ublk: validate auto buf reg before taking uring_cmd (CVE-2026-90323) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90323

ublk: validate auto buf reg before taking uring_cmd

Answer in brief

CVE-2026-90323 records a Unknown severity vulnerability in ublk: validate auto buf reg before taking uring_cmd. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=52460dda3a775a73f226312b43c0a0211e8665ea <653d22269a8b83b491f7f186a5d7872f14e6ddca \|\| >=52460dda3a775a73f226312b43c0a0211e8665ea <ca5a01eee34c7cbe0f531a613b0292a3ad1a419b	653d22269a8b83b491f7f186a5d7872f14e6ddca, ca5a01eee34c7cbe0f531a613b0292a3ad1a419b
Linux/Linuxgeneric	6.17	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 653d22269a8b83b491f7f186a5d7872f14e6ddca if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.