From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64529][MODERATE REGULAR] crypto: qat - remove unused character device and IOCTLs [ Upstream Date: Sat, 25 Jul 2026 13:23:16 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64529 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 4 X-AL-KERNEL-ActionableScore-Lower: 2 X-AL-KERNEL-Commit: 071590a44cbc38483fceb1ab943363ec26868e1b List-Id: CVE: CVE-2026-64529 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: crypto: qat - remove unused character device and IOCTLs [ Upstream Commit: 071590a44cbc38483fceb1ab943363ec26868e1b Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=071590a44cbc38483fceb1ab943363ec26868e1b Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64529 Analysis date: Sat, 25 Jul 2026 13:23:16 -0400 ActionableScore: 4 ActionableScore lower bound: 2 Actionable bucket: Borderline / manual review recommended Manual review required: YES Summary: The QAT driver removed an undocumented local qat_adf_ctl IOCTL control interface for device configuration and lifecycle management, reducing a privileged driver attack surface that was referenced by multiple bug reports but does not show a concrete memory corruption primitive in the provided patch. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64529 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64529 The original announcement does not normally provide a security severity estimate, CVSS assessment, or enough information to determine whether the reported kernel bug represents a practically relevant security issue. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. It combines an autonomous classifier with LLM-assisted technical analysis and a separate ActionableScore mechanism. The purpose of this report is to prioritize Linux kernel CVEs before manual review, identify cases that require prompt investigation, and support automatic closure of issues that are unlikely to have meaningful security impact. Published priority for this report: MODERATE REGULAR Manual review required: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-64529 MODERATE CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';CWE-284;CWE-749;CWE-269;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L';BEST CVSS score: '5.8';DESCR 'The QAT driver exposed an unused qat_adf_ctl character device with undocumented IOCTLs for device configuration, start, stop, status query, and enumeration. This interface was not part of a public uAPI and had no known in tree or out of tree users, but it increased the local kernel attack surface and was referenced by several bug reports. For the CVSS the PR:L is used for the paranoid score because a local process with access to the qat_adf_ctl device node, a delegated service account, or reduced capability root may be able to reach the IOCTL paths without full host administrator privileges. The issue is not network reachable and requires local access to the affected device interface. Impact is primarily local denial of service or control plane policy impact, with limited confidentiality or integrity impact kept only for manual review sensitivity because no concrete UAF, OOB write, or arbitrary write primitive is visible in the provided diff.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 3) YES INIT HARDWARE INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5 NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=4 ActionableScoreLower=2 ## 1. ActionableScore * Conservative score: 2 * Paranoid score: 4 * Final recommended bucket: **Borderline / manual review recommended**:: ## 2. Signal breakdown Conservative signals: * Requires admin/root/CAP in typical deployments: -2. Access to QAT device lifecycle/configuration is usually restricted to root or privileged service context. * Availability impact realistic: +1. The removed IOCTLs could start, stop, configure, query, and enumerate QAT devices, so misuse or bugs in these paths could affect local accelerator availability. * Local device management attack surface: +1. The interface exposed a local character device control plane into a privileged hardware driver, but the supplied patch does not show a concrete corruption primitive. Conservative total: 2. Paranoid additional signals: * Local reduced privilege trigger concern: +1. If qat_adf_ctl permissions were delegated to a service account, container root, or non full host root operator, the IOCTL paths may be reachable without full administrative control. * Weak indirect corruption candidate: +1. The removed IOCTLs accepted user controlled configuration/status structures and reached device lookup/configuration deletion paths, but the patch does not demonstrate UAF, OOB write, double free, or arbitrary write. * Manual review sensitivity due to multiple bug reports: included in the paranoid interpretation. The commit says the interface was the subject of a number of bug reports and removes the whole user interface instead of fixing one narrow condition. Paranoid total: 4. Not awarded: * No remote/network trigger. * No strong memory corruption primitive shown. * No demonstrated LPE chain. * No confidentiality impact proven. * No Dirty Pipe like or page cache primitive. * No generic high control API bonus, because this is a device control IOCTL interface and the patch does not show attacker control over allocator layout, object lifetime, callbacks, or refcounts. ## 3. Reachability analysis The affected path is a local QAT character device interface, not a network reachable path. In typical deployments, QAT device configuration and lifecycle management are privileged operations, so the conservative interpretation treats this as requiring admin level access. A paranoid interpretation is still warranted because real systems sometimes delegate accelerator control to service accounts, containerized workloads, or reduced capability root users, which can make PR closer to local low privilege rather than full host root. The path is only relevant on systems with Intel QAT driver support and the qat_adf_ctl device exposed. This is not a universal default kernel attack surface, but it is security relevant on QAT enabled hosts. ## 4. Severity interpretation This behaves more like a borderline actionable Moderate than an Important class issue based on the supplied patch alone. The patch removes an undocumented local IOCTL attack surface and references multiple bug reports, which justifies manual review. However, the diff does not disclose a concrete UAF, OOB write, double free, type confusion, refcount bug, arbitrary write, or demonstrated privilege escalation path. Theoretical risk is higher than an ordinary cleanup because the removed interface controlled device configuration and lifecycle in a privileged kernel driver. Realistic exploitation evidence is not present in the supplied material, so the score should not be raised into Strong Important without reviewing the linked reports. ## 5. One-sentence report phrase The QAT driver removed an undocumented local qat_adf_ctl IOCTL control interface for device configuration and lifecycle management, reducing a privileged driver attack surface that was referenced by multiple bug reports but does not show a concrete memory corruption primitive in the provided patch. