# CVE-2026-98314: ALSA: pcm: set timer->private_data before registering the PCM timer

> A race condition in the Linux kernel ALSA PCM timer allows local attackers to trigger a NULL pointer dereference and cause a system crash.

- **Severity:** Not scored
- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106380, BELL-CVE-2026-98314, DEBIAN-CVE-2026-98314, GHSA-f958-2rwj-98rc, UBUNTU-CVE-2026-98314

## What is CVE-2026-98314?

CVE-2026-98314 is a vulnerability in Linux, published on 6 Oct 2026. 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: set timer->private_data before registering the PCM timer

snd_pcm_timer_init() calls snd_device_register() to link the new
struct snd_timer into the global timer list while it still carries
hw.c_resolution = snd_pcm_timer_resolution (and hw.start/hw.stop),
and only afterwards sets timer->private_data = substream.

Once the timer is on the list under register_mutex, a concurrent
reader can already reach it through the same mutex and invoke these
callbacks. /proc/asound/timers does this via c_resolution(), and
snd_timer_open()+snd_timer_start() reach start()/stop() the same way.
All three dereference timer->private_data, which for this brief
window is NULL, giving a NULL-pointer dereference:

  substream = timer->private_data;
  return substream->runtime ? ...   // substream is NULL

Move the private_data/private_free assignment before
snd_device_register() so the timer is never visible on the list
without its private_data set. On the snd_device_register() failure
path, private_free() (snd_pcm_timer_free()) can now run, but it only
does substream->timer = NULL, which is already NULL at that point
since substream->timer is set to the new timer just once, after a
successful registration -- so the failure path stays safe.

## Which versions are affected by CVE-2026-98314?


## How do I fix CVE-2026-98314?

Apply the vendor's patch.

## Is CVE-2026-98314 being exploited?

There is no known exploitation of CVE-2026-98314 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98314 and fix it if it is affected.

What it is: CVE-2026-98314 is a vulnerability in Linux, published on 6 Oct 2026. 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-2026-98314 in the wild and no public exploit code.

Affected product: Linux. 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-2026-98314/ (Markdown: https://insights.sbomify.com/CVE-2026-98314/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98314
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98314
- OSV: https://osv.dev/vulnerability/CVE-2026-98314

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98314/
Summaries are generated and may contain mistakes; the official description above is the record.