From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98768][MODERATE 7.0] usb: typec: anx7411 - stop the IRQ before destroying the workqueue Date: Mon, 19 Oct 2026 04:55:55 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98768 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: 3 X-AL-KERNEL-ActionableScore-Lower: 2 X-AL-KERNEL-Commit: 675056e0edb49c0002ebfbc289e6c777bbf315a2 List-Id: CVE: CVE-2026-98768 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: usb: typec: anx7411 - stop the IRQ before destroying the workqueue Commit: 675056e0edb49c0002ebfbc289e6c777bbf315a2 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=675056e0edb49c0002ebfbc289e6c777bbf315a2 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98768 Analysis date: Mon, 19 Oct 2026 04:55:55 -0400 ActionableScore: 3 ActionableScore lower bound: 2 Actionable bucket: Borderline / manual review recommended Manual review required: YES Summary: A devm managed IRQ can queue anx7411 work while driver removal destroys its workqueue, creating a narrow teardown use-after-free race that may crash the kernel but has no demonstrated controlled corruption or privilege escalation primitive. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98768 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98768 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-2026-98768 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98768 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=2 LEGACY=MODERATE_KPANIC RESULT=SAME V39_AEGIS_ONE_STEP_UP=MODERATE->MODERATE_KPANIC (final reconciliation agrees; DECISION: both MODERATE_KPANIC) 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-672;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'A lifecycle race in the anx7411 Type C driver allows the devm managed IRQ to queue plat work while anx7411_i2c_remove() is cancelling work and destroying the associated workqueue. A late interrupt can therefore submit work through a stale workqueue pointer, creating a potential use-after-free that may corrupt workqueue state or crash the kernel. Reliable triggering requires an IRQ to occur inside the narrow driver teardown window, so the attack complexity is high. For the CVSS the PR:L value is used for the paranoid score because a locally constrained user may be able to influence Type C activity or operate through delegated device management while teardown is initiated by another system component. The normal administrative unbind path instead supports PR:H for the base score. The issue is not network reachable, although a connected Type C or USB PD device may influence interrupt timing. Impact is at least a local denial of service via kernel crash and in the worst case may allow confidentiality or integrity impact due to potential use-after-free memory corruption. YES REQUIRES MANUAL CHECK. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 7 and the production ActionableScore returned 3 with recommendation Borderline / manual review recommended. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage LOW to MODERATE_KPANIC because the manual review requirement was applied. ActionableScore thresholds stage MODERATE_KPANIC to MODERATE because the ActionableScore threshold rule was applied. final reconciliation stage MODERATE to MODERATE_KPANIC because the cross model evidence reconciliation rule was applied. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK and DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 and V39_AEGIS_ONE_STEP_UP and MANUAL_REVIEW_REQUIRED. The independent weaker Aegis shadow evaluated CVSS 2.1 and ActionableScore 2 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 3) MAYBE USB SIMPLEFIX LINUS INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 KPANIC V39_AEGIS_ONE_STEP_UP MANUAL_REVIEW_REQUIRED - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=3 ActionableScoreLower=2 PrimitiveClass=CLASS_B RealUAF=YES HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=NO ManualReview=RECOMMENDED AutoDowngradeAllowed=YES RequiresHostUID0=UNKNOWN AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO ## 1. ActionableScore * Raw conservative score: 2 * Conservative score: 2 * Raw paranoid score: 3 * Paranoid score: 3 * No floor or cap was applied. * Final recommended bucket: **Borderline / manual review recommended**:: ## 2. Signal breakdown Conservative signals: * +2 Real UAF or lifetime violation. The devm-managed IRQ can call `queue_work()` while `plat->workqueue` is being destroyed, potentially consuming the workqueue after its lifetime has ended. * +1 Plausible kernel crash. Submission through a destroyed workqueue can produce an invalid access, workqueue corruption, warning, or kernel fault. * -1 Narrow one-shot teardown race. The IRQ must arrive during the limited interval in `anx7411_i2c_remove()` where the queue is being cancelled or destroyed. Paranoid addition: * +1 Firmware-mediated external influence. Type C or USB PD activity can plausibly influence controller interrupts, although the supplied evidence does not prove that an external device can independently initiate the required driver teardown. Not awarded: * No controlled reclaim, attacker-shaped replacement object, arbitrary write, callback control, disclosure, or repeated lifetime mutation is established. * Structured stale-object leverage is not awarded. The stale operation is limited to work submission during driver teardown, and attacker control over reused workqueue contents is not shown. * No additional availability point is awarded for the same possible crash. * No authorization bypass, shared-backing write, checksum corruption, B5-R retry-accumulated OOB write, or cross-boundary state corruption exists here. * Confidentiality and integrity bonuses are not awarded merely because a workqueue UAF could theoretically corrupt reused memory. ## 3. Reachability analysis The complete trigger has two stages: driver removal and an IRQ arriving during workqueue destruction. Deliberate driver unbind or module removal normally involves host device-management authority, but the supplied material does not establish whether every affected teardown path requires an attacker with host-admin powers. Therefore `HostAdminRequired=UNKNOWN` rather than YES or NO. A connected Type C or USB PD device may influence interrupt generation, but it cannot be assumed to control I2C driver removal. The likely attacker model is therefore compound: a peripheral or local actor influences IRQ timing while another system component initiates teardown. No namespace-scoped trigger, network path, or ordinary unprivileged complete trigger is established. The race is difficult to drive reliably because it is tied to a narrow, usually one-time removal interval. ## 4. Primitive and severity interpretation The exact primitive is an asynchronous post-teardown submission through a potentially stale `struct workqueue_struct` pointer. This is a real Class B lifetime violation because the IRQ remains registered while the object it references is being destroyed. The workqueue is an active structured object, but the vulnerable use is constrained to cleanup. There is no concrete second `put`, `free`, or refcount mutation on the same dangling reference. The patch does not establish attacker-controlled reclaim, useful post-free contents, an arbitrary kernel write, or privilege escalation. The demonstrated defect supports a possible crash or workqueue-state corruption. Stronger exploitation remains theoretical and lacks a concrete leverage mechanism. Consequently, this is not an Important candidate, and automatic downgrade remains permissible after recommended human confirmation of the actual `destroy_workqueue()` race window. ## 5. One-sentence report phrase A devm managed IRQ can queue anx7411 work while driver removal destroys its workqueue, creating a narrow teardown use-after-free race that may crash the kernel but has no demonstrated controlled corruption or privilege escalation primitive. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED Confirm whether the IRQ can execute after `destroy_workqueue()` has completed and whether any non-administrative or externally controlled path can initiate the complete teardown and interrupt sequence. ## 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: usb: typec: anx7411 - stop the IRQ before destroying the workqueue Commit: 675056e0edb49c0002ebfbc289e6c777bbf315a2 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=675056e0edb49c0002ebfbc289e6c777bbf315a2 Commit description: The IRQ is devm-managed, so it can still queue plat->work while remove() is tearing the queue down. Disable it first. Fixes: fe6d8a9 ("usb: typec: anx7411: Add Analogix PD ANX7411 support") Cc: stable Signed-off-by: Linkai Gong Reviewed-by: Heikki Krogerus Link: https://patch.msgid.link/20260910011150.2966843-1-gonglinkai@kylinos.cn Signed-off-by: Greg Kroah-Hartman Changed files: drivers/usb/typec/anx7411.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=675056e0edb49c0002ebfbc289e6c777bbf315a2 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98768 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98768 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:N/I:N/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: 2 Paranoid ActionableScore: 3 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).