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED Manual review is recommended because the patch removes an entire undocumented IOCTL interface and cites multiple bug reports, but the supplied diff alone does not justify treating it as confirmed memory corruption or LPE. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: crypto: qat - remove unused character device and IOCTLs [ Upstream Commit: 071590a44cbc38483fceb1ab943363ec26868e1b Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=071590a44cbc38483fceb1ab943363ec26868e1b Changed files: drivers/crypto/qat/qat_common/adf_cfg_common.h drivers/crypto/qat/qat_common/adf_cfg_user.h drivers/crypto/qat/qat_common/adf_common_drv.h Diff excerpt: Not included in this email. See the upstream URL for the full patch. Full patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=071590a44cbc38483fceb1ab943363ec26868e1b ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64529 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64529 The original CVE announcement normally does not include a security-level estimate. In particular, it may not contain a CVSS assessment, an impact level, or enough information to determine whether the reported bug is a practically relevant security issue. One purpose of this parallel CVE list is to provide that missing technical and prioritization information. The original goal of the AL-KERNEL project was to prioritize Linux kernel CVE analysis automatically before manual review. The system can also help identify non-security issues that may be suitable for automatic closure. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. The first analysis stage combines an autonomous classifier with additional LLM-based analysis. The autonomous classifier runs locally on a CPU and is based on a backpropagation neural network. Together, these mechanisms produce a technical vulnerability description, identify likely weakness types, estimate CVSS severity, and provide input for ActionableScore. Two CVSS estimates are retained because incomplete kernel vulnerability information often permits more than one defensible interpretation: Conservative CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS score: 5.8 The conservative vector represents a lower-impact interpretation. The Best/paranoid vector intentionally represents a plausible upper-bound interpretation and should not automatically be treated as demonstrated real-world impact. CVSS may also need to be adjusted for a particular Linux deployment, because actual reachability, privileges, enabled kernel configuration, hardware, namespaces, exposed device nodes, and other environmental conditions can differ significantly between systems. A separate ActionableScore mechanism evaluates practical remediation urgency. Its analysis may include reachability, attack prerequisites, subsystem exposure, memory-corruption characteristics, denial-of-service reliability, and possible confidentiality, integrity, or privilege-escalation impact. Conservative ActionableScore: 2 Paranoid ActionableScore: 4 The final base severity is taken directly from the second tab-separated field of the AL-KERNEL classification result. ActionableScore does not replace or independently override that final AL-KERNEL decision, and if ActionableScore adjusted impact level of ALKERNEL, then you would see self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7. For an AL-KERNEL result of MODERATE, this report uses the following additional presentation split: ActionableScore below 5 -> MODERATE REGULAR ActionableScore 5 or more -> MODERATE 7.0 The distinction between MODERATE REGULAR and MODERATE 7.0 makes it possible to identify Moderate issues that should receive manual analysis and fixes before lower-priority MODERATE REGULAR issues. In many cases, MODERATE REGULAR fixes may wait for a later rebase or routine update. There is one override in which MODERATE REGULAR becomes MODERATE 7.0 even when the ActionableScore is below 5. When the AL-KERNEL result contains the KPANIC flag, a MODERATE result is always presented as MODERATE 7.0. The KPANIC flag selected with few regexps without usage of AI at all, so it helps to detect cases when Kernel Crash happens and similar (to filter False-Negative results from the LLM usage). KPANIC indicates that a reliable kernel crash, kernel panic, or similarly serious kernel availability impact was identified by the classification workflow. AL-KERNEL base severity for this report: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR These results are intended to support engineering triage. They are machine-generated estimates, and cases marked for manual review should be validated by a human security engineer before final disposition. For more info read docs linked from here: https://kernelcve.org/ (and you can submit you own patch there to generate such a report for non-existant CVE-id yet). Note that in many cases this AI tool selects higher severity, than real is (means you can expect Importants instead of Moderate 7.0 or Moderates 7.0 instead of regular Moderates). If you see such cases, please use reply email interface to add additional manual analyses info to this particular CVE. And please, please, let me know when you see Lows instead of Importants or Important instead of Low (because particular for such cases I need to tune this AI tool to make it better for this one and next similar). My contact email for such notifications is alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).