CVE-2023-53013 is a vulnerability identified in the Linux kernel specifically related to the ptdma driver. The issue arises in the interrupt handler function pt_core_irq_handler(), which can be invoked in interrupt context. Within this context, the function's code path leads to pt_core_execute_cmd(), which attempts to acquire a mutex. Using a mutex in interrupt context is inappropriate because mutexes can sleep, which is not allowed in interrupt context and can cause deadlocks or kernel panics. This improper synchronization mechanism leads to a kernel panic, effectively causing a denial of service (DoS) condition. The vulnerability is resolved by replacing the mutex with a spinlock in pt_core_execute_cmd(), which is suitable for interrupt context as spinlocks do not sleep and allow safe synchronization in such scenarios. The fix has been verified to resolve the kernel panic issue. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability affects the Linux kernel versions identified by the commit hashes provided, indicating it is a recent and specific code regression or flaw.

For European organizations, this vulnerability poses a risk primarily in environments running affected Linux kernel versions with the ptdma driver enabled. The impact is a potential kernel panic leading to system crashes and denial of service. This can disrupt critical services, especially in infrastructure relying on Linux servers for networking, telecommunications, or industrial control systems where ptdma might be in use. Although the vulnerability does not directly allow privilege escalation or data breach, the availability impact can be significant, causing downtime and operational disruption. Organizations in sectors such as telecommunications, cloud service providers, and enterprises with Linux-based infrastructure could face service interruptions. The lack of known exploits reduces immediate risk, but the vulnerability's nature means that any crafted interrupt or hardware interaction triggering the flaw could cause instability. Given the kernel-level nature, recovery from such crashes may require reboots, impacting service continuity.

European organizations should promptly apply the Linux kernel patches that replace the mutex with a spinlock in the ptdma driver's interrupt handler. Since this is a kernel-level fix, updating to the latest stable Linux kernel version containing the patch is the most effective mitigation. For environments where immediate patching is challenging, organizations should audit the use of the ptdma driver and consider disabling or unloading it if not required, to reduce exposure. Monitoring system logs for kernel panics or unusual interrupt-related errors can help detect attempts to trigger this vulnerability. Additionally, implementing robust system restart and recovery procedures will minimize downtime in case of crashes. Organizations should also ensure that their incident response and change management processes include rapid deployment of kernel updates to mitigate such vulnerabilities promptly.