From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-64305][MODERATE 7.0] crypto: qat - protect service table iterations with service_lock Date: Sat, 25 Jul 2026 12:12:21 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-64305 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 7 X-AL-KERNEL-ActionableScore-Lower: 4 X-AL-KERNEL-Commit: 222fa7b453b612f4407f260146d89a2ce2bc831d List-Id: CVE: CVE-2026-64305 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: crypto: qat - protect service table iterations with service_lock Commit: 222fa7b453b612f4407f260146d89a2ce2bc831d Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=222fa7b453b612f4407f260146d89a2ce2bc831d Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64305 Analysis date: Sat, 25 Jul 2026 12:12:21 -0400 ActionableScore: 7 ActionableScore lower bound: 4 Actionable bucket: Strong Important candidate / Actionable Moderate at minimum Manual review required: YES Summary: A race in the Intel QAT service_table lifecycle can allow concurrent service unregister or register during unlocked iteration, leading to list corruption or use-after-free in kernel driver callbacks and requiring manual review for DoS and possible privilege-escalation impact. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64305 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64305 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 7.0 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-2026-64305 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:H/I:H/A:H';CWE-362;*CWE-416;CWE-667;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'A race condition in the Intel QAT driver can occur because service_table is iterated without service_lock while other paths may register or unregister services under the same list. Concurrent modification can corrupt the list or leave an iterator referencing a freed service entry, which is a use after free candidate in kernel context. For the CVSS the PR:L is used for the paranoid score because some deployments may delegate QAT device or driver management to a local service account rather than full host administration. The issue is local and is not directly network reachable. Impact is at least denial of service via kernel crash, and in the worst case may allow confidentiality and integrity impact due to kernel memory corruption. YES REQUIRES MANUAL CHECK';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 6) YES LOCK INIT UAF KPANIC NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=7 ActionableScoreLower=4 ## 1. ActionableScore * Conservative score: 4 * Paranoid score: 7 * Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**:: ## 2. Signal breakdown Conservative signals: * Memory corruption, weak or indirect corruption candidate: +1. The patch explicitly mentions list corruption or use-after-free, but does not show attacker-controlled reclaim or overwrite. * Real lifetime corruption: +1. The race is between service_table traversal and service register or unregister, creating a stale lifetime window. * Reliable kernel crash / strong DoS: +1. A stale list entry or freed service object can plausibly crash the kernel during callback or field access. * Privileged kernel/device-management memory corruption path: +1. The bug is in Intel QAT driver lifecycle and error notification paths. * Hard or unreliable race / special timing required: -1. Triggering requires concurrent list traversal and service registration or unregistration. * Requires admin/root/CAP level access in typical deployments: -2. Normal triggering likely requires privileged QAT driver or service management. * Rare or hardware-specific exposure: -1. Exposure depends on systems using Intel QAT hardware and its driver stack. Paranoid additional interpretation: * Local low-privilege trigger in delegated environments: +1. Some deployments may expose QAT management through service accounts, containers, or reduced-capability operators rather than full host root. * Memory corruption, stronger UAF concern: +2. The iterator can reference a freed service entry, and the code calls service->event_hld, making callback-adjacent stale object use more serious than a plain NULL dereference. * Weak LPE concern: +1. Privilege escalation is not demonstrated, but stale object access plus callback dispatch in kernel context makes manual review warranted. * Confidentiality impact plausible: +1. Only for the paranoid score, because kernel UAF/list corruption may expose unintended kernel state if exploitable. * Integrity impact plausible: +1. Only for the paranoid score, because stale callback/object use may lead to kernel state corruption in worst case. * Availability impact realistic: +1. Kernel crash is plausible if a freed or corrupted list entry is traversed. ## 3. Reachability analysis This is local and not network reachable. In typical deployments, reliable triggering requires administrative control over QAT driver lifecycle, service registration, device reset, shutdown, restart notification, or related management paths, so the conservative interpretation is privileged local only. Namespaces or containers may matter if QAT device management is delegated to a container root, service account, or reduced-capability management process. That does not make the bug remotely reachable, but it can lower the practical privilege boundary from full host root to PR:L-like operational access. The affected path is not broadly default-exposed on all Linux systems because it depends on Intel QAT hardware and driver usage. Call-site confidence: high. The patch shows the affected list_for_each_entry iterations and shows that service->event_hld callbacks are invoked while iterating service_table. ## 4. Severity interpretation Conservatively, this is a race-dependent local driver lifecycle UAF/list-corruption bug with likely DoS impact and privileged triggering, so it is borderline Moderate and should not be auto-ranked as high solely from the UAF label. Paranoid interpretation is stronger because the stale object is used in callback-bearing service entries in kernel context. There is no demonstrated reclaim or working LPE primitive, but the combination of UAF, list corruption, callback dispatch, and possible delegated QAT management makes it an Actionable Moderate at minimum and a Strong Important candidate for manual review. ## 5. One-sentence report phrase A race in the Intel QAT service_table lifecycle can allow concurrent service unregister or register during unlocked iteration, leading to list corruption or use-after-free in kernel driver callbacks and requiring manual review for DoS and possible privilege-escalation impact. ## 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: the patch explicitly describes use-after-free or list corruption, and the affected iterator can call service callbacks through potentially stale service objects. Exploitability is not proven, but the primitive is too security-relevant to auto-close. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: crypto: qat - protect service table iterations with service_lock Commit: 222fa7b453b612f4407f260146d89a2ce2bc831d Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=222fa7b453b612f4407f260146d89a2ce2bc831d Commit description: The service_table list is protected by service_lock when entries are added or removed (in adf_service_add() and adf_service_remove()), but several functions iterate over the list without holding this lock. A concurrent adf_service_register() or adf_service_unregister() call could modify the list during traversal, leading to list corruption or a use-after-free. Fix this by holding service_lock across all list_for_each_entry() iterations of service_table in adf_dev_init(), adf_dev_start(), adf_dev_stop(), adf_dev_shutdown(), adf_dev_restarting_notify(), adf_dev_restarted_notify(), and adf_error_notifier(). The lock ordering is safe: callers of the static helpers (adf_dev_up() and adf_dev_down()) acquire state_lock before service_lock, and no event_hld callback or service_lock holder ever acquires state_lock in the reverse order. Cc: stable@vger.kernel.org Fixes: d8cba25 ("crypto: qat - Intel(R) QAT driver framework") Signed-off-by: Ahsan Atta Co-developed-by: Maksim Lukoshkov Signed-off-by: Maksim Lukoshkov Reviewed-by: Giovanni Cabiddu Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman Changed files: drivers/crypto/intel/qat/qat_common/adf_init.c 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=222fa7b453b612f4407f260146d89a2ce2bc831d ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-64305 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64305 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:H/PR:H/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7 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: 4 Paranoid ActionableScore: 7 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: YES Published priority for this report (same as in Subject): MODERATE 7.0 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).