CVE-2024-53045 is a vulnerability identified in the Linux kernel's ALSA System on Chip (ASoC) layer, specifically within the Dynamic Audio Power Management (DAPM) subsystem. The issue arises in the dapm_widget_list_create function, where the widgets array in the snd_soc_dapm_widget_list structure is annotated with a __counted_by attribute that references the num_widgets variable for bounds checking. This attribute is critical for the kernel's Undefined Behavior Sanitizer (UBSAN) to verify memory safety. The vulnerability occurs because num_widgets is not properly initialized before the widgets array is populated. Consequently, the bounds checker may either emit warnings or, if the kernel is configured with CONFIG_UBSAN_TRAP, trigger a kernel panic due to out-of-bounds memory access. The root cause is a timing mismatch in setting the num_widgets count: the initial allocation uses a size derived from list_for_each iteration, but num_widgets is only updated after the array is filled, leading to potential inconsistencies during bounds checking. The patch for this vulnerability corrects the initialization sequence by setting num_widgets to the preliminary size before array population, ensuring accurate bounds checking and preventing kernel panics. This vulnerability is a memory safety issue that can cause denial of service (DoS) through kernel crashes but does not appear to allow privilege escalation or arbitrary code execution. No known exploits are reported in the wild as of the publication date (November 19, 2024).

For European organizations, this vulnerability primarily poses a risk of denial of service on Linux systems utilizing the affected ASoC DAPM audio subsystem, which is common in embedded devices, IoT appliances, and some specialized Linux distributions. A kernel panic triggered by this flaw could disrupt critical services, especially in environments relying on Linux-based infrastructure for audio processing or embedded control systems. While the impact on confidentiality and integrity is minimal, availability could be significantly affected if attackers or faulty software trigger this vulnerability. This is particularly relevant for sectors such as telecommunications, industrial control, automotive, and healthcare, where embedded Linux devices are prevalent. The absence of known exploits reduces immediate risk, but unpatched systems remain vulnerable to accidental or intentional triggering of kernel panics, potentially causing operational downtime and service interruptions.

European organizations should prioritize updating Linux kernels to versions that include the patch fixing CVE-2024-53045. Specifically, kernel maintainers and system administrators should verify that the dapm_widget_list_create function correctly initializes the num_widgets variable before populating the widgets array. For embedded and IoT devices where kernel updates may be slower, organizations should implement monitoring for kernel panics and logs indicating UBSAN warnings related to dapm_widget_list. Additionally, enabling kernel crash dump collection can aid in diagnosing and mitigating incidents. Where possible, disabling CONFIG_UBSAN_TRAP can prevent kernel panics but may allow undefined behavior to continue unchecked, so this is not a recommended long-term solution. Organizations should also review their supply chain and device inventories to identify Linux systems using the affected ASoC DAPM components and coordinate with vendors for timely patch deployment. Finally, applying strict access controls and limiting user privileges on affected systems can reduce the risk of exploitation through user-triggered audio subsystem interactions.