A flaw in the ALSA us122l driver in the Linux kernel allows a process that can open the hardware–dependent node with read‑write permissions to create a memory mapping that is initially marked read‑only but still retains the writable flag. The driver does not clear that writable permission after rejecting a writable mapping request. This oversight enables the process to later invoke mprotect and upgrade the mapping to writable, giving it the ability to write arbitrary data to memory regions that should be protected. Such kernel buffer corruption can potentially lead to privilege escalation or other compromise scenarios.

The vulnerability is present in all Linux kernel builds that include the ALSA us122l driver. No specific kernel versions are listed in the supplied data, so users should verify whether their kernel contains this driver and apply updates accordingly.

The CVSS score is 7.0, indicating a high severity vulnerability. The exploit requires a local process that has write access to the hwdep node, typically a privileged user. The EPSS score is <1%, indicating that exploitation is unlikely. The CVE is not listed in CISA’s KEV catalog, implying that exploitation has not been reported widely. The flaw allows the process to upgrade the mapping to writable, providing kernel write privileges. Based on the description, it is inferred that the impact of this exploit, such as privilege escalation, depends on the system configuration and the attacker’s capabilities.