From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98336][MODERATE REGULAR] wifi: mac80211: don't offload TC setup on AP_VLAN interfaces [ Upstream Date: Sat, 10 Oct 2026 07:11:59 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98336 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: 2 X-AL-KERNEL-ActionableScore-Lower: 1 X-AL-KERNEL-Commit: 790221efbfece13a2347563b3785aaca48f192e2 List-Id: CVE: CVE-2026-98336 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: wifi: mac80211: don't offload TC setup on AP_VLAN interfaces [ Upstream Commit: 790221efbfece13a2347563b3785aaca48f192e2 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=790221efbfece13a2347563b3785aaca48f192e2 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98336 Analysis date: Sat, 10 Oct 2026 07:11:59 -0400 ActionableScore: 2 ActionableScore lower bound: 1 Actionable bucket: Ordinary Moderate Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98336 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98336 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: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-98336 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98336 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT MODERATE AEGIS_AS=0 LEGACY=MODERATE RESULT=SAME (legacy and Aegis reconciliation agree; DECISION: both MODERATE) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-20;CWE-754;CWE-670;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '5.5';DESCR 'mac80211 can incorrectly forward a TC offload setup request for a purely virtual AP_VLAN interface to a wireless driver. The driver may receive a vif context that does not represent a hardware backed interface and that it was not designed to process. The demonstrated primitive is an invalid driver callback context. The supplied code does not establish a UAF, an OOB access, an information leak, or a controlled write. The issue is locally triggered through TC control plane configuration and is not directly reachable by sending network packets. For the CVSS the PR:L value is used for the paranoid score because CAP_NET_ADMIN may be delegated to a container, network service, or restricted administrative account even though host level configuration normally requires PR:H. The base impact is limited network availability degradation. The paranoid impact allows A:H because behavior depends on the driver and an unexpected vif type could potentially cause a more serious network or kernel failure. Driver specific consequences and the syzbot report require manual confirmation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) MAYBE REMOTE DANGER SIMPLEFIX SYZBOT DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=2 ActionableScoreLower=1 PrimitiveClass=CLASS_C RealUAF=NO 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: 1 * Conservative score: 1 * Raw paranoid score: 2 * Paranoid score: 2 * No floor or cap applied. * Final recommended bucket: **Ordinary Moderate**:: 2. Signal breakdown Conservative signals: * +1 Limited availability impact. A TC offload request for a purely virtual AP_VLAN interface is incorrectly dispatched to a hardware driver, potentially causing TC setup failure or disruption instead of software fallback. * 0 privilege penalty. The complete capability and namespace requirements are unresolved, so host-administrator privilege cannot be assumed. * Raw conservative total: 1. Paranoid signals: * +1 Limited availability impact from the failed or invalid TC offload operation. * +1 Weak indirect invalid-state candidate. The driver receives a valid mac80211 object in a semantic context it is not expected to process because AP_VLAN has no corresponding hardware-backed interface. * Raw paranoid total: 2. Not awarded: * No UAF, OOB access, write, refcount corruption, or stale lifetime operation is established. * No reliable kernel crash is demonstrated by the supplied commit text. * No additional availability point is awarded for a hypothetical driver crash. * No controlled reclaim, arbitrary write, information disclosure, privilege escalation, or security-boundary bypass is established. * No remote-reachability point is awarded because packet traffic does not directly invoke TC control-plane configuration. * No local-unprivileged point is awarded because the complete CAP_NET_ADMIN and wireless-device ownership chain is unresolved. * B5-R does not apply because there is no confirmed retry-accumulated heap OOB write or later consumption of corrupted state. * B3-PENDING does not apply because no shared-backing write is present. * B4-PENDING does not apply because the new AP_VLAN type check is compatibility validation, not restoration of an authorization DENY decision. 3. Reachability analysis The trigger is a local TC control-plane request on an AP_VLAN netdevice. TC configuration normally involves CAP_NET_ADMIN, but the supplied evidence does not establish which user namespace governs every required stage, including AP_VLAN creation, ownership of the underlying wireless interface, and TC setup. It is therefore unknown whether the complete trigger requires host administration or can be performed with delegated or namespace-scoped privileges. The presence of a potentially namespace-aware networking operation is insufficient to set NamespaceScopedPrivilege to YES. No direct packet-triggered path is shown. Existing wireless hardware, an AP configuration, and an AP_VLAN interface are practical prerequisites, but wireless hardware is not treated as rare hardware. There is no race or timing requirement in the shown code. 4. Primitive and severity interpretation The exact defect is an invalid semantic dispatch: `ieee80211_netdev_setup_tc()` forwards a TC offload request for a purely virtual AP_VLAN interface to `drv_net_setup_tc()`, even though the driver has no corresponding hardware-backed interface context. This is not a demonstrated memory-lifetime violation. The object is neither shown to be freed nor used beyond its lifetime, and there is no repeated release or refcount mutation. The supplied code also does not establish that a driver dereferences invalid private storage, writes out of bounds, or crashes. The issue is therefore CLASS_C rather than CLASS_B or CLASS_A. The demonstrated consequence is incorrect TC offload handling and possible network-function degradation. A driver-specific kernel fault remains speculative until the linked syzbot report and relevant `net_setup_tc` implementations are examined. ImportantCandidate is NO because no independently useful corruption, ownership, authorization, or lifetime primitive is established. AutoDowngradeAllowed is YES because the available evidence supports an invalid-state or availability issue without unresolved Important-grade leverage. 5. One-sentence report phrase mac80211 incorrectly forwards TC offload setup for a purely virtual AP_VLAN interface to a wireless driver, potentially causing TC setup failure or driver-specific availability problems without establishing memory corruption or privilege escalation. 6. Manual review recommendation MANUAL CHECK RECOMMENDED Review the referenced syzbot report and affected driver callbacks to determine whether any implementation dereferences absent per-interface private state or produces a kernel crash, but the supplied patch alone does not preserve an Important-class primitive. 7. Call-site confidence Call-site confidence: medium ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: mac80211: don't offload TC setup on AP_VLAN interfaces [ Upstream Commit: 790221efbfece13a2347563b3785aaca48f192e2 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=790221efbfece13a2347563b3785aaca48f192e2 Changed files: net/mac80211/iface.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=790221efbfece13a2347563b3785aaca48f192e2 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98336 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98336 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:N/A:L The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 5.5 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: 1 Paranoid ActionableScore: 2 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).