CVE-2026-89941

Kernel use-after-free via non-RCU DMA fence release

Published Sep 16, 2026 · Updated Sep 16, 2026

Use-after-free in the IIO buffer subsystem in Linux 6.11 allows attackers to access freed kernel memory during DMA fence release. The iio_buffer_dma_fence_release callback passes iio_dma_fence directly to kfree(), although custom dma_fence release handlers require RCU-safe reclamation. Reachability requires the IIO DMABUF interface and a fence release concurrent with an RCU reader; no further consequence is publicly documented.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the IIO buffer subsystem in Linux 6.11 allows attackers to access freed kernel memory during DMA fence release. The iio_buffer_dma_fence_release callback passes iio_dma_fence directly to kfree(), although custom dma_fence release handlers require RCU-safe reclamation. Reachability requires the IIO DMABUF interface and a fence release concurrent with an RCU reader; no further consequence is publicly documented.

The record

CVE
CVE-2026-89941
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <06a9460b8b792e109cbc934a856d02e5cff217ef
  2. Affected versionversion=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <11cef99491117d4264603df159c4ff5f3845a059
  3. Affected versionversion=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <311595dc0b5621f74d8eb4dc38ef4efcdfe7e769
  4. Affected versionversion=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <8662e56c31cf23b61ca3d11b516efb94c35b8026
  5. Affected versionversion=6.11

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <06a9460b8b792e109cbc934a856d02e5cff217ef; version=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <11cef99491117d4264603df159c4ff5f3845a059; version=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <311595dc0b5621f74d8eb4dc38ef4efcdfe7e769; version=3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f <8662e56c31cf23b61ca3d11b516efb94c35b8026; version=6.11

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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