---
id: CVE-2026-90323
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ublk: validate auto buf reg before taking uring_cmd

  With UBLK_F_AUTO_BUF_REG, invalid sqe->addr can fail after
  ublk_fill_io_cmd() has set UBLK_IO_FLAG_ACTIVE
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ublk: validate auto buf reg before taking uring_cmd

  With UBLK_F_AUTO_BUF_REG, invalid sqe->addr can fail after
  ublk_fill_io_cmd() has set UBLK_IO_FLAG_ACTIVE. The urin…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 52460dda3a775a73f226312b43c0a0211e8665ea <
    653d22269a8b83b491f7f186a5d7872f14e6ddca
  - >-
    Linux >= 52460dda3a775a73f226312b43c0a0211e8665ea <
    ca5a01eee34c7cbe0f531a613b0292a3ad1a419b
  - Linux 6.17
published: '2026-09-17'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T17:17:30.307'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90323'
references:
  - url: 'https://git.kernel.org/stable/c/653d22269a8b83b491f7f186a5d7872f14e6ddca'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ca5a01eee34c7cbe0f531a613b0292a3ad1a419b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-17T16:21:47.822Z'
epss: 0.00198
epssPercentile: 0.08437
---

## Overview

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

ublk: validate auto buf reg before taking uring_cmd

With UBLK_F_AUTO_BUF_REG, invalid sqe->addr can fail after
ublk_fill_io_cmd() has set UBLK_IO_FLAG_ACTIVE. The uring_cmd is
completed while the tag stays active, which can hang teardown.

Split validation from buffer apply so the check has no side effects,
then take the uring_cmd and store the already-validated buffer. Apply
the same order in FETCH so io->buf is not written before __ublk_fetch()
state checks.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.