KEVWire

Security intelligence, with context.

Response snapshot Oct 28, 2026, 20:06 UTC

Back to the wire
Permalink
VulnerabilityCVE-2023-53713

Linux kernel: arm64: sme: Use STR P to clear FFR context field in streaming SVE mode

In the Linux kernel, the following vulnerability has been resolved: arm64: sme: Use STR P to clear FFR context field in streaming SVE mode The FFR is a predicate register which can vary between 16 and 256 bits in size depending upon the configured vector length.

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2023-53713 (opens a new tab)

What happened

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

arm64: sme: Use STR P to clear FFR context field in streaming SVE mode

The FFR is a predicate register which can vary between 16 and 256 bits in size depending upon the configured vector length. When saving the SVE state in streaming SVE mode, the FFR register is inaccessible and so commit 9f5848665788 ("arm64/sve: Make access to FFR optional") simply clears the FFR field of the in-memory context structure.

Unfortunately, it achieves this using an unconditional 8-byte store and so if the SME vector length is anything other than 64 bytes in size we will either fail to clear the entire field or, worse, we will corrupt memory immediately following the structure. This has led to intermittent kfence splats in CI [1] and can trigger kmalloc Redzone corruption messages when running the 'fp-stress' kselftest:

Continue reading

| ============================================================================= | BUG kmalloc-1k (Not tainted): kmalloc Redzone overwritten | ----------------------------------------------------------------------------- | | 0xffff000809bf1e22-0xffff000809bf1e27 @offset=7714. First byte 0x0 instead of 0xcc | Allocated in do_sme_acc+0x9c/0x220 age=2613 cpu=1 pid=531 | __kmalloc+0x8c/0xcc | do_sme_acc+0x9c/0x220 | ...

Replace the 8-byte store with a store of a predicate register which has been zero-initialised with PFALSE, ensuring that the entire field is cleared in memory.

[1] https://lore.kernel.org/r/CA+G9fYtU7HsV0R0dp4XEH5xXHSJFw8KyDf5VQrLLfMxWfxQkag@mail.gmail.com

Scores and how they were measured

CVSS base severity

7.8

Version 3.1As of

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2023-53713 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 28). Linux kernel: arm64: sme: Use STR P to clear FFR context field in streaming SVE mode (CVE-2023-53713). https://kevwire.com/record/CVE-2023-53713

MLA

"Linux kernel: arm64: sme: Use STR P to clear FFR context field in streaming SVE mode (CVE-2023-53713)." KEVWire, 28 Oct. 2026, kevwire.com/record/CVE-2023-53713.

Chicago

KEVWire. "Linux kernel: arm64: sme: Use STR P to clear FFR context field in streaming SVE mode (CVE-2023-53713)." Last modified October 28, 2026. https://kevwire.com/record/CVE-2023-53713.

Evidence summary (plain text)

Linux kernel: arm64: sme: Use STR P to clear FFR context field in streaming SVE mode (Oct 22, 2025).
In the Linux kernel, the following vulnerability has been resolved:

arm64: sme: Use STR P to clear FFR context field in streaming SVE mode

The FFR is a predicate register which can vary between 16 and 256 bits
in size depending upon the configured vector length. When saving the
SVE state in streaming SVE mode, the FFR register is inaccessible and
so commit 9f5848665788 ("arm64/sve: Make access to FFR optional") simply
clears the FFR field of the in-memory context structure.
CVSS 7.8 (version 3.1; evidence as of Oct 28, 2026; https://nvd.nist.gov/vuln/detail/CVE-2023-53713).
Sources:
NVD CVE-2023-53713: https://nvd.nist.gov/vuln/detail/CVE-2023-53713
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-28T18:31:08.168Z&lastModEndDate=2026-10-28T20:05:58.019Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-28T17:55:58.678Z&lastModEndDate=2026-10-28T19:30:56.852Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2023-53713.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 28, 2026, 20:05 UTC. Ingestion is not an independent editorial investigation.

NVD status: Deferred. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

Your account

Email alerts

Email alerts are coming as part of KEVWire Premium: join the waitlist. To follow your stack today, use its RSS feed, which honors your filters, or connect an AI agent through the API.

Suggest an improvement

Ideas, missing sources, corrections, and bugs are all welcome. No account needed. Suggestions are reviewed by a person before anything changes.

Record details

Record detail