing this fix. For environments where immediate patching is challenging, monitoring kernel logs for soft lockup warnings related to dmcrypt_write can help detect potential issues early. Additionally, workload balancing and limiting I/O-intensive encrypted disk operations may reduce the likelihood of triggering the vulnerability. Organizations should also review and test backup and recovery procedures to mitigate the impact of potential system hangs or reboots. Engaging with Linux distribution vendors for timely security updates and verifying that custom kernels incorporate this fix is critical. Finally, integrating this vulnerability into vulnerability management and patching workflows will ensure ongoing compliance and risk reduction.