CVE-2022-48917

What it actually does

The snd_soc_put_volsw function accepts user-supplied volume values without adding the control's min offset before comparing against platform_max, allowing out-of-range integers (including negative values) to pass validation and reach the audio codec driver.

Why it matters to the business

Local users on affected Linux systems, including Android devices and Debian servers, can trigger unexpected audio hardware behavior that may be chained into broader kernel exploitation, increasing risk of system compromise on widely deployed kernels.

How an attack unfolds

An attacker with local access opens a sound control device, prepares a volume tuple whose raw value evades the flawed bounds check due to the missing min offset, and submits it via the ALSA mixer API to corrupt or misuse the underlying codec state.

How to fix it

Upgrade the Linux kernel to a version containing the fix: Debian 11 to 5.10.106-1 or newer, Debian 12/13 to 5.16.14-1 or newer, and Qualcomm Android kernels to the SoCVersion dated 2021-10-05 or later.

How to confirm the fix worked

Confirm the running kernel version matches or exceeds the listed fixed releases and inspect the snd_soc_put_volsw implementation to verify the +min offset is applied before the platform_max comparison.

Typical attack path

1. Obtain local unprivileged shell on target system
2. Locate ALSA mixer controls exposed by the ASoC driver
3. Craft and submit volume values that bypass the min-adjusted validation
4. Trigger hardware interaction or combine with other kernel primitives for escalation

How to detect it

Review kernel audit logs and ALSA-related syscalls for anomalous volume settings; examine dmesg or journalctl for ASoC ops warnings after the patch date.

What your security team should do

• Apply the referenced kernel updates on all Debian and Android-based systems within the next patching cycle
• Restrict untrusted local accounts from accessing ALSA mixer controls via device permissions or SELinux policies until patched
• Monitor upstream stable kernel releases for additional backports of this fix