# CVE-2022-49733: ALSA: pcm: oss: Fix race at SNDCTL_DSP_SYNC

> A race condition in the Linux kernel ALSA OSS PCM driver can lead to a NULL pointer dereference and system crash.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Mar 2025
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-49733, GHSA-73xw-qxgf-j8c4, UBUNTU-CVE-2022-49733

## What is CVE-2022-49733?

CVE-2022-49733 is a high-severity vulnerability in Linux kernel, published on 2 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49733?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49733?

Apply the vendor's patch.

## Is CVE-2022-49733 being exploited?

There is no known exploitation of CVE-2022-49733 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-49733 and fix it if it is affected.

What it is: CVE-2022-49733 is a high-severity vulnerability in Linux kernel, published on 2 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-49733 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-49733/ (Markdown: https://insights.sbomify.com/CVE-2022-49733/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49733
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49733
- OSV: https://osv.dev/vulnerability/CVE-2022-49733

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49733/
Summaries are generated and may contain mistakes; the official description above is the record.