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

crypto: qat - remove unused character device and IOCTLs

The QAT driver exposes a character device (qat_adf_ctl) with IOCTLs
for device configuration, start, stop, status query and enumeration.
These IOCTLs are not part of any public uAPI header and have no known
in-tree or out-of-tree users. Device lifecycle is already managed via
sysfs.

The ioctl interface also increases the attack surface and is the
subject of a number of bug reports.

Remove the character device, the IOCTL definitions, and the related
data structures (adf_dev_status_info, adf_user_cfg_key_val,
adf_user_cfg_section, adf_user_cfg_ctl_data). Drop the now-unused
adf_cfg_user.h header and strip adf_ctl_drv.c down to the minimal
module_init/module_exit hooks for workqueue, AER, and crypto/compression
algorithm registration.

Clean up leftover dead code that was only reachable from the removed
IOCTL paths: adf_cfg_del_all(), adf_devmgr_verify_id(),
adf_devmgr_get_num_dev(), adf_devmgr_get_dev_by_id(),
adf_get_vf_real_id() and the unused ADF_CFG macros.

Additionally, drop the entry associated to QAT IOCTLs in
ioctl-number.rst.
Published: 2026-07-25
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: Potential Vulnerable IOCTL Interface Exposure
Action: Apply Patch
AI Analysis

Impact

The QAT driver in the Linux kernel exposed a legacy character device (qat_adf_ctl) with several undocumented IOCTLs that were not part of the public API and had no known users. These unused interfaces expanded the kernel’s attack surface and introduced code paths that were only reachable via those IOCTLs. The vulnerability is mitigated by removing the character device, the IOCTL definitions, and associated structures, thereby eliminating the exposed functionality and associated dead code.

Affected Systems

The issue applies to any Linux kernel build that includes the QAT driver before the patches removing the legacy device and IOCTLs. Systems running kernels that load the qat module and expose the /dev/qat_adf_ctl device are affected until the code changes are applied.

Risk and Exploitability

The EPSS score is below 1% and the vulnerability is not listed in CISA KEV, indicating a low empirical exploitation probability at present. The CVSS score of 7.8 classifies the vulnerability as high severity. The IOCTL interface has no documented legitimate users and is not exposed via public APIs, so typical unprivileged usage is unlikely to trigger it. However, a process with root or sufficient kernel privileges could invoke these legacy IOCTLs if the obsolete device remains on a system not yet updated.

Generated by OpenCVE AI on October 20, 2026 at 09:57 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade the kernel to a version that includes the QAT driver changes removing the unused character device and IOCTLs.
  • If the system relies on the qat module but cannot apply the patch immediately, disable the module by removing it with "modprobe -r qat" or by preventing its automatic loading via module configuration.
  • Monitor system logs for any attempts to access or interact with the obsolete /dev/qat_adf_ctl device or related ioctl operations.

Generated by OpenCVE AI on October 20, 2026 at 09:57 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4700-1 linux-6.1 security update
Debian DLA Debian DLA DLA-4717-1 linux security update
Ubuntu USN Ubuntu USN USN-8726-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8727-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8760-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-2 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8781-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-3 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8800-1 Linux kernel (NVIDIA BaseOS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8760-2 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-3 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8875-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8877-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8878-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8879-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8875-2 Linux kernel (NVIDIA) vulnerabilities
History

Mon, 19 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-489

Fri, 16 Oct 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 30 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-749
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 27 Jul 2026 05:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Sat, 25 Jul 2026 10:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: crypto: qat - remove unused character device and IOCTLs The QAT driver exposes a character device (qat_adf_ctl) with IOCTLs for device configuration, start, stop, status query and enumeration. These IOCTLs are not part of any public uAPI header and have no known in-tree or out-of-tree users. Device lifecycle is already managed via sysfs. The ioctl interface also increases the attack surface and is the subject of a number of bug reports. Remove the character device, the IOCTL definitions, and the related data structures (adf_dev_status_info, adf_user_cfg_key_val, adf_user_cfg_section, adf_user_cfg_ctl_data). Drop the now-unused adf_cfg_user.h header and strip adf_ctl_drv.c down to the minimal module_init/module_exit hooks for workqueue, AER, and crypto/compression algorithm registration. Clean up leftover dead code that was only reachable from the removed IOCTL paths: adf_cfg_del_all(), adf_devmgr_verify_id(), adf_devmgr_get_num_dev(), adf_devmgr_get_dev_by_id(), adf_get_vf_real_id() and the unused ADF_CFG macros. Additionally, drop the entry associated to QAT IOCTLs in ioctl-number.rst.
Title crypto: qat - remove unused character device and IOCTLs
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T20:48:38.158Z

Reserved: 2026-07-19T15:36:31.794Z

Link: CVE-2026-64529

cve-icon Vulnrichment

Updated: 2026-10-16T15:41:42.541Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-07-25T10:17:39.317

Modified: 2026-11-03T18:15:39.353

Link: CVE-2026-64529

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-25T00:00:00Z

Links: CVE-2026-64529 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-20T10:00:14Z

Weaknesses
  • CWE-489

    Active Debug Code

  • CWE-749

    Exposed Dangerous Method or Function