CVE-2024-46798 is a use-after-free (UAF) vulnerability identified in the Linux kernel's ALSA System on Chip (ASoC) sound subsystem, specifically within the Dynamic Audio Power Management (DAPM) component. The flaw arises when the snd_pcm_suspend_all() function accesses a freed snd_soc_pcm_runtime object during system suspend operations. This occurs under kernel configurations that enable Kernel Address Sanitizer (KASAN) features (CONFIG_KASAN=y, CONFIG_KASAN_GENERIC=y, CONFIG_KASAN_INLINE=y, CONFIG_KASAN_VMALLOC=y) and a frame warning setting (CONFIG_FRAME_WARN=4096). The vulnerability is triggered because the snd_pcm_suspend_all() function attempts to access memory that has already been freed, leading to a use-after-free condition. The root cause is that the substream->runtime pointer is not set to NULL after its associated memory is freed (kfree), which would otherwise prevent further access. The snd_pcm_sync_stop() function includes a NULL check on substream->runtime before accessing it, but this safeguard is missing in snd_pcm_suspend_all(). This flaw can lead to kernel crashes or potentially allow an attacker to execute arbitrary code or escalate privileges by exploiting the corrupted memory state. The vulnerability was detected by KASAN during system suspend and is related to the handling of audio PCM runtime objects in the kernel's sound subsystem. The fix involves ensuring that substream->runtime is set to NULL immediately after the memory is freed to prevent use-after-free access. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a risk primarily to systems running vulnerable Linux kernel versions with the affected ASoC sound subsystem configurations. The impact includes potential system instability, crashes during suspend/resume cycles, and in worst cases, privilege escalation or arbitrary code execution if exploited by a malicious actor. This could affect servers, desktops, and embedded devices relying on Linux with sound subsystem usage, particularly in sectors like telecommunications, manufacturing, and critical infrastructure where Linux is prevalent. Disruption of audio services may also affect user experience and operational continuity in multimedia or communication systems. Additionally, exploitation could be leveraged as a foothold for further lateral movement or persistence within corporate networks. Since the vulnerability requires specific kernel configurations and relates to suspend operations, it may be more relevant for laptops, embedded devices, or specialized Linux distributions used in industrial or enterprise environments. The absence of known exploits reduces immediate risk, but the vulnerability's presence in widely used Linux kernels means organizations should prioritize patching to maintain system integrity and availability.

1. Apply the official Linux kernel patches that address CVE-2024-46798 as soon as they become available from trusted sources or Linux distribution vendors. 2. For organizations using custom or embedded Linux kernels, ensure kernel configurations are reviewed and updated to include the fix, particularly focusing on the ASoC sound subsystem and suspend/resume code paths. 3. Temporarily disable or avoid using suspend/resume features on affected systems if patching is not immediately feasible, to reduce the risk of triggering the vulnerability. 4. Implement kernel hardening techniques such as enabling KASAN in testing environments to detect similar memory corruption issues proactively. 5. Monitor system logs for KASAN or kernel warnings related to snd_pcm_suspend_all or snd_soc_pcm_runtime objects to detect potential exploitation attempts. 6. Restrict access to systems with vulnerable kernels to trusted users and networks to minimize attack surface. 7. Maintain up-to-date backups and incident response plans to quickly recover from potential exploitation impacts. 8. Engage with Linux distribution security advisories and subscribe to vulnerability notifications to stay informed about patch releases and exploitation developments.