---
id: "CVE-2026-98961"
kind: "vulnerability"
aliases: ["CVE-2026-98961"]
title: "Linux kernel btrfs: io_uring encoded read leaves inode and extent locked"
severity: "unknown"
cvss: null
epss: 0.00206
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["btrfs", "infrastructure", "kernel", "linux", "self-hosted"]
not_affected_if: ["no-btrfs"]
published_at: "2026-10-23T13:17:17+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98961", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-98961", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux kernel btrfs: io_uring encoded read leaves inode and extent locked

In the btrfs filesystem, a failed io_uring encoded read could return without releasing the inode and extent locks, or skip unlocking on a pages-array allocation failure. The sources do not say what an attacker gains beyond a stalled or deadlocked file operation.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- Update the Linux kernel to a release that includes the upstream btrfs commit resolving this CVE; the sources do not name a version.

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98961
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-98961

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

btrfs: unlock inode and extent in caller when io_uring read extent fails

btrfs_uring_read_extent() runs only after btrfs_encoded_read() has taken
the inode shared lock and the extent lock.  On failure it used to unlock
in out_fail, and a pages-array allocation failure returned -ENOMEM
without unlocking at all.

Unlock in the caller instead on all failure returns, matching the
copy_to_user() error path.  The deferred -EIOCBQUEUED path still unlocks
in btrfs_uring_read_finished().

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